diff --git a/docs/reference/orcad-operations.md b/docs/reference/orcad-operations.md
index 63f03777c17..adc18586c21 100644
--- a/docs/reference/orcad-operations.md
+++ b/docs/reference/orcad-operations.md
@@ -165,7 +165,12 @@ An external supervisor (systemd, launchd, a process manager). orcad conforms to
   to **stdout**; the supervisor owns capture and rotation. The daemon, being detached, writes
   its own NDJSON lifecycle log to `<data-root>/logs/daemon.log` (suppressed by
   `ORCA_DIAGNOSTICS_DISABLED=1`). Rotation of that file is not implemented — see
-  [What is not covered](#what-is-not-covered).
+  [What is not covered](#what-is-not-covered). orcad records every trace span it emits
+  (git commands, worktree paths, terminal spawns, structured-chat failures and the rest) to
+  `<data-root>/logs/orcad.trace.ndjson`, rotated at 10 MB × 10 files, private to its user and
+  redacted for secret-shaped strings. It stays on the host: a desktop's diagnostics bundle does
+  not collect it. `ORCA_DIAGNOSTICS_DISABLED=1` turns it off, and a logs folder orcad cannot
+  open leaves it off with one stderr warning rather than stopping orcad.
 
 ### orcad supervising the daemon
 
diff --git a/src/main/agent-hooks/first-work-branch-rename.test.ts b/src/main/agent-hooks/first-work-branch-rename.test.ts
index 63b6165ce3a..0e17feb9874 100644
--- a/src/main/agent-hooks/first-work-branch-rename.test.ts
+++ b/src/main/agent-hooks/first-work-branch-rename.test.ts
@@ -63,6 +63,7 @@ import {
   noUpstreamError,
   workingEvent
 } from './first-work-branch-rename-test-harness'
+import { createStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 
 function makeDeps(overrides: Partial<FirstWorkBranchRenameDeps> = {}) {
   return makeBranchRenameDeps(vi.fn, overrides)
@@ -117,6 +118,7 @@ describe('maybeAutoRenameBranchOnFirstWork', () => {
         }
       })
       const feed = new StructuredAgentSessionStatusFeed({
+        logger: createStructuredAgentSessionLogger(),
         sessions: new Map([
           [
             'session',
@@ -215,6 +217,7 @@ describe('maybeAutoRenameBranchOnFirstWork', () => {
     }
     const pending: Promise<void>[] = []
     const feed = new StructuredAgentSessionStatusFeed({
+      logger: createStructuredAgentSessionLogger(),
       sessions: new Map([['session', { journal, params: { location, provider: 'codex' } }]]),
       getRecord: () => null,
       now: () => 1,
diff --git a/src/main/claude/claude-api-retry-idle-sweep.test.ts b/src/main/claude/claude-api-retry-idle-sweep.test.ts
index bac1da60fe7..664f9c135da 100644
--- a/src/main/claude/claude-api-retry-idle-sweep.test.ts
+++ b/src/main/claude/claude-api-retry-idle-sweep.test.ts
@@ -18,6 +18,7 @@ import {
 } from '../native-chat/agent-session-wire/structured-agent-session-host-test-data'
 import { createClaudeJournalTranslator } from './claude-structured-journal-translation'
 import { openTestJournalHostDatabase } from '../native-chat/agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 
 const SWEEP_MS = 5
 const RETRY_GAP_MS = 10 * 60_000
@@ -77,6 +78,7 @@ beforeEach(async () => {
     setOption: async () => undefined
   }
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter,
     journalDatabase: openTestJournalHostDatabase(root),
diff --git a/src/main/claude/claude-api-retry-row.test.ts b/src/main/claude/claude-api-retry-row.test.ts
index a1c8da60cb7..843fbb281d3 100644
--- a/src/main/claude/claude-api-retry-row.test.ts
+++ b/src/main/claude/claude-api-retry-row.test.ts
@@ -12,6 +12,7 @@ import { createDeferredStructuredAgentSessionEventSink } from '../native-chat/ag
 import { unhandledProviderFrameJournalItem } from '../native-chat/agent-session-wire/unhandled-provider-frame'
 import { createClaudeJournalTranslator } from './claude-structured-journal-translation'
 import { openTestJournalHostDatabase } from '../native-chat/agent-session-journal/journal-host-database-test-support'
+import { testEventSinkLogging } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 const IDENTITY: AgentSessionJournalIdentity = {
   sessionId: 'session-1',
@@ -54,7 +55,7 @@ async function statusRowsFor(frames: Record<string, unknown>[]) {
     now: () => 1_700_000_000_000,
     mintEpoch: () => 'epoch-1'
   })
-  const deferred = createDeferredStructuredAgentSessionEventSink()
+  const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
   deferred.bind({ journal, fence: 1, publish: vi.fn() })
   const translator = createClaudeJournalTranslator({ sink: deferred.sink, fallbackIdPrefix: '1' })
   for (const frame of frames) {
diff --git a/src/main/claude/claude-background-wake-retention.test.ts b/src/main/claude/claude-background-wake-retention.test.ts
index 313f9c5de59..a865e1c1b76 100644
--- a/src/main/claude/claude-background-wake-retention.test.ts
+++ b/src/main/claude/claude-background-wake-retention.test.ts
@@ -15,6 +15,7 @@ import { backgroundWakeCapture } from './claude-captured-fold-steer-frames.test-
 import { MOVED_TO_BACKGROUND } from './claude-captured-task-frames.test-fixture'
 import { hostWithParent, parent, producer } from './claude-child-work-producer-harness.test-fixture'
 import { PROVIDER_SESSION_ID } from './claude-structured-session-test-support'
+import { createStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 
 vi.mock('../telemetry/client', () => ({ track: vi.fn() }))
 vi.mock('../telemetry/cohort-classifier', () => ({ getCohortAtEmit: vi.fn(() => ({})) }))
@@ -40,6 +41,7 @@ async function wiredSession() {
     })
   }
   const feed = new StructuredAgentSessionStatusFeed({
+    logger: createStructuredAgentSessionLogger(),
     sessions: new Map([
       [
         parent.sessionId,
diff --git a/src/main/claude/claude-context-usage-restart.test.ts b/src/main/claude/claude-context-usage-restart.test.ts
index 4359799272e..be2c1569ead 100644
--- a/src/main/claude/claude-context-usage-restart.test.ts
+++ b/src/main/claude/claude-context-usage-restart.test.ts
@@ -10,6 +10,7 @@ import { settleStaleStructuredAgentSessionState } from '../native-chat/agent-ses
 import { readAgentJournalTurn } from '../../shared/agent-session-turn-record'
 import { bindClaudeContextUsageCapture } from './claude-context-usage'
 import { createClaudeJournalTranslator } from './claude-structured-journal-translation'
+import { testEventSinkLogging } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 const journals = createTrackedJournalOpener()
 let root: string
@@ -112,7 +113,7 @@ async function openJournal(): Promise<AgentSessionJournal> {
 
 /** One acquisition: a fresh sink and translator over the session's journal. */
 function acquire(journal: AgentSessionJournal) {
-  const deferred = createDeferredStructuredAgentSessionEventSink()
+  const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
   const translator = createClaudeJournalTranslator({ sink: deferred.sink, coalesceMs: 0 })
   deferred.bind({ journal, fence: 1, publish: () => {} })
   const answers: ((value: unknown) => void)[] = []
diff --git a/src/main/claude/claude-context-usage-unloaded-turn.test.ts b/src/main/claude/claude-context-usage-unloaded-turn.test.ts
index ed76a788c18..d98ef7583df 100644
--- a/src/main/claude/claude-context-usage-unloaded-turn.test.ts
+++ b/src/main/claude/claude-context-usage-unloaded-turn.test.ts
@@ -27,6 +27,7 @@ import {
   userFrame
 } from './claude-context-usage-test-support'
 import { createClaudeJournalTranslator } from './claude-structured-journal-translation'
+import { testEventSinkLogging } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 const SESSION = 'orca-session'
 const journals = createTrackedJournalOpener()
@@ -56,7 +57,7 @@ async function openJournal(): Promise<AgentSessionJournal> {
 }
 
 function translate(journal: AgentSessionJournal) {
-  const deferred = createDeferredStructuredAgentSessionEventSink()
+  const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
   const translator = createClaudeJournalTranslator({ sink: deferred.sink, coalesceMs: 0 })
   deferred.bind({ journal, fence: 1, publish: () => {} })
   const settle = async (): Promise<void> => {
diff --git a/src/main/claude/claude-stream-json-connection.test.ts b/src/main/claude/claude-stream-json-connection.test.ts
index 7d198c5a5de..082ed4c12ce 100644
--- a/src/main/claude/claude-stream-json-connection.test.ts
+++ b/src/main/claude/claude-stream-json-connection.test.ts
@@ -21,6 +21,7 @@ import { readClaudeStructuredSessionOptions } from './claude-structured-session-
 import type { ClaudeSession } from './claude-structured-session-state'
 import { CLAUDE_STRUCTURED_BASE_OPTIONS } from './claude-structured-launch-resolution'
 import { openTestJournalHostDatabase } from '../native-chat/agent-session-journal/journal-host-database-test-support'
+import { testEventSinkLogging } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 // These drive the real SDK against the scripted fake CLI, so every assertion is
 // about the environment, argv and frames a real child actually saw.
@@ -385,7 +386,7 @@ describe('Claude stream-json connection', () => {
       now: () => 1_700_000_000_000,
       mintEpoch: () => 'epoch-1'
     })
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
     deferred.bind({ journal, fence: 1, publish: vi.fn() })
     const translator = createClaudeJournalTranslator({ sink: deferred.sink })
     let settled = false
diff --git a/src/main/claude/claude-structured-journal-translation-background-tasks.test.ts b/src/main/claude/claude-structured-journal-translation-background-tasks.test.ts
index c8a9e014950..db3b75ecf32 100644
--- a/src/main/claude/claude-structured-journal-translation-background-tasks.test.ts
+++ b/src/main/claude/claude-structured-journal-translation-background-tasks.test.ts
@@ -15,6 +15,7 @@ import {
 import type { AgentSessionJournal } from '../native-chat/agent-session-journal/journal-store'
 import { createClaudeJournalTranslator } from './claude-structured-journal-translation'
 import { blockOf } from './claude-background-task-row-test-support'
+import { testEventSinkLogging } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 // The frames below are the ones the reported session actually carried: two real
 // failures that printed THREE red rows whose visible text was the wire opcode,
@@ -179,6 +180,7 @@ describe('claude journal translation — background task rows', () => {
       return appendItem(...args)
     })
     const deferred = createDeferredStructuredAgentSessionEventSink({
+      ...testEventSinkLogging(),
       watermarks: {
         pauseQueuedOperations: 1,
         maxQueuedOperations: 4,
@@ -252,7 +254,7 @@ describe('claude journal translation — background task rows', () => {
 
   it('coalesces an unbound overflow patch and aliased final notification', async () => {
     const persisted = new Map<string, AgentJournalItemBody>()
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
     const translator = createClaudeJournalTranslator({
       sink: deferred.sink,
       fallbackIdPrefix: 'test'
@@ -292,7 +294,7 @@ describe('claude journal translation — background task rows', () => {
 
   it('reconciles an aliased notification after a parentless overflow patch was persisted', async () => {
     const persisted = new Map<string, AgentJournalItemBody>()
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
     deferred.bind(persistedTarget(persisted))
     const first = createClaudeJournalTranslator({ sink: deferred.sink, fallbackIdPrefix: 'first' })
     fillLiveTaskRows(first)
@@ -353,7 +355,7 @@ describe('claude journal translation — background task rows', () => {
 
   it('resolves a queued restart identity after the sink rebinds', async () => {
     const persisted = new Map<string, AgentJournalItemBody>()
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
     deferred.bind(persistedTarget(persisted))
 
     const first = createClaudeJournalTranslator({ sink: deferred.sink, fallbackIdPrefix: 'first' })
@@ -371,7 +373,7 @@ describe('claude journal translation — background task rows', () => {
     first.dispose()
     await deferred.drained()
 
-    const restarted = createDeferredStructuredAgentSessionEventSink()
+    const restarted = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
     const second = createClaudeJournalTranslator({
       sink: restarted.sink,
       fallbackIdPrefix: 'second'
@@ -397,7 +399,7 @@ describe('claude journal translation — background task rows', () => {
 
   it('keeps pending writes from distinct runs when a translator is recreated', async () => {
     const persisted = new Map<string, AgentJournalItemBody>()
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
 
     const first = createClaudeJournalTranslator({ sink: deferred.sink, fallbackIdPrefix: 'first' })
     spawnToolCall(first, 'toolu-first')
diff --git a/src/main/claude/claude-structured-journal-translation.test.ts b/src/main/claude/claude-structured-journal-translation.test.ts
index 1b03881e471..0cf7b30368a 100644
--- a/src/main/claude/claude-structured-journal-translation.test.ts
+++ b/src/main/claude/claude-structured-journal-translation.test.ts
@@ -23,6 +23,7 @@ import type { ClaudePendingPrompt } from './claude-structured-prompt-replies'
 import { readAgentJournalTurn } from '../../shared/agent-session-turn-record'
 import { createClaudeJournalTranslator } from './claude-structured-journal-translation'
 import { openTestJournalHostDatabase } from '../native-chat/agent-session-journal/journal-host-database-test-support'
+import { testEventSinkLogging } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 function sinkState() {
   const items: { identity: AgentJournalItemIdentity; body: AgentJournalItemBody }[] = []
@@ -258,7 +259,7 @@ describe('Claude structured journal translation', () => {
       now: () => 1_700_000_000_000,
       mintEpoch: () => 'epoch-1'
     })
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
     deferred.bind({ journal, fence: 1, publish: vi.fn() })
     let scheduled: (() => void) | null = null
     const translator = createClaudeJournalTranslator({
@@ -317,7 +318,7 @@ describe('Claude structured journal translation', () => {
       now: () => 1_700_000_000_000,
       mintEpoch: () => 'epoch-1'
     })
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
     deferred.bind({ journal, fence: 1, publish: vi.fn() })
     const translator = createClaudeJournalTranslator({ sink: deferred.sink })
     const approval = prompt({
diff --git a/src/main/claude/claude-structured-provider-fallback.test.ts b/src/main/claude/claude-structured-provider-fallback.test.ts
index a3a47c8bea8..4cae8b465e9 100644
--- a/src/main/claude/claude-structured-provider-fallback.test.ts
+++ b/src/main/claude/claude-structured-provider-fallback.test.ts
@@ -11,6 +11,7 @@ import { createDeferredStructuredAgentSessionEventSink } from '../native-chat/ag
 import { createClaudeJournalTranslator } from './claude-structured-journal-translation'
 import type { ClaudeStructuredSessionEvent } from './claude-structured-session-state'
 import { openTestJournalHostDatabase } from '../native-chat/agent-session-journal/journal-host-database-test-support'
+import { testEventSinkLogging } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 const IDENTITY: AgentSessionJournalIdentity = {
   sessionId: 'session-1',
@@ -80,7 +81,7 @@ describe('Claude provider fallback', () => {
       now: () => 1_700_000_000_000,
       mintEpoch: () => 'epoch-1'
     })
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
     deferred.bind({
       journal,
       fence: 1,
diff --git a/src/main/claude/claude-structured-session-reading-control.test.ts b/src/main/claude/claude-structured-session-reading-control.test.ts
index d89bd1feb09..d90e5538964 100644
--- a/src/main/claude/claude-structured-session-reading-control.test.ts
+++ b/src/main/claude/claude-structured-session-reading-control.test.ts
@@ -20,6 +20,7 @@ import {
   identityFor,
   PROVIDER_SESSION_ID
 } from './claude-structured-session-test-support'
+import { testEventSinkLogging } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 function controlledSink(): {
   sink: StructuredAgentSessionEventSink
@@ -212,6 +213,7 @@ describe('Claude structured reading control', () => {
     const persisted = new Map<string, AgentJournalItemBody>()
     const target = persistedTarget(persisted)
     const deferred = createDeferredStructuredAgentSessionEventSink({
+      ...testEventSinkLogging(),
       watermarks: {
         pauseQueuedOperations: 1,
         maxQueuedOperations: 4,
diff --git a/src/main/claude/claude-subagent-resume-after-restart.test.ts b/src/main/claude/claude-subagent-resume-after-restart.test.ts
index ef6c067db9e..c4b848eee44 100644
--- a/src/main/claude/claude-subagent-resume-after-restart.test.ts
+++ b/src/main/claude/claude-subagent-resume-after-restart.test.ts
@@ -16,6 +16,7 @@ import { createTrackedJournalOpener } from '../native-chat/agent-session-journal
 import { createDeferredStructuredAgentSessionEventSink } from '../native-chat/agent-session-wire/structured-agent-session-event-sink'
 import { createClaudeJournalTranslator } from './claude-structured-journal-translation'
 import { claudeSubagentGroupBody, claudeSubagentGroupIdentity } from './claude-subagent-group-row'
+import { testEventSinkLogging } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 // Frame orders are real sessions', scrubbed. A resumed agent's frames still name its ORIGINAL
 // spawn call while the announcement names the message call that resumed it, and a new provider
@@ -137,7 +138,7 @@ async function openJournal(): Promise<AgentSessionJournal> {
 
 /** One provider process: a fresh sink and translator over the session's journal. */
 function acquire(journal: AgentSessionJournal) {
-  const deferred = createDeferredStructuredAgentSessionEventSink()
+  const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
   const translator = createClaudeJournalTranslator({ sink: deferred.sink, coalesceMs: 0 })
   deferred.bind({ journal, fence: 1, publish: () => {} })
   const settle = async (): Promise<void> => {
@@ -190,7 +191,7 @@ const rosterIds = (journal: AgentSessionJournal): Set<string> =>
 /** An older build re-rostered a resumed child in the later turn's row, so two rows list it. */
 async function journalAnOlderBuildListedTwice(): Promise<AgentSessionJournal> {
   const journal = await openJournal()
-  const older = createDeferredStructuredAgentSessionEventSink()
+  const older = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
   older.bind({ journal, fence: 1, publish: () => {} })
   const listed = (id: string, state: NativeChatSubagentEntry['state']) => ({
     id,
diff --git a/src/main/claude/claude-subagent-roster.test.ts b/src/main/claude/claude-subagent-roster.test.ts
index 34ff506ee03..2bcffcfb49f 100644
--- a/src/main/claude/claude-subagent-roster.test.ts
+++ b/src/main/claude/claude-subagent-roster.test.ts
@@ -14,6 +14,7 @@ import {
   type StructuredAgentSessionEventSink
 } from '../native-chat/agent-session-wire/structured-agent-session-event-sink'
 import { ClaudeSubagentRoster } from './claude-subagent-roster'
+import { testEventSinkLogging } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 const TURN_1 = 'claude-session:turn-1'
 
@@ -462,7 +463,7 @@ describe('ClaudeSubagentRoster — through the real sink queue', () => {
       },
       appendTombstone: async () => ({ epoch: 'e', sequence: 0 })
     } as unknown as AgentSessionJournal
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
     deferred.bind({
       journal,
       fence: 1,
diff --git a/src/main/codex/codex-provider-retry-idle-sweep.test.ts b/src/main/codex/codex-provider-retry-idle-sweep.test.ts
index b1e8b8b6510..39291b11b19 100644
--- a/src/main/codex/codex-provider-retry-idle-sweep.test.ts
+++ b/src/main/codex/codex-provider-retry-idle-sweep.test.ts
@@ -18,6 +18,7 @@ import {
 } from '../native-chat/agent-session-wire/structured-agent-session-host-test-data'
 import { createCodexJournalTranslator } from './codex-structured-journal-translation'
 import { openTestJournalHostDatabase } from '../native-chat/agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 
 const SWEEP_MS = 5
 const RETRY_GAP_MS = 10 * 60_000
@@ -75,6 +76,7 @@ beforeEach(async () => {
     setOption: async () => undefined
   }
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter,
     journalDatabase: openTestJournalHostDatabase(root),
diff --git a/src/main/codex/codex-structured-journal-goal-resume.test.ts b/src/main/codex/codex-structured-journal-goal-resume.test.ts
index 6df0ba01575..9edeb004332 100644
--- a/src/main/codex/codex-structured-journal-goal-resume.test.ts
+++ b/src/main/codex/codex-structured-journal-goal-resume.test.ts
@@ -12,6 +12,7 @@ import {
 } from '../native-chat/agent-session-wire/structured-agent-session-event-sink'
 import { CodexJournalGoals } from './codex-structured-journal-goals'
 import { MAX_CODEX_GOAL_THREADS } from './codex-structured-journal-limits'
+import { testEventSinkLogging } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 const THREAD = '01a08cc2-f96e-76d0-bb74-88b9bc0b03fc'
 
@@ -34,7 +35,7 @@ function goalFrame(goal: Record<string, unknown> = {}): Record<string, unknown>
 }
 
 function goalJournal(
-  options: Parameters<typeof createDeferredStructuredAgentSessionEventSink>[0] = {}
+  options: Partial<Parameters<typeof createDeferredStructuredAgentSessionEventSink>[0]> = {}
 ) {
   let rowSequence = 0
   let publishes = 0
@@ -43,7 +44,10 @@ function goalJournal(
   let visitedItems = 0
   const rows = new Map<string, AgentJournalRenderItem>()
   const writes: string[] = []
-  const deferred = createDeferredStructuredAgentSessionEventSink(options)
+  const deferred = createDeferredStructuredAgentSessionEventSink({
+    ...testEventSinkLogging(),
+    ...options
+  })
   // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: a fake journal exposing only the members the goal translator and deferred sink call.
   const journal = {
     get epoch() {
diff --git a/src/main/codex/codex-structured-journal-goal-revision.test.ts b/src/main/codex/codex-structured-journal-goal-revision.test.ts
index 4f827600577..aa455403ea7 100644
--- a/src/main/codex/codex-structured-journal-goal-revision.test.ts
+++ b/src/main/codex/codex-structured-journal-goal-revision.test.ts
@@ -14,6 +14,7 @@ import { createTrackedJournalOpener } from '../native-chat/agent-session-journal
 import { readAgentSessionHistory } from '../native-chat/agent-session-wire/agent-session-history-page'
 import { createDeferredStructuredAgentSessionEventSink } from '../native-chat/agent-session-wire/structured-agent-session-event-sink'
 import { CodexJournalGoals } from './codex-structured-journal-goals'
+import { testEventSinkLogging } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 const THREAD = '01a08cc2-f96e-76d0-bb74-88b9bc0b03fc'
 const IDENTITY: AgentSessionJournalIdentity = {
@@ -56,7 +57,7 @@ function goalFrame(goal: Record<string, unknown> = {}) {
 /** The host's own sink bound to a real journal. Its publish is what a subscriber
  *  receives: the page after the cursor it had caught up to. */
 function journalSink(journal: AgentSessionJournal) {
-  const deferred = createDeferredStructuredAgentSessionEventSink()
+  const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
   const published: AgentSessionHistoryPage[] = []
   let subscriberCursor: AgentJournalCursor | null = null
   deferred.bind({
diff --git a/src/main/codex/codex-structured-journal-subagent-readers.test.ts b/src/main/codex/codex-structured-journal-subagent-readers.test.ts
index 21ae85af643..a99b815bff4 100644
--- a/src/main/codex/codex-structured-journal-subagent-readers.test.ts
+++ b/src/main/codex/codex-structured-journal-subagent-readers.test.ts
@@ -21,6 +21,7 @@ import { createDeferredStructuredAgentSessionEventSink } from '../native-chat/ag
 import { createCodexJournalTranslator } from './codex-structured-journal-translation'
 import type { CodexThreadItem } from './codex-thread-item-identity'
 import { openTestJournalHostDatabase } from '../native-chat/agent-session-journal/journal-host-database-test-support'
+import { testEventSinkLogging } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 const SESSION = 'session-codex-children'
 const PARENT = 'thread-parent'
@@ -52,7 +53,7 @@ async function openJournal(root: string): Promise<AgentSessionJournal> {
 async function session() {
   const root = await mkdtemp(join(tmpdir(), 'orca-codex-children-'))
   let journal = await openJournal(root)
-  const deferred = createDeferredStructuredAgentSessionEventSink()
+  const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
   const activities: (AgentSessionTurnActivity | null)[] = []
   deferred.bind({
     journal,
diff --git a/src/main/codex/codex-structured-journal-translation-settlement.test.ts b/src/main/codex/codex-structured-journal-translation-settlement.test.ts
index 344d99e03b4..6f00bdbe2b8 100644
--- a/src/main/codex/codex-structured-journal-translation-settlement.test.ts
+++ b/src/main/codex/codex-structured-journal-translation-settlement.test.ts
@@ -25,6 +25,7 @@ import {
   CODEX_USER_INPUT_METHOD
 } from './codex-structured-prompt-replies'
 import type { CodexStructuredSessionEvent } from './codex-structured-session-adapter'
+import { testEventSinkLogging } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 const SESSION_ID = 'session-1'
 const THREAD_ID = 'thread-abc'
@@ -129,6 +130,7 @@ function deferredTarget(
 
 function hardWatermarkDeferred() {
   return createDeferredStructuredAgentSessionEventSink({
+    ...testEventSinkLogging(),
     watermarks: {
       pauseQueuedBytes: 1,
       maxQueuedBytes: 1,
diff --git a/src/main/codex/codex-structured-journal-translation-turn-lifecycle.test.ts b/src/main/codex/codex-structured-journal-translation-turn-lifecycle.test.ts
index f9714bbe062..07115c4b4e7 100644
--- a/src/main/codex/codex-structured-journal-translation-turn-lifecycle.test.ts
+++ b/src/main/codex/codex-structured-journal-translation-turn-lifecycle.test.ts
@@ -26,6 +26,7 @@ import {
 import { createCodexStructuredNotificationRetry } from './codex-structured-notification-retry'
 import type { CodexStructuredSessionEvent } from './codex-structured-session-adapter'
 import type { CodexSession } from './codex-structured-session-state'
+import { testEventSinkLogging } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 const SESSION_ID = 'session-1'
 const THREAD_ID = 'thread-abc'
@@ -223,7 +224,7 @@ describe('codex turn lifecycle rows', () => {
       now: () => 9_000,
       stateDirectory: join(root, SESSION_ID)
     })
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
     const translator = createCodexJournalTranslator({
       sink: deferred.sink,
       sessionId: SESSION_ID,
diff --git a/src/main/codex/codex-structured-journal-translation.test.ts b/src/main/codex/codex-structured-journal-translation.test.ts
index 676d9054ed7..523dd1894f8 100644
--- a/src/main/codex/codex-structured-journal-translation.test.ts
+++ b/src/main/codex/codex-structured-journal-translation.test.ts
@@ -18,6 +18,7 @@ import {
   CODEX_USER_INPUT_METHOD
 } from './codex-structured-prompt-replies'
 import type { CodexStructuredSessionEvent } from './codex-structured-session-adapter'
+import { testEventSinkLogging } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 const SESSION_ID = 'session-1'
 const THREAD_ID = 'thread-abc'
@@ -127,6 +128,7 @@ function deferredTarget(
 
 function hardWatermarkDeferred() {
   return createDeferredStructuredAgentSessionEventSink({
+    ...testEventSinkLogging(),
     watermarks: {
       pauseQueuedBytes: 1,
       maxQueuedBytes: 1,
@@ -713,6 +715,7 @@ describe('codex journal translation', () => {
     const publishes: string[] = []
     const readingControl = { pauseReading: vi.fn(), resumeReading: vi.fn() }
     const deferred = createDeferredStructuredAgentSessionEventSink({
+      ...testEventSinkLogging(),
       watermarks: {
         pauseQueuedBytes: 1,
         maxQueuedBytes: 1,
diff --git a/src/main/codex/codex-structured-journal-turn-settles-once-journal.test.ts b/src/main/codex/codex-structured-journal-turn-settles-once-journal.test.ts
index 7011cfa0302..da24f836d1a 100644
--- a/src/main/codex/codex-structured-journal-turn-settles-once-journal.test.ts
+++ b/src/main/codex/codex-structured-journal-turn-settles-once-journal.test.ts
@@ -13,6 +13,7 @@ import {
 import { createTrackedJournalOpener } from '../native-chat/agent-session-journal/journal-host-database-test-support'
 import { createDeferredStructuredAgentSessionEventSink } from '../native-chat/agent-session-wire/structured-agent-session-event-sink'
 import { createCodexJournalTranslator } from './codex-structured-journal-translation'
+import { testEventSinkLogging } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 const SESSION = 'session-codex-failed-turn'
 const THREAD = 'thread-abc'
@@ -39,7 +40,7 @@ async function session() {
     stateDirectory: root,
     now: () => 1_000
   })
-  const deferred = createDeferredStructuredAgentSessionEventSink()
+  const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
   deferred.bind({ journal, fence: 1, publish: () => {} })
   cleanups.push(async () => {
     deferred.close()
diff --git a/src/main/codex/codex-structured-question-order.test.ts b/src/main/codex/codex-structured-question-order.test.ts
index 069fe4eb048..8ad4b75bd38 100644
--- a/src/main/codex/codex-structured-question-order.test.ts
+++ b/src/main/codex/codex-structured-question-order.test.ts
@@ -36,6 +36,7 @@ import {
   structuredQuestionTranscript
 } from '../../renderer/src/components/native-chat/structured-agent-question-projection'
 import { openTestJournalHostDatabase } from '../native-chat/agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 
@@ -93,6 +94,7 @@ beforeEach(async () => {
   }
   store = await openTestAgentSessionRecordStore(root)
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter,
     journalDatabase: openTestJournalHostDatabase(root),
diff --git a/src/main/native-chat/agent-session-journal/journal-open-failure.test.ts b/src/main/native-chat/agent-session-journal/journal-open-failure.test.ts
index 44a68b7696b..787b1aa6491 100644
--- a/src/main/native-chat/agent-session-journal/journal-open-failure.test.ts
+++ b/src/main/native-chat/agent-session-journal/journal-open-failure.test.ts
@@ -1,7 +1,7 @@
 import { mkdtemp, readFile, rm, writeFile } from 'node:fs/promises'
 import { tmpdir } from 'node:os'
 import { join } from 'node:path'
-import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+import { afterEach, beforeEach, describe, expect, it } from 'vitest'
 import { agentSessionRefusalError } from '../../../shared/agent-session-wire-refusals'
 import { NO_LEGACY_JOURNAL_RECORDS, openJournalDatabase } from './journal-database'
 import {
@@ -14,6 +14,7 @@ import {
 import { AgentSessionJournalError } from './journal-write-guards'
 import { journalDatabasePath } from './journal-host-database'
 import { replayJournal } from './journal-open'
+import { recordingStructuredAgentSessionLogger } from '../agent-session-wire/structured-agent-session-logger-test-support'
 
 let root: string
 
@@ -111,30 +112,39 @@ describe('classifyJournalOpenFailure', () => {
 
 describe('journalOpenReadRefusal', () => {
   it('names the reason, keeps the message the code and the storage text only as the cause', () => {
-    vi.spyOn(console, 'warn').mockImplementation(() => undefined)
+    const log = recordingStructuredAgentSessionLogger()
     const storage = nodeSqliteError(26)
-    const refusal = journalOpenReadRefusal(storage)
+    const refusal = journalOpenReadRefusal(storage, log.logger, 'session-1')
     expect(refusal.message).toBe('agent_session_journal_unreadable')
     expect(refusal.refusal).toMatchObject({
       code: 'agent_session_journal_unreadable',
       details: { reason: 'journalCorrupt' }
     })
     expect(refusal.cause).toBe(storage)
-    vi.restoreAllMocks()
+    expect(log.entries).toEqual([
+      {
+        level: 'warn',
+        message: 'opening the conversation for a read failed',
+        fields: { scope: 'open-for-read', sessionId: 'session-1', error: storage }
+      }
+    ])
   })
 
   it('passes a refusal the open already raised through unchanged', () => {
     const raised = agentSessionRefusalError('agent_session_identity_required', {
       reason: 'recordMissing'
     })
-    expect(journalOpenReadRefusal(raised)).toBe(raised)
+    expect(
+      journalOpenReadRefusal(raised, recordingStructuredAgentSessionLogger().logger, 's')
+    ).toBe(raised)
   })
 })
 
 describe('createJournalOpenReadRefusals', () => {
   it('logs a session once per failure until it opens, and each session on its own', () => {
-    const warn = vi.spyOn(console, 'warn').mockImplementation(() => undefined)
-    const refusals = createJournalOpenReadRefusals()
+    const log = recordingStructuredAgentSessionLogger()
+    const logged = () => log.entries.map((entry) => entry.fields.sessionId)
+    const refusals = createJournalOpenReadRefusals(log.logger)
     const denied = systemError('EACCES', -13)
     const corrupt = nodeSqliteError(26)
 
@@ -143,17 +153,21 @@ describe('createJournalOpenReadRefusals', () => {
       expect(refusal.refusal).toMatchObject({ details: { reason: 'journalUnavailable' } })
       expect(refusal.cause).toBe(denied)
     }
-    expect(warn).toHaveBeenCalledTimes(1)
+    expect(logged()).toEqual(['session-1'])
     refusals.refusal('session-2', denied)
-    expect(warn).toHaveBeenCalledTimes(2)
+    expect(logged()).toEqual(['session-1', 'session-2'])
     expect(refusals.refusal('session-1', corrupt).refusal).toMatchObject({
       details: { reason: 'journalCorrupt' }
     })
-    expect(warn).toHaveBeenCalledTimes(3)
+    expect(logged()).toEqual(['session-1', 'session-2', 'session-1'])
     refusals.forget('session-1')
     refusals.refusal('session-1', corrupt)
-    expect(warn).toHaveBeenCalledTimes(4)
-    vi.restoreAllMocks()
+    expect(log.scopes()).toEqual([
+      'open-for-read',
+      'open-for-read',
+      'open-for-read',
+      'open-for-read'
+    ])
   })
 })
 
@@ -176,13 +190,12 @@ describe('a journal a newer Orca wrote', () => {
   })
 
   it('refuses a read with the same reason', () => {
-    vi.spyOn(console, 'warn').mockImplementation(() => undefined)
-    expect(journalOpenReadRefusal(readOnly()).refusal).toMatchObject({
+    const { logger } = recordingStructuredAgentSessionLogger()
+    expect(journalOpenReadRefusal(readOnly(), logger, 'session-1').refusal).toMatchObject({
       details: { reason: 'journalWrittenByNewerOrca' }
     })
-    expect(createJournalOpenReadRefusals().refusal('session-1', readOnly()).refusal).toMatchObject({
-      details: { reason: 'journalWrittenByNewerOrca' }
-    })
-    vi.restoreAllMocks()
+    expect(
+      createJournalOpenReadRefusals(logger).refusal('session-1', readOnly()).refusal
+    ).toMatchObject({ details: { reason: 'journalWrittenByNewerOrca' } })
   })
 })
diff --git a/src/main/native-chat/agent-session-journal/journal-open-failure.ts b/src/main/native-chat/agent-session-journal/journal-open-failure.ts
index 5e014c279cb..d154e1b29e6 100644
--- a/src/main/native-chat/agent-session-journal/journal-open-failure.ts
+++ b/src/main/native-chat/agent-session-journal/journal-open-failure.ts
@@ -13,6 +13,7 @@ import {
 } from '../../../shared/agent-session-wire-refusals'
 import { isSqliteCorruption } from '../../sqlite/sqlite-read-failure'
 import { AgentSessionJournalError } from './journal-write-guards'
+import type { StructuredAgentSessionLogger } from '../agent-session-wire/structured-agent-session-logger'
 
 type JournalRefusalReason = AgentSessionRefusalReason<'agent_session_journal_unreadable'>
 
@@ -107,11 +108,15 @@ export function journalOpenRefusalError(error: unknown): AgentSessionRefusalErro
  * (a path, "file is not a database") goes to the log only; the reader gets the classified refusal,
  * whose message stays the bare code.
  */
-export function journalOpenReadRefusal(error: unknown): AgentSessionRefusalError {
+export function journalOpenReadRefusal(
+  error: unknown,
+  logger: StructuredAgentSessionLogger,
+  sessionId: string
+): AgentSessionRefusalError {
   if (isAgentSessionRefusalError(error)) {
     return error
   }
-  return unreadableRefusal(error, journalRefusalReason(error), true)
+  return unreadableRefusal(error, journalRefusalReason(error), { logger, sessionId })
 }
 
 const MAX_LOGGED_SESSIONS = 256
@@ -120,7 +125,7 @@ const MAX_LOGGED_SESSIONS = 256
  * The read door's refusals for one host. A reader reconnects on a timer while an open can clear,
  * so a session's failure is logged once until that session opens or the failure changes.
  */
-export function createJournalOpenReadRefusals() {
+export function createJournalOpenReadRefusals(logger: StructuredAgentSessionLogger) {
   const logged = new Map<string, string>()
   return {
     refusal: (sessionId: string, error: unknown): AgentSessionRefusalError => {
@@ -134,7 +139,7 @@ export function createJournalOpenReadRefusals() {
       if (!repeat && (logged.has(sessionId) || logged.size < MAX_LOGGED_SESSIONS)) {
         logged.set(sessionId, failure)
       }
-      return unreadableRefusal(error, reason, !repeat)
+      return unreadableRefusal(error, reason, repeat ? null : { logger, sessionId })
     },
     /** The session opened or closed: its next failure is news. */
     forget: (sessionId: string): void => {
@@ -146,11 +151,13 @@ export function createJournalOpenReadRefusals() {
 function unreadableRefusal(
   error: unknown,
   reason: JournalRefusalReason,
-  log: boolean
+  log: { logger: StructuredAgentSessionLogger; sessionId: string } | null
 ): AgentSessionRefusalError {
-  if (log) {
-    console.warn('[agent-session] opening the conversation for a read failed:', error)
-  }
+  log?.logger.warn('opening the conversation for a read failed', {
+    scope: 'open-for-read',
+    sessionId: log.sessionId,
+    error
+  })
   const code = 'agent_session_journal_unreadable'
   return new AgentSessionRefusalError(refuse(code, { reason }, code), { cause: error })
 }
diff --git a/src/main/native-chat/agent-session-journal/journal-per-session-import.test.ts b/src/main/native-chat/agent-session-journal/journal-per-session-import.test.ts
index c9737bf2007..9ec154d0e5d 100644
--- a/src/main/native-chat/agent-session-journal/journal-per-session-import.test.ts
+++ b/src/main/native-chat/agent-session-journal/journal-per-session-import.test.ts
@@ -28,6 +28,7 @@ import {
 import { journalDirectoryFor, legacyJournalDatabaseFile } from './journal-paths'
 import { importPerSessionJournal } from './journal-per-session-import'
 import { readJournalSessionEpoch, type JournalStoredRow } from './journal-row-table'
+import { createStructuredAgentSessionLogger } from '../agent-session-wire/structured-agent-session-logger'
 
 vi.mock('node:fs', async (importOriginal) => {
   const actual = await importOriginal<typeof NodeFs>()
@@ -221,6 +222,7 @@ describe('importing a per-chat journal', () => {
 
     const journal = await openChat()
     const withdrawal = createStructuredAgentSessionRestartOfferWithdrawal({
+      logger: createStructuredAgentSessionLogger(),
       sessions: new Map([[IDENTITY.sessionId, { journal, child: null }]]),
       now: () => clock,
       enqueue: (operation) => operation()
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-accept-then-deliver.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-accept-then-deliver.test.ts
index a80c147607d..b3f91aea700 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-accept-then-deliver.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-accept-then-deliver.test.ts
@@ -45,6 +45,7 @@ import {
 import { agentSessionFailureFact } from '../../../shared/agent-session-failure'
 import { agentSessionFailureWords } from '../../../shared/agent-session-failure-words'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 
@@ -76,6 +77,7 @@ const spawnChild: StructuredAgentSessionAdapter['acquire'] = async ({ fence, spa
 
 async function startHost(): Promise<void> {
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: {
       acquire,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-acquisition-options.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-acquisition-options.test.ts
index a0d2f0fdb7d..c98854292d5 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-acquisition-options.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-acquisition-options.test.ts
@@ -20,6 +20,7 @@ import { openTestAttachConversation } from './structured-agent-session-attach-te
 import { performAttach } from './structured-agent-session-attach-flow'
 import type { AgentSessionCreatePhaseRecorder } from '../../observability/agent-session-instrumentation'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const NOW = 1_800_000_000_000
 const SESSION = 'legacy-session'
@@ -151,6 +152,7 @@ describe('structured session acquisition options', () => {
 
     let firstJournal: AgentSessionJournal | undefined
     const first = await performAttach({
+      logger: createStructuredAgentSessionLogger(),
       store: initialStore,
       adapter: withHistory('created'),
       openConversation: openTestAttachConversation(openTestJournalHostDatabase(root!)),
@@ -188,6 +190,7 @@ describe('structured session acquisition options', () => {
     const releasedFence = store.getRecord(SESSION)?.lease.runtimeFence ?? 0
 
     const second = await performAttach({
+      logger: createStructuredAgentSessionLogger(),
       store,
       adapter: withHistory('resumed'),
       openConversation: openTestAttachConversation(openTestJournalHostDatabase(root!)),
@@ -219,6 +222,7 @@ describe('structured session acquisition options', () => {
     const recordPhase = vi.fn<AgentSessionCreatePhaseRecorder>()
 
     const created = await performAttach({
+      logger: createStructuredAgentSessionLogger(),
       store,
       adapter: sessionAdapter,
       openConversation: openTestAttachConversation(openTestJournalHostDatabase(root!)),
@@ -248,6 +252,7 @@ describe('structured session acquisition options', () => {
     const sessionAdapter = adapter({ origin: 'created' })
     const attempt = async (options: Readonly<Record<string, string>>, spawnToken: string) =>
       performAttach({
+        logger: createStructuredAgentSessionLogger(),
         store,
         adapter: sessionAdapter,
         openConversation: openTestAttachConversation(openTestJournalHostDatabase(root!)),
@@ -278,6 +283,7 @@ describe('structured session acquisition options', () => {
     const store = await openTestAgentSessionRecordStore(root)
 
     const created = await performAttach({
+      logger: createStructuredAgentSessionLogger(),
       store,
       adapter: adapter({ origin: 'created' }),
       openConversation: openTestAttachConversation(openTestJournalHostDatabase(root!)),
@@ -308,6 +314,7 @@ describe('structured session acquisition options', () => {
     })
     const releasedFence = resumedStore.getRecord(SESSION)?.lease.runtimeFence ?? 0
     const resumed = await performAttach({
+      logger: createStructuredAgentSessionLogger(),
       store: resumedStore,
       adapter: adapter({
         origin: 'resumed',
@@ -350,6 +357,7 @@ describe('structured session acquisition options', () => {
     })
 
     const created = await performAttach({
+      logger: createStructuredAgentSessionLogger(),
       store,
       adapter: sessionAdapter,
       openConversation: openTestAttachConversation(openTestJournalHostDatabase(root!)),
@@ -386,6 +394,7 @@ describe('structured session acquisition options', () => {
 
     await expect(
       performAttach({
+        logger: createStructuredAgentSessionLogger(),
         store,
         adapter: failingAdapter,
         openConversation: openTestAttachConversation(openTestJournalHostDatabase(root!)),
@@ -479,6 +488,7 @@ describe('structured session acquisition options', () => {
         fence: number | null
       ) =>
         performAttach({
+          logger: createStructuredAgentSessionLogger(),
           store: target,
           adapter: failingAdapter,
           openConversation: openTestAttachConversation(
@@ -580,6 +590,7 @@ describe('the tab a create reserves', () => {
 
   function attachWith(store: AgentSessionRecordStore, surfaceTabId?: string) {
     return performAttach({
+      logger: createStructuredAgentSessionLogger(),
       store,
       adapter: adapter({ origin: 'created' }),
       openConversation: openTestAttachConversation(openTestJournalHostDatabase(root!)),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-adopted-import.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-adopted-import.test.ts
index 6bb43fb9d31..76a276abd23 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-adopted-import.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-adopted-import.test.ts
@@ -19,6 +19,7 @@ import { AgentSessionJournal } from '../agent-session-journal/journal-store'
 import * as legacyImport from '../agent-session-journal/journal-legacy-import'
 import { StructuredAgentSessionHost } from './structured-agent-session-host'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const NOW = 1_800_000_000_000
 const SESSION = 'codex_adopting_session'
@@ -122,6 +123,7 @@ async function attach(
 ) {
   store ??= await openTestAgentSessionRecordStore(root!)
   return performAttach({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: sessionAdapter,
     openConversation: openTestAttachConversation(openTestJournalHostDatabase(root!)),
@@ -233,6 +235,7 @@ describe('adopting a provider conversation on create', () => {
     await writeCodexRollout(transcriptPath, 'valid source')
     store = await openTestAgentSessionRecordStore(root)
     const host = new StructuredAgentSessionHost({
+      logger: createStructuredAgentSessionLogger(),
       store,
       adapter: adapter(),
       journalDatabase: openTestJournalHostDatabase(root),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-agent-start.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-agent-start.ts
index a4c93fa00f8..6fbcca0dce2 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-agent-start.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-agent-start.ts
@@ -79,7 +79,11 @@ export function ensureStructuredAgentSessionAgentForOperation(
 ): Promise<StructuredAgentSessionResumeOutcome> {
   return ensureStructuredAgentSessionAgent(context, sessionId).catch((error: unknown) => {
     // The error is Orca's own and goes to the log; the refusal says only that the start failed.
-    console.warn('[agent-session] starting the agent for an operation failed:', error)
+    context.deps.logger.warn('starting the agent for an operation failed', {
+      scope: 'operation-agent-start',
+      sessionId,
+      error
+    })
     return {
       ok: false,
       refusal: refuseUnclassified(
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-append-delivery.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-append-delivery.test.ts
index bda7cc9330f..e2adb2953cb 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-append-delivery.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-append-delivery.test.ts
@@ -26,6 +26,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 const EXIT_REASON = 'Claude Code is not signed in. Sign in with the Claude CLI'
@@ -128,6 +129,7 @@ beforeEach(async () => {
   }))
   store = await openTestAgentSessionRecordStore(root)
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: {
       acquire,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-at-rest-commands.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-at-rest-commands.test.ts
index 063cf84ebd7..140a9920115 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-at-rest-commands.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-at-rest-commands.test.ts
@@ -18,6 +18,7 @@ import type { AgentSessionRecordStore } from '../../runtime/agent-session-record
 import { openTestAgentSessionRecordStore } from '../../runtime/agent-session-record-store-test-harness'
 import type { StructuredAgentSessionAdapter } from './structured-agent-session-adapter'
 import { StructuredAgentSessionHost } from './structured-agent-session-host'
+import { recordingStructuredAgentSessionLogger } from './structured-agent-session-logger-test-support'
 import {
   HOST_TEST_LOCATION,
   HOST_TEST_NOW,
@@ -87,6 +88,7 @@ async function openHost(catalog = catalogFor(workspace)): Promise<void> {
     adapter: adapter(catalog),
     journalDatabase: openTestJournalHostDatabase(directory),
     claimKeyId: 'key',
+    logger: recordingStructuredAgentSessionLogger().logger,
     now: () => clock,
     probeOwner: async () => ({ outcome: 'pid-absent' })
   })
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-attach-flow.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-attach-flow.ts
index c469035c468..d1b6cd28087 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-attach-flow.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-attach-flow.ts
@@ -44,10 +44,12 @@ import {
 } from '../../observability/agent-session-instrumentation'
 import type { ProviderHistoryWindow } from '../agent-session-journal/journal-submission-reconciler'
 import type { AgentSessionJournal } from '../agent-session-journal/journal-store'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 export type AttachFlowInput = {
   store: AgentSessionRecordStore
   adapter: StructuredAgentSessionAdapter
+  logger: StructuredAgentSessionLogger
   authority: AgentSessionAttachAuthority
   callerKey: string
   params: AgentSessionAttachParams
@@ -206,7 +208,11 @@ export async function performAttach(
     const thrown = failed ? error : preSpawnFailureInWords(error, wording)
     if (failed || thrown !== error) {
       // The answer carries only its sentence, so what failed is kept here.
-      console.warn('[agent-session] provider start failed:', error)
+      input.logger.warn('starting the provider failed', {
+        scope: 'provider-start',
+        sessionId,
+        error
+      })
     }
     return (
       failed ?? {
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-attach-orchestration.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-attach-orchestration.ts
index 9cfdf6a9b87..d8f89065de4 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-attach-orchestration.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-attach-orchestration.ts
@@ -135,6 +135,7 @@ async function runAttach(
     const attached = await performAttach({
       store: context.deps.store,
       adapter: context.deps.adapter,
+      logger: context.deps.logger,
       eventSink: attemptSink.sink,
       // The superseded child's writes settle into its own journal before a new child starts.
       onAcquiring: async () => {
@@ -201,7 +202,7 @@ async function runAttach(
           }
         }
         await recoverStructuredRewind(
-          context.deps.store,
+          context.deps,
           sessionId,
           attached.journal,
           fence,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-attach-test-conversation.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-attach-test-conversation.ts
index aa0ae9e29e8..7a9f758858a 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-attach-test-conversation.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-attach-test-conversation.ts
@@ -3,6 +3,7 @@ import type { JournalHostDatabase } from '../agent-session-journal/journal-host-
 import type { AgentSessionJournal } from '../agent-session-journal/journal-store'
 import type { StructuredAgentSessionAdapter } from './structured-agent-session-adapter'
 import { openStructuredAgentSessionConversationJournal } from './structured-agent-session-conversation-open'
+import { recordingStructuredAgentSessionLogger } from './structured-agent-session-logger-test-support'
 
 /** For a test that attaches without a host: the conversation's journal, through the one open a
  *  host would take, so the attach under test adopts it the way it adopts the host's. */
@@ -12,8 +13,12 @@ export function openTestAttachConversation(
 ): (record: AgentSessionRecord) => Promise<AgentSessionJournal> {
   return async (record) =>
     (
-      await openStructuredAgentSessionConversationJournal({ journalDatabase, adapter }, record, {
-        acquisition: true
-      })
+      await openStructuredAgentSessionConversationJournal(
+        { journalDatabase, adapter, logger: recordingStructuredAgentSessionLogger().logger },
+        record,
+        {
+          acquisition: true
+        }
+      )
     ).session.journal
 }
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-background-task-channel.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-background-task-channel.test.ts
index 11505b6c204..92c52f88a68 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-background-task-channel.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-background-task-channel.test.ts
@@ -10,6 +10,7 @@ import type {
   StructuredAgentSessionHostSession
 } from './structured-agent-session-host-types'
 import type { AgentSessionSubscribers } from './structured-agent-session-subscribers'
+import { recordingStructuredAgentSessionLogger } from './structured-agent-session-logger-test-support'
 
 const child: AgentChildWorkView = {
   id: 'child-1',
@@ -31,7 +32,7 @@ function channelOver(
 ) {
   const sessions = new StructuredAgentSessionConversations({
     deliver: () => {},
-    onDeliveryError: () => {},
+    logger: recordingStructuredAgentSessionLogger().logger,
     now: () => 1
   })
   const sent = vi.fn()
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-chat-stop.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-chat-stop.ts
index af618040fa3..70707019295 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-chat-stop.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-chat-stop.ts
@@ -108,7 +108,12 @@ export function mutateWithChatStop<TValue>(
         { sessionId, adapter: context.deps.adapter },
         windDown,
         () => context.stopAgent(sessionId),
-        (error) => context.deps.onEventSinkError?.({ sessionId, error })
+        (error) =>
+          context.deps.logger.warn("ending a stopped chat's provider session failed", {
+            scope: 'chat-stop',
+            sessionId,
+            error
+          })
       )
     }
   })
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-claude-compact-stop.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-claude-compact-stop.test.ts
index 041b6580ea2..bbdc2b50b2f 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-claude-compact-stop.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-claude-compact-stop.test.ts
@@ -28,6 +28,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 
@@ -70,6 +71,7 @@ beforeEach(async () => {
   })
   store = await openTestAgentSessionRecordStore(root)
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     // The production router is what declares create support; the bare adapter only knows locations.
     adapter: Object.assign(adapter, { supportsCreate: () => true }),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-claude-echo-working.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-claude-echo-working.test.ts
index 1ba4f13e4ea..747319c3c66 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-claude-echo-working.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-claude-echo-working.test.ts
@@ -27,6 +27,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 
@@ -66,6 +67,7 @@ beforeEach(async () => {
   })
   store = await openTestAgentSessionRecordStore(root)
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: Object.assign(adapter, { supportsCreate: () => true }),
     journalDatabase: openTestJournalHostDatabase(root),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-claude-option-queue.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-claude-option-queue.test.ts
index 6398d96ab0a..1bb3d36a5c4 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-claude-option-queue.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-claude-option-queue.test.ts
@@ -16,6 +16,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-claude' }
 const CLAUDE_SESSION = '019fd532-7c11-7a90-b6de-4e1a2c3d5f61'
@@ -83,6 +84,7 @@ beforeEach(async () => {
   optionWritable = Promise.resolve()
   store = await openTestAgentSessionRecordStore(root)
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: adapter(),
     journalDatabase: openTestJournalHostDatabase(root),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-claude-queued-stop.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-claude-queued-stop.test.ts
index 879f83b8a6c..2531450fd22 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-claude-queued-stop.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-claude-queued-stop.test.ts
@@ -29,6 +29,7 @@ import {
   hostTestOperationId,
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 // As Claude Code 2.1.280 advertises them on a turn's system/init frame.
@@ -82,6 +83,7 @@ beforeEach(async () => {
   })
   store = await openTestAgentSessionRecordStore(root)
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: Object.assign(adapter, { supportsCreate: () => true }),
     journalDatabase: openTestJournalHostDatabase(root),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-claude-root-exit.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-claude-root-exit.test.ts
index 778bd3cc2fa..f09fe672b5e 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-claude-root-exit.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-claude-root-exit.test.ts
@@ -17,6 +17,7 @@ import type { AgentSessionAttachParams } from './structured-agent-session-attach
 import { stopStructuredAgentSessionAgentUnderSerialize } from './structured-agent-session-host-lifetime'
 import { StructuredAgentSessionHostRuntimeState } from './structured-agent-session-host-runtime-state'
 import type { StructuredAgentSessionHostSession } from './structured-agent-session-host-types'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const NOW = 1_788_727_031_330
 const roots: string[] = []
@@ -121,7 +122,8 @@ describe('Claude root-exit stop', () => {
       adapter,
       // The one database the store and the journal share, as the runtime installs them.
       journalDatabase: openTestJournalHostDatabase(stateDirectory),
-      claimKeyId: 'key-1'
+      claimKeyId: 'key-1',
+      logger: createStructuredAgentSessionLogger()
     }
     const runtimeState = new StructuredAgentSessionHostRuntimeState(deps)
 
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-claude-stop-ends-session.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-claude-stop-ends-session.test.ts
index ad314376b1a..845647f3c0a 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-claude-stop-ends-session.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-claude-stop-ends-session.test.ts
@@ -32,6 +32,7 @@ import { openTestAgentSessionRecordStore } from '../../runtime/agent-session-rec
 import { structuredClaudeLifecycleEvent } from '../../runtime/structured-claude-runtime-adapter'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
 import { StructuredAgentSessionHost } from './structured-agent-session-host'
+import { recordingStructuredAgentSessionLogger } from './structured-agent-session-logger-test-support'
 import {
   HOST_TEST_NOW as NOW,
   HOST_TEST_SESSION as SESSION,
@@ -52,7 +53,7 @@ let store: AgentSessionRecordStore
 let queued: string[]
 let claude: ReturnType<typeof fakeClaude>
 let events: ClaudeStructuredSessionEvent[]
-let sinkErrors: unknown[]
+let logs: ReturnType<typeof recordingStructuredAgentSessionLogger>
 // The host's status row and child records, as the app's hook server holds them.
 let server: AgentHookServer
 let statusSubject: AgentStatusStructuredSessionSubject | undefined
@@ -62,7 +63,7 @@ beforeEach(async () => {
   resetHostTestOperationIds()
   queued = []
   events = []
-  sinkErrors = []
+  logs = recordingStructuredAgentSessionLogger()
   server = new AgentHookServer()
   statusSubject = undefined
   claude = fakeClaude({
@@ -107,7 +108,7 @@ beforeEach(async () => {
     journalDatabase: openTestJournalHostDatabase(root),
     claimKeyId: 'key-1',
     mintSpawnToken: () => 'spawn-a',
-    onEventSinkError: ({ error }) => sinkErrors.push(error),
+    logger: logs.logger,
     statusSink: {
       publish: (summary, subject) => {
         statusSubject = subject
@@ -601,10 +602,15 @@ it('still answers the Stop, with its row, when the child cannot be proven gone;
   await laneDrained()
 
   expect(await statusTexts()).toEqual(['Cancellation requested.'])
-  expect(sinkErrors).toEqual([
+  expect(logs.entries).toEqual([
     expect.objectContaining({
-      name: 'StructuredAgentSessionEvictionError',
-      step: 'stop-provider-child'
+      fields: expect.objectContaining({
+        scope: 'chat-stop',
+        error: expect.objectContaining({
+          name: 'StructuredAgentSessionEvictionError',
+          step: 'stop-provider-child'
+        })
+      })
     })
   ])
   connection.close = close
@@ -660,7 +666,7 @@ it('keeps a second Stop pressed while the first ends the child quiet', async ()
   expect(connection.closed).toBe(true)
   expect(connection.calls.filter((call) => call.subtype === 'interrupt')).toHaveLength(1)
   expect(await statusTexts()).toEqual(['Cancellation requested.'])
-  expect(sinkErrors).toEqual([])
+  expect(logs.entries).toEqual([])
 })
 
 const BRANCH_QUESTION = {
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-close-verdict.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-close-verdict.test.ts
index 83d80437de3..4b51f9cfe77 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-close-verdict.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-close-verdict.test.ts
@@ -31,6 +31,7 @@ import {
   childEndCauseOfEndedEvent,
   turnVerdictForChildEnd
 } from './structured-agent-session-stale-turn-verdict'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CUT_TURN = { provider: 'codex' as const, threadId: THREAD, turnId: 'cut-turn', ordinal: 1 }
 
@@ -51,6 +52,7 @@ beforeEach(() => {
   exitObservedFirst = false
   closeCalls = 0
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store: state.store,
     adapter: {
       ...adapter(),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-codex-stop-row.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-codex-stop-row.test.ts
index 8833ac4ee31..9103393c26c 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-codex-stop-row.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-codex-stop-row.test.ts
@@ -24,6 +24,7 @@ import {
   hostTestOperationId,
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 
@@ -51,6 +52,7 @@ beforeEach(async () => {
   }
   const store = await openTestAgentSessionRecordStore(root)
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: Object.assign(adapterFor(codex), { supportsCreate: () => true }),
     journalDatabase: openTestJournalHostDatabase(root),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-conversation-close.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-conversation-close.test.ts
index 2dd2b5229aa..499c5f3ff48 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-conversation-close.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-conversation-close.test.ts
@@ -317,8 +317,14 @@ describe('the wind-down retry with a message queued (P2-31)', () => {
       stopAgent,
       stopStartingAgent: stopAgent,
       closeConversation: vi.fn(async () => false),
-      onError: (_id, error) => {
-        throw error
+      // A failed step fails the test.
+      logger: {
+        warn: (_message, fields) => {
+          throw fields.error
+        },
+        error: (_message, fields) => {
+          throw fields.error
+        }
       }
     })
     await sweep.tick()
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-conversation-lifetime.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-conversation-lifetime.ts
index 1980616f176..491021dc1c1 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-conversation-lifetime.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-conversation-lifetime.ts
@@ -24,6 +24,7 @@ import type { StructuredAgentSessionHostSession } from './structured-agent-sessi
 import { StructuredAgentSessionIdleSweep } from './structured-agent-session-idle-sweep'
 import { AGENT_SESSION_NOT_ATTACHED } from './structured-agent-session-mutation-admission'
 import { adapterSupportsRecord } from './structured-agent-session-provider-support'
+import { deferredStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 export type StructuredAgentSessionConversationLifetime = ReturnType<
   typeof createStructuredAgentSessionConversationLifetime
@@ -45,7 +46,9 @@ export function createStructuredAgentSessionConversationLifetime(host: {
   let disposed = false
   const { sessions, serialize } = host
   const deps = () => host.context().deps
-  const readRefusals = createJournalOpenReadRefusals()
+  const readRefusals = createJournalOpenReadRefusals(
+    deferredStructuredAgentSessionLogger(() => deps().logger)
+  )
   // The owed copy fails as an open does: the reader gets the classified refusal, never its text.
   const whenImported = (sessionId: string, session: StructuredAgentSessionHostSession) =>
     session.journal.whenImported().catch((error: unknown) => {
@@ -88,7 +91,7 @@ export function createStructuredAgentSessionConversationLifetime(host: {
         cause: 'host-stop'
       }),
     closeConversation,
-    onError: (sessionId, error) => deps().onEventSinkError?.({ sessionId, error }),
+    logger: deps().logger,
     ...deps().idleSweep
   })
 
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-conversation-open.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-conversation-open.ts
index ec938f17f13..73285ee1de4 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-conversation-open.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-conversation-open.ts
@@ -38,7 +38,7 @@ export type StructuredAgentSessionConversationOpenDeps = {
   store: Pick<AgentSessionRecordStore, 'getRecord'>
   adapter: Pick<StructuredAgentSessionAdapter, 'historyFilePath'>
   journalDatabase: JournalHostDatabase
-  onEventSinkError?: StructuredAgentSessionHostDeps['onEventSinkError']
+  logger: StructuredAgentSessionHostDeps['logger']
 }
 
 /** An acquisition's own open: its reserve cleared the record's death evidence, so it settles
@@ -104,7 +104,11 @@ export async function openStructuredAgentSessionConversationJournal(
     // one is only doubt, which provider history decides under a won lease.
     await opened.journal.markPendingSubmissionsUnknown(fence)
   } catch (error) {
-    deps.onEventSinkError?.({ sessionId, error })
+    deps.logger.warn('marking pending sends unknown on open failed', {
+      scope: 'open-pending-unknown',
+      sessionId,
+      error
+    })
   }
   // No child in this process writes to a journal nobody had open, so whatever it shows running
   // belongs to a generation that is gone, whatever the lease still claims. Settled before any
@@ -135,7 +139,7 @@ export async function resettleOpenStructuredAgentSessionConversation(
 }
 
 async function settleGoneGeneration(
-  deps: Pick<StructuredAgentSessionConversationOpenDeps, 'onEventSinkError'>,
+  deps: Pick<StructuredAgentSessionConversationOpenDeps, 'logger'>,
   record: AgentSessionRecord,
   journal: AgentSessionJournal
 ): Promise<void> {
@@ -150,7 +154,11 @@ async function settleGoneGeneration(
     })
   } catch (error) {
     // Best effort: the next open or acquire re-derives it.
-    deps.onEventSinkError?.({ sessionId: record.sessionId, error })
+    deps.logger.warn("settling a gone agent's work on open failed", {
+      scope: 'open-dead-generation',
+      sessionId: record.sessionId,
+      error
+    })
   }
 }
 
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-conversation-stop.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-conversation-stop.test.ts
index 55f58d06a59..0f7c471ed0a 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-conversation-stop.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-conversation-stop.test.ts
@@ -26,6 +26,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 
@@ -55,6 +56,7 @@ beforeEach(async () => {
   stopEndsSession = false
   store = await openTestAgentSessionRecordStore(root)
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: {
       acquire: async ({ fence, spawnToken, events: sink }) => {
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-conversations.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-conversations.test.ts
index 3557594b751..ec4c76e26ba 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-conversations.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-conversations.test.ts
@@ -9,6 +9,7 @@ import { createTrackedJournalOpener } from '../agent-session-journal/journal-hos
 import { StructuredAgentSessionConversations } from './structured-agent-session-conversations'
 import type { StructuredAgentSessionHostSession } from './structured-agent-session-host-types'
 import { hostTestAttachParams } from './structured-agent-session-host-test-data'
+import { recordingStructuredAgentSessionLogger } from './structured-agent-session-logger-test-support'
 
 const IDENTITY: AgentSessionJournalIdentity = {
   sessionId: 'session-1',
@@ -55,7 +56,7 @@ describe('a conversation delivers what its journal commits', () => {
     const deliver = vi.fn()
     const conversations = new StructuredAgentSessionConversations({
       deliver,
-      onDeliveryError: vi.fn(),
+      logger: recordingStructuredAgentSessionLogger().logger,
       now: () => 0
     })
     const journal = await openJournal('a')
@@ -74,7 +75,7 @@ describe('a conversation delivers what its journal commits', () => {
     const sessions: Map<string, StructuredAgentSessionHostSession> =
       new StructuredAgentSessionConversations({
         deliver,
-        onDeliveryError: vi.fn(),
+        logger: recordingStructuredAgentSessionLogger().logger,
         now: () => 0
       })
     const journal = await openJournal('a')
@@ -89,7 +90,7 @@ describe('a conversation delivers what its journal commits', () => {
     const deliver = vi.fn()
     const conversations = new StructuredAgentSessionConversations({
       deliver,
-      onDeliveryError: vi.fn(),
+      logger: recordingStructuredAgentSessionLogger().logger,
       now: () => 0
     })
     const journal = await openJournal('a')
@@ -104,7 +105,7 @@ describe('a conversation delivers what its journal commits', () => {
     const deliver = vi.fn()
     const conversations = new StructuredAgentSessionConversations({
       deliver,
-      onDeliveryError: vi.fn(),
+      logger: recordingStructuredAgentSessionLogger().logger,
       now: () => 0
     })
     const replaced = await openJournal('a')
@@ -123,7 +124,7 @@ describe('a conversation delivers what its journal commits', () => {
     const deliver = vi.fn()
     const conversations = new StructuredAgentSessionConversations({
       deliver,
-      onDeliveryError: vi.fn(),
+      logger: recordingStructuredAgentSessionLogger().logger,
       now: () => 0
     })
     const journal = await openJournal('a')
@@ -137,12 +138,12 @@ describe('a conversation delivers what its journal commits', () => {
 
   it('reports a reader failure without failing the durable write', async () => {
     const failure = new Error('reader failed')
-    const onDeliveryError = vi.fn()
+    const log = recordingStructuredAgentSessionLogger()
     const conversations = new StructuredAgentSessionConversations({
       deliver: () => {
         throw failure
       },
-      onDeliveryError,
+      logger: log.logger,
       now: () => 0
     })
     const journal = await openJournal('a')
@@ -152,7 +153,9 @@ describe('a conversation delivers what its journal commits', () => {
       itemId: expect.any(String)
     })
 
-    expect(onDeliveryError).toHaveBeenCalledExactlyOnceWith('session-1', failure)
+    expect(log.entries.map((entry) => entry.fields)).toEqual([
+      { scope: 'journal-delivery', sessionId: 'session-1', error: failure }
+    ])
     expect(journal.snapshot().items.map((item) => item.body)).toContainEqual({
       kind: 'status',
       text: 'durable'
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-conversations.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-conversations.ts
index 70fe538ce20..b634b74c212 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-conversations.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-conversations.ts
@@ -1,5 +1,6 @@
 import type { AgentSessionJournal } from '../agent-session-journal/journal-store'
 import type { StructuredAgentSessionHostSession } from './structured-agent-session-host-types'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 /**
  * The host's open conversations. A journal handle becomes a conversation's when it is set here,
@@ -22,7 +23,7 @@ export class StructuredAgentSessionConversations extends Map<
   constructor(
     private readonly delivery: {
       deliver: (sessionId: string, journal: AgentSessionJournal) => void
-      onDeliveryError: (sessionId: string, error: unknown) => void
+      logger: StructuredAgentSessionLogger
       /** A conversation became held: state that waited on it (queued drafts) re-derives. */
       onOpened?: (sessionId: string) => void
       now: () => number
@@ -47,7 +48,11 @@ export class StructuredAgentSessionConversations extends Map<
         try {
           this.delivery.deliver(sessionId, journal)
         } catch (error) {
-          this.delivery.onDeliveryError(sessionId, error)
+          this.delivery.logger.warn('delivering a journal commit failed', {
+            scope: 'journal-delivery',
+            sessionId,
+            error
+          })
         }
       })
     })
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-crash-mid-start.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-crash-mid-start.test.ts
index 22295ea6e86..059567386a6 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-crash-mid-start.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-crash-mid-start.test.ts
@@ -25,6 +25,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 const CHILD_PID = 4321
@@ -92,6 +93,7 @@ function host(
   overrides: Partial<StructuredAgentSessionHostDeps> = {}
 ): StructuredAgentSessionHost {
   return new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter,
     journalDatabase: openTestJournalHostDatabase(generationRoot(generation)),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-crash-turn-end.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-crash-turn-end.test.ts
index 9d396b58ffa..7e237615089 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-crash-turn-end.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-crash-turn-end.test.ts
@@ -45,6 +45,8 @@ import {
   HOST_TEST_LOCATION as LOCATION,
   HOST_TEST_SESSION as SESSION
 } from './structured-agent-session-host-test-data'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
+import { recordingStructuredAgentSessionLogger } from './structured-agent-session-logger-test-support'
 
 const PROVIDER_SESSION = 'provider-session-alpha-1'
 /** The tool call's row: the last thing the provider wrote before the crash. */
@@ -155,6 +157,7 @@ async function seedClaudeToolTurn(): Promise<void> {
 
 function openHost(overrides: Partial<StructuredAgentSessionHostDeps>): void {
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: {
       acquire: vi.fn(),
@@ -440,11 +443,11 @@ describe('a turn a read reached before the reconcile proved its owner dead', ()
 
   it('stays unverifiable when the revision cannot be written, and a later open revises it', async () => {
     let now = RELAUNCHED_AT
-    const onEventSinkError = vi.fn()
+    const log = recordingStructuredAgentSessionLogger()
     openHost({
       probeOwner: async () => ({ outcome: 'pid-absent' }),
       now: () => now,
-      onEventSinkError
+      logger: log.logger
     })
     await host.history({ sessionId: SESSION, direction: 'tail' })
     const { journal } = host.collaboratorsForTests().sessions.get(SESSION)!
@@ -453,7 +456,7 @@ describe('a turn a read reached before the reconcile proved its owner dead', ()
     await host.reconcileRestartLeases()
     await drainSession()
 
-    expect(onEventSinkError).toHaveBeenCalledOnce()
+    expect(log.scopes()).toEqual(['open-dead-generation'])
     expect(await settledTurn()).toEqual(UNVERIFIABLE_TURN)
     // The proof is durable on the record, so the next open converges.
     now += STRUCTURED_AGENT_SESSION_IDLE_MS + 1
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-dead-generation-settlement.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-dead-generation-settlement.test.ts
index 6677a50b447..b39790e6b2a 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-dead-generation-settlement.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-dead-generation-settlement.test.ts
@@ -100,7 +100,7 @@ describe('dead structured-session generation settlement', () => {
         verdict: { state: 'unverifiable' },
         showUnexpectedExitOutcome: false
       })
-    ).resolves.toBe(true)
+    ).resolves.toEqual({ ok: true })
 
     const snapshot = journal.snapshot()
     expect(snapshot.submissions).toEqual([
@@ -135,9 +135,9 @@ describe('dead structured-session generation settlement', () => {
       showUnexpectedExitOutcome: true
     }
 
-    await expect(settleStructuredAgentSessionDeadGeneration(input)).resolves.toBe(true)
+    await expect(settleStructuredAgentSessionDeadGeneration(input)).resolves.toEqual({ ok: true })
     const settledCursor = journal.cursor()
-    await expect(settleStructuredAgentSessionDeadGeneration(input)).resolves.toBe(true)
+    await expect(settleStructuredAgentSessionDeadGeneration(input)).resolves.toEqual({ ok: true })
 
     expect(journal.cursor()).toEqual(settledCursor)
     expect(
@@ -166,7 +166,7 @@ describe('dead structured-session generation settlement', () => {
           detail: providerDiagnostic('stack frame '.repeat(4_000), 'log')
         })
       })
-    ).resolves.toBe(true)
+    ).resolves.toEqual({ ok: true })
 
     const statuses = journal
       .snapshot()
@@ -258,7 +258,7 @@ describe('dead structured-session generation settlement', () => {
         verdict: { state: 'interrupted', completedAt: 1_000 },
         showUnexpectedExitOutcome: false
       })
-    ).resolves.toBe(true)
+    ).resolves.toEqual({ ok: true })
   })
 
   it('settles a live unknown submission even when no unfinished item remains', async () => {
@@ -285,7 +285,7 @@ describe('dead structured-session generation settlement', () => {
         verdict: { state: 'interrupted', completedAt: 1_000 },
         showUnexpectedExitOutcome: false
       })
-    ).resolves.toBe(true)
+    ).resolves.toEqual({ ok: true })
 
     expect(journal.submissions()).toEqual([
       expect.objectContaining({
@@ -463,7 +463,7 @@ describe('whether a dead generation interrupted anything', () => {
           1_000
         )
       })
-    ).resolves.toBe(true)
+    ).resolves.toEqual({ ok: true })
 
     const snapshot = journal.snapshot()
     expect(snapshot.items.some((item) => item.body.kind === 'status')).toBe(false)
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-dead-generation-settlement.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-dead-generation-settlement.ts
index 72caac40844..8ec0768cc52 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-dead-generation-settlement.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-dead-generation-settlement.ts
@@ -102,6 +102,11 @@ export function unfinishedStructuredAgentSessionWorkWasInterrupted(
   return outcomeItems.some((item) => !isCleanlySettled(currentItems.get(item.itemId)))
 }
 
+/** Whether the settlement was written, and what stopped it when it was not. */
+export type StructuredAgentSessionDeadGenerationSettlement =
+  | { ok: true }
+  | { ok: false; error: unknown }
+
 export async function settleStructuredAgentSessionDeadGeneration(input: {
   journal: DeadGenerationJournal
   sessionId: string
@@ -117,13 +122,12 @@ export async function settleStructuredAgentSessionDeadGeneration(input: {
   /** The provider never finished starting: the start that failed, keyed by the child's
    *  generation. Its row is the one the delivery loop writes for the same start. */
   exitedDuringStartup?: { generation: string | null }
-  onError?: (sessionId: string, error: unknown) => void
-}): Promise<boolean> {
+}): Promise<StructuredAgentSessionDeadGenerationSettlement> {
   try {
     const hasUnfinishedWork = hasUnfinishedStructuredAgentSessionWork(input.journal)
     const showUnexpectedExitOutcome = input.showUnexpectedExitOutcome ?? hasUnfinishedWork
     if (!showUnexpectedExitOutcome && !hasUnfinishedWork) {
-      return true
+      return { ok: true }
     }
     // A queued message is the delivery loop's to settle: it was never handed to this child. A
     // child that never proved its start accepted nothing either — input is written only after it
@@ -189,10 +193,10 @@ export async function settleStructuredAgentSessionDeadGeneration(input: {
         mutations: chunk.mutations
       })
     }
-    return true
+    return { ok: true }
   } catch (error) {
-    input.onError?.(input.sessionId, error)
-    return false
+    // Returned rather than logged: each caller logs it under its own scope.
+    return { ok: false, error }
   }
 }
 
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-delivery-loop.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-delivery-loop.ts
index ad149dbf947..3727040e3c0 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-delivery-loop.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-delivery-loop.ts
@@ -40,6 +40,7 @@ import {
 import { failedProviderChildStart } from './structured-agent-session-provider-child'
 import { handOverSubmission } from './structured-agent-session-turns'
 import { structuredAgentSessionCommandRunning } from './structured-agent-session-command-turn'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 export type StructuredAgentSessionDeliveryLoopDeps = {
   sessions: ReadonlyMap<string, StructuredAgentSessionHostSession>
@@ -62,7 +63,7 @@ export type StructuredAgentSessionDeliveryLoopDeps = {
   ) => Promise<boolean>
   /** Who the chat's failure sentences name. */
   failureTextContext: (sessionId: string) => AgentSessionFailureWordsContext
-  onError: (sessionId: string, error: unknown) => void
+  logger: StructuredAgentSessionLogger
   record: (sessionId: string) => AgentSessionRecord | null
   readChildWork: (sessionId: string) => readonly AgentChildWorkView[] | undefined
   flushStreamedEvents: (sessionId: string) => Promise<void>
@@ -139,14 +140,22 @@ export class StructuredAgentSessionDeliveryLoop {
       }
     } catch (error) {
       // The error is Orca's own and goes to the log; the chat says only that Orca failed.
-      this.deps.onError(sessionId, error)
+      this.deps.logger.warn('delivering a queued message failed', {
+        scope: 'delivery-loop',
+        sessionId,
+        error
+      })
       const cause = { hostFault: true } as const
       await this.deps
         .serialize(sessionId, () => this.fail(sessionId, { startKey: null, cause }))
         .catch((failure: unknown) => {
           // Rows left queued are rejected by the next open, or by the next loop an accept wakes.
           this.running.delete(sessionId)
-          this.deps.onError(sessionId, failure)
+          this.deps.logger.warn('recording a failed delivery failed', {
+            scope: 'delivery-loop-fail',
+            sessionId,
+            error: failure
+          })
         })
     }
   }
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-event-recovery.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-event-recovery.ts
index 56a0acf853d..2b9340859f4 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-event-recovery.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-event-recovery.ts
@@ -22,10 +22,13 @@ export class StructuredAgentSessionEventRecovery {
       publishStatus?: (sessionId: string) => void
       serialize: <T>(sessionId: string, task: () => Promise<T>) => Promise<T>
       now: () => number
-      onBarrierError: (sessionId: string, error: unknown) => void
     }
   ) {}
 
+  private get exitContext() {
+    return { ...this.context, logger: this.context.deps.logger }
+  }
+
   recoverAfterSinkFailure(sessionId: string, error: unknown): void {
     if (this.sinkFailures.has(sessionId)) {
       return
@@ -56,7 +59,16 @@ export class StructuredAgentSessionEventRecovery {
         } as const
       })
       .then((event) => (event ? this.handle(event) : undefined))
-      .catch((recoveryError) => this.context.onBarrierError(sessionId, recoveryError))
+      .catch((error: unknown) =>
+        this.context.deps.logger.warn(
+          'stopping a provider after its journal failed did not finish',
+          {
+            scope: 'sink-failure-recovery',
+            sessionId,
+            error
+          }
+        )
+      )
       .finally(() => this.sinkFailures.delete(sessionId))
   }
 
@@ -66,6 +78,6 @@ export class StructuredAgentSessionEventRecovery {
     if (event.type === 'started') {
       return settleStructuredAgentSessionProviderStarted(this.context, event)
     }
-    await settleUnexpectedStructuredAgentSessionExit(this.context, event)
+    await settleUnexpectedStructuredAgentSessionExit(this.exitContext, event)
   }
 }
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-event-sink-queue.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-event-sink-queue.ts
index 2d0766a4bce..508893d67f4 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-event-sink-queue.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-event-sink-queue.ts
@@ -45,7 +45,8 @@ export class StructuredAgentSessionSinkQueue {
   constructor(
     private readonly deps: {
       watermarks: StructuredAgentSessionSinkWatermarks
-      onError?: (error: unknown) => void
+      /** The queue just failed for good; it accepts and runs nothing more. */
+      onFailed?: (error: unknown) => void
       readingControl?: StructuredAgentSessionReadingControl
       onBackpressureChange?: (
         backpressured: boolean,
@@ -212,7 +213,7 @@ export class StructuredAgentSessionSinkQueue {
   private fail = (error: unknown): void => {
     if (this.failure === null) {
       this.failure = { error }
-      this.deps.onError?.(error)
+      this.deps.onFailed?.(error)
     }
     this.queue.length = 0
     this.queuedBytes = 0
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-event-sink.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-event-sink.test.ts
index 46dc8fbf7e4..2993ce35a4e 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-event-sink.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-event-sink.test.ts
@@ -15,6 +15,8 @@ import {
   type StructuredAgentSessionEventTarget
 } from './structured-agent-session-event-sink'
 import { StructuredAgentSessionHostRuntimeState } from './structured-agent-session-host-runtime-state'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
+import { testEventSinkLogging } from './structured-agent-session-logger-test-support'
 
 const BODY: AgentJournalItemBody = {
   kind: 'message',
@@ -91,7 +93,7 @@ function target(
 describe('deferred structured agent-session event sink', () => {
   it('buffers writes made before the journal exists and drains them in arrival order', async () => {
     const log: Recorded[] = []
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
 
     deferred.sink.appendItem(identity(0), BODY, { turnScope: AGENT_JOURNAL_THREAD_SCOPE })
     deferred.sink.appendItem(identity(1), BODY, { turnScope: AGENT_JOURNAL_THREAD_SCOPE })
@@ -110,7 +112,7 @@ describe('deferred structured agent-session event sink', () => {
 
   it('writes at the fence bound at submission time, so a rebind cannot backdate a write', async () => {
     const log: Recorded[] = []
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
     deferred.bind(target(1, log))
 
     deferred.sink.appendItem(identity(0), BODY, { turnScope: AGENT_JOURNAL_THREAD_SCOPE })
@@ -127,7 +129,7 @@ describe('deferred structured agent-session event sink', () => {
 
   it('buffers replacement-acquisition events while unbound', async () => {
     const log: Recorded[] = []
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
     deferred.bind(target(1, log))
     deferred.unbind()
 
@@ -141,7 +143,7 @@ describe('deferred structured agent-session event sink', () => {
 
   it('resolves a lifecycle transition after journal bind and skips an existing state', async () => {
     const log: Recorded[] = []
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
 
     expect(
       deferred.sink.tryAppendLifecycleTransition?.(identity(0), BODY, () => identity(1), {
@@ -166,7 +168,7 @@ describe('deferred structured agent-session event sink', () => {
 
   it('drops buffered and later writes once closed, and refuses to rebind', async () => {
     const log: Recorded[] = []
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
 
     deferred.sink.appendItem(identity(0), BODY, { turnScope: AGENT_JOURNAL_THREAD_SCOPE })
     deferred.close()
@@ -182,7 +184,8 @@ describe('deferred structured agent-session event sink', () => {
     const errors: unknown[] = []
     const readingControl = { pauseReading: vi.fn(), resumeReading: vi.fn() }
     const deferred = createDeferredStructuredAgentSessionEventSink({
-      onError: (error) => errors.push(error),
+      ...testEventSinkLogging(),
+      onFailed: (error) => errors.push(error),
       readingControl
     })
     deferred.bind(target(4, log, 0))
@@ -206,7 +209,11 @@ describe('deferred structured agent-session event sink', () => {
   })
 
   it('replaces a failed cached sink before recovery drain', async () => {
-    const runtime = new StructuredAgentSessionHostRuntimeState({ store: {} } as never)
+    // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: the cached-sink path reads only the logger, on the failed drain.
+    const runtime = new StructuredAgentSessionHostRuntimeState({
+      store: {},
+      logger: createStructuredAgentSessionLogger()
+    } as never)
     const failed = runtime.eventSinkFor('session-1')
     failed.bind(target(1, [], 0))
     failed.sink.appendItem(identity(0), BODY, { turnScope: AGENT_JOURNAL_THREAD_SCOPE })
@@ -226,6 +233,7 @@ describe('deferred structured agent-session event sink', () => {
     const changes: boolean[] = []
     const readingControl = { pauseReading: vi.fn(), resumeReading: vi.fn() }
     const deferred = createDeferredStructuredAgentSessionEventSink({
+      ...testEventSinkLogging(),
       watermarks: {
         maxQueuedBytes: 1_000_000,
         lowQueuedBytes: 0,
@@ -262,6 +270,7 @@ describe('deferred structured agent-session event sink', () => {
   it('admits a resolved append and publication as one bounded operation', async () => {
     const log: Recorded[] = []
     const deferred = createDeferredStructuredAgentSessionEventSink({
+      ...testEventSinkLogging(),
       watermarks: {
         pauseQueuedOperations: 1,
         maxQueuedOperations: 2,
@@ -299,6 +308,7 @@ describe('deferred structured agent-session event sink', () => {
     const changes: boolean[] = []
     const readingControl = { pauseReading: vi.fn(), resumeReading: vi.fn() }
     const deferred = createDeferredStructuredAgentSessionEventSink({
+      ...testEventSinkLogging(),
       watermarks: {
         pauseQueuedBytes: 1,
         maxQueuedBytes: 1_000_000,
@@ -329,7 +339,8 @@ describe('deferred structured agent-session event sink', () => {
     const log: Recorded[] = []
     const errors: unknown[] = []
     const deferred = createDeferredStructuredAgentSessionEventSink({
-      onError: (error) => errors.push(error),
+      ...testEventSinkLogging(),
+      onFailed: (error) => errors.push(error),
       watermarks: {
         pauseQueuedBytes: 1,
         maxQueuedBytes: 1,
@@ -364,6 +375,7 @@ describe('deferred structured agent-session event sink', () => {
     const firstControl = { pauseReading: vi.fn(), resumeReading: vi.fn() }
     const secondControl = { pauseReading: vi.fn(), resumeReading: vi.fn() }
     const deferred = createDeferredStructuredAgentSessionEventSink({
+      ...testEventSinkLogging(),
       watermarks: {
         pauseQueuedBytes: 1,
         maxQueuedBytes: 1_000_000,
@@ -395,7 +407,7 @@ describe('deferred structured agent-session event sink', () => {
 
   it('replaces a queued same-item checkpoint before it runs', async () => {
     const log: Recorded[] = []
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
     const options = { coalescingKey: 'checkpoint:item-1', turnScope: AGENT_JOURNAL_THREAD_SCOPE }
 
     deferred.sink.appendItem(identity(0), BODY, options)
@@ -411,7 +423,7 @@ describe('deferred structured agent-session event sink', () => {
     // The journal applies a settlement id once and skips any later batch with it,
     // so the queue must not let a later batch replace one it has not run yet.
     const log: Recorded[] = []
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
     const batch = (ordinal: number) => [
       {
         kind: 'item' as const,
@@ -440,7 +452,7 @@ describe('deferred structured agent-session event sink', () => {
 
   it('keeps a replacement checkpoint after distinct intervening operations', async () => {
     const log: Recorded[] = []
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
     const options = { coalescingKey: 'checkpoint:item-1', turnScope: AGENT_JOURNAL_THREAD_SCOPE }
 
     deferred.sink.appendItem(identity(0), BODY, options)
@@ -457,7 +469,7 @@ describe('deferred structured agent-session event sink', () => {
 
   it('coalesces provider activity as a publication without a journal write', async () => {
     const log: Recorded[] = []
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
 
     deferred.sink.setActivity?.({ turnId: 'turn-1', text: 'Thinking' })
     deferred.sink.setActivity?.({ turnId: 'turn-1', text: 'Checking the result' })
@@ -486,7 +498,7 @@ describe('producer linkage reaches the journal through every append path', () =>
   it('forwards the whole bundle on the plain and try append paths', async () => {
     for (const append of ['appendItem', 'tryAppendItem'] as const) {
       const log: Recorded[] = []
-      const deferred = createDeferredStructuredAgentSessionEventSink()
+      const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
       deferred.bind(target(5, log))
       deferred.sink[append]?.(identity(1), BODY, {
         ...LINKAGE,
@@ -510,7 +522,7 @@ describe('producer linkage reaches the journal through every append path', () =>
       'tryAppendLifecycleTransition'
     ] as const) {
       const log: Recorded[] = []
-      const deferred = createDeferredStructuredAgentSessionEventSink()
+      const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
       deferred.bind(target(5, log))
       deferred.sink[append]?.(identity(1), BODY, () => identity(1), {
         ...LINKAGE,
@@ -530,7 +542,7 @@ describe('producer linkage reaches the journal through every append path', () =>
     // would stamp whoever opened the batch onto all of them. Both callers are
     // single-producer today; a mixed batch would have to stamp per mutation.
     const log: Recorded[] = []
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
     deferred.bind(target(5, log))
     deferred.sink.appendLifecycleBatch?.(
       'settle-1',
@@ -547,7 +559,7 @@ describe('producer linkage reaches the journal through every append path', () =>
 
   it("writes no linkage keys at all for the session's own agent", async () => {
     const log: Recorded[] = []
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
     deferred.bind(target(5, log))
     deferred.sink.appendItem(identity(1), BODY, { turnScope: AGENT_JOURNAL_THREAD_SCOPE })
     await deferred.drained()
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-event-sink.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-event-sink.ts
index 121fb865db4..18003e72369 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-event-sink.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-event-sink.ts
@@ -12,6 +12,7 @@ import { estimateStructuredAgentSessionItemBytes } from './structured-agent-sess
 import { StructuredAgentSessionSinkQueue } from './structured-agent-session-event-sink-queue'
 import { structuredAgentSessionJournalAppendOptions } from './structured-agent-session-journal-append-options'
 import { createStructuredAgentSessionResolvedAppend } from './structured-agent-session-resolved-append'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 export type StructuredAgentSessionSinkAdmission =
   | { accepted: true }
@@ -193,18 +194,28 @@ const DEFAULT_WATERMARKS: StructuredAgentSessionSinkWatermarks = {
   maxLifecycleQueuedOperations: 1_024
 }
 
-export function createDeferredStructuredAgentSessionEventSink(
-  deps: {
-    onError?: (error: unknown) => void
-    watermarks?: Partial<StructuredAgentSessionSinkWatermarks>
-    readingControl?: StructuredAgentSessionReadingControl
-    onBackpressureChange?: (backpressured: boolean, state: StructuredAgentSessionSinkState) => void
-  } = {}
-): DeferredStructuredAgentSessionEventSink {
+export function createDeferredStructuredAgentSessionEventSink(deps: {
+  /** The session this sink writes for, named in every failure it logs. */
+  sessionId: string
+  logger: StructuredAgentSessionLogger
+  /** The sink failed for good; the owner decides what that costs the provider. */
+  onFailed?: (error: unknown) => void
+  watermarks?: Partial<StructuredAgentSessionSinkWatermarks>
+  readingControl?: StructuredAgentSessionReadingControl
+  onBackpressureChange?: (backpressured: boolean, state: StructuredAgentSessionSinkState) => void
+}): DeferredStructuredAgentSessionEventSink {
   const watermarks = { ...DEFAULT_WATERMARKS, ...deps.watermarks }
+  const failed = (error: unknown): void => {
+    deps.logger.error('writing provider events to the chat journal failed', {
+      scope: 'journal-event-sink',
+      sessionId: deps.sessionId,
+      error
+    })
+    deps.onFailed?.(error)
+  }
   const queue = new StructuredAgentSessionSinkQueue({
     watermarks,
-    ...(deps.onError ? { onError: deps.onError } : {}),
+    onFailed: failed,
     ...(deps.readingControl ? { readingControl: deps.readingControl } : {}),
     ...(deps.onBackpressureChange ? { onBackpressureChange: deps.onBackpressureChange } : {})
   })
@@ -280,7 +291,7 @@ export function createDeferredStructuredAgentSessionEventSink(
       appendLifecycleBatch: (settlementId, mutations, options = {}) => {
         const admission = appendLifecycleBatch(settlementId, mutations, options)
         if (!admission.accepted) {
-          deps.onError?.(
+          failed(
             new Error(
               `lifecycle journal batch ${settlementId} rejected by sink ${admission.reason}`
             )
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-eviction.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-eviction.test.ts
index 38349f95115..236dc7bc54b 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-eviction.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-eviction.test.ts
@@ -10,12 +10,15 @@ import {
   AgentSessionPreSpawnError
 } from './structured-agent-session-adapter'
 import { StructuredAgentSessionHostRuntimeState } from './structured-agent-session-host-runtime-state'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
+import { recordingStructuredAgentSessionLogger } from './structured-agent-session-logger-test-support'
 
 function context(): StructuredAgentSessionEvictionContext & { order: string[] } {
   const order: string[] = []
   return {
     order,
     sessionId: 'session-1',
+    logger: createStructuredAgentSessionLogger(),
     eventSink: {
       unbind: vi.fn(() => order.push('unbind')),
       drained: vi.fn(async () => {
@@ -44,9 +47,11 @@ function context(): StructuredAgentSessionEvictionContext & { order: string[] }
 }
 
 function runtimeState(): StructuredAgentSessionHostRuntimeState {
+  // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: eviction against the sink cache reads only the sinks and the logger; store and adapter are never reached.
   return new StructuredAgentSessionHostRuntimeState({
-    store: {} as never,
-    adapter: {} as never
+    store: {},
+    adapter: {},
+    logger: recordingStructuredAgentSessionLogger().logger
   } as never)
 }
 
@@ -146,6 +151,7 @@ describe('rows the provider emits while closing', () => {
 
     await evictStructuredAgentSession({
       sessionId,
+      logger: recordingStructuredAgentSessionLogger().logger,
       eventSink: sink,
       adapter: {
         closeSession: async () => {
@@ -227,6 +233,7 @@ describe('eviction against the real sink cache', () => {
     const sessionId = 'session-reattach'
     await evictStructuredAgentSession({
       sessionId,
+      logger: recordingStructuredAgentSessionLogger().logger,
       eventSink: state.eventSinkFor(sessionId),
       adapter: { closeSession: async () => true } as never,
       discardSink: () => state.discardEventSink(sessionId),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-eviction.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-eviction.ts
index 182d2e70192..7dde43d165d 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-eviction.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-eviction.ts
@@ -25,6 +25,7 @@ import { stopAgentSessionProviderRoot } from './structured-agent-session-provide
 import type { DeferredStructuredAgentSessionEventSink } from './structured-agent-session-event-sink'
 import type { StructuredAgentSessionStopVerdict } from './structured-agent-session-host-types'
 import { withTimeout } from '../../../shared/promise-timeout-fallback'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 export type StructuredAgentSessionEvictionContext = {
   sessionId: string
@@ -33,6 +34,7 @@ export type StructuredAgentSessionEvictionContext = {
   hasProviderChild?: boolean
   eventSink: DeferredStructuredAgentSessionEventSink
   adapter: StructuredAgentSessionAdapter
+  logger: StructuredAgentSessionLogger
   /** Tells the adapter the released lease is done with, so it drops this child's route and index.
    *  The conversation stays: stopping the agent never closes its journal. */
   acknowledgeRelease: () => Promise<void> | void
@@ -76,7 +78,10 @@ export const STRUCTURED_AGENT_SESSION_EVICTION_STEPS: readonly StructuredAgentSe
         try {
           context.beforeProviderChildStop()
         } catch {
-          console.warn('[structured-agent-session] capturing recovery witness failed')
+          context.logger.warn('capturing a recovery witness before a stop failed', {
+            scope: 'recovery-witness',
+            sessionId: context.sessionId
+          })
         }
       }
     },
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-failed-create-owner-verdict.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-failed-create-owner-verdict.test.ts
index d1a45fc469a..fca04e1028a 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-failed-create-owner-verdict.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-failed-create-owner-verdict.test.ts
@@ -23,6 +23,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 const EXIT_REASON = 'claude stream-json exited (code 1): stderr tail'
@@ -51,6 +52,7 @@ beforeEach(async () => {
   }))
   store = await openTestAgentSessionRecordStore(root)
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: {
       acquire,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-failed-create-sink-release.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-failed-create-sink-release.test.ts
index 06538d78310..38b85ca12d1 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-failed-create-sink-release.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-failed-create-sink-release.test.ts
@@ -21,6 +21,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 const EXIT_REASON = 'claude stream-json exited (code 1): claude: not signed in'
@@ -47,6 +48,7 @@ beforeEach(async () => {
   }))
   store = await openTestAgentSessionRecordStore(root)
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: {
       acquire,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-forget-status.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-forget-status.test.ts
index fdaa5b72d50..c0e78b5a0c5 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-forget-status.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-forget-status.test.ts
@@ -24,6 +24,7 @@ import { attachStructuredAgentSession } from './structured-agent-session-attach-
 import type { StructuredAgentSessionAttachContext } from './structured-agent-session-attach-context'
 import type { StructuredAgentSessionHostSession } from './structured-agent-session-host-types'
 import { StructuredAgentSessionStatusFeed } from './structured-agent-session-status-feed'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 // Everything before the journal is out of scope here; what matters is what the orchestration does
 // when the attach throws after acquisition.
@@ -146,6 +147,7 @@ async function workingSession(): Promise<{
   const server = new AgentHookServer()
   const records = new Map([[SESSION, ownerRecord()]])
   const feed = new StructuredAgentSessionStatusFeed({
+    logger: createStructuredAgentSessionLogger(),
     sessions,
     getRecord: (sessionId) => records.get(sessionId) ?? null,
     now: () => 1,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-grouped-prompt.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-grouped-prompt.test.ts
index b18279392b9..b82499c2830 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-grouped-prompt.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-grouped-prompt.test.ts
@@ -24,6 +24,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 
@@ -133,6 +134,7 @@ beforeEach(async () => {
   answerPrompt = vi.fn(async ({ commit }) => commit())
   store = await openTestAgentSessionRecordStore(root)
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: adapter(),
     journalDatabase: openTestJournalHostDatabase(root),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-host-delivery.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-host-delivery.ts
index 5d8a4d0429b..f2f885e0763 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-host-delivery.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-host-delivery.ts
@@ -78,7 +78,7 @@ export function createStructuredAgentSessionConversationDelivery(input: {
         deps.store.getRecord(sessionId),
         sessions.get(sessionId)?.journal
       ),
-    onError: (sessionId, error) => deps.onEventSinkError?.({ sessionId, error }),
+    logger: deps.logger,
     record: (sessionId) => deps.store.getRecord(sessionId),
     readChildWork: input.clientDelivery.readChildWork,
     flushStreamedEvents: input.flushStreamedEvents,
@@ -116,7 +116,11 @@ export function createStructuredAgentSessionConversationDelivery(input: {
       })
       .catch((error: unknown) => {
         wakesQueued.delete(sessionId)
-        deps.onEventSinkError?.({ sessionId, error })
+        deps.logger.warn('waking the delivery loop after a commit failed', {
+          scope: 'delivery-wake',
+          sessionId,
+          error
+        })
       })
   }
   // A chat open before its owner's death was proven revises what its open settled. Queued, never
@@ -129,7 +133,13 @@ export function createStructuredAgentSessionConversationDelivery(input: {
             resettleOpenStructuredAgentSessionConversation(deps, sessionId, sessions.get(sessionId))
           )
         )
-        .catch((error: unknown) => deps.onEventSinkError?.({ sessionId, error }))
+        .catch((error: unknown) =>
+          deps.logger.warn('resettling an open chat after its owner died failed', {
+            scope: 'death-evidence-resettle',
+            sessionId,
+            error
+          })
+        )
     }
   })
   return {
@@ -158,8 +168,12 @@ async function settleInterruptedCommands(
 ): Promise<void> {
   const fence = structuredAgentSessionConversationFence(deps.store, sessionId)
   try {
-    await recoverStructuredRewind(deps.store, sessionId, session.journal, fence)
+    await recoverStructuredRewind(deps, sessionId, session.journal, fence)
   } catch (error) {
-    deps.onEventSinkError?.({ sessionId, error })
+    deps.logger.warn('settling an interrupted rewind on open failed', {
+      scope: 'rewind-recovery',
+      sessionId,
+      error
+    })
   }
 }
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-host-lifetime.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-host-lifetime.ts
index 719540da5da..a2f38c2e6bb 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-host-lifetime.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-host-lifetime.ts
@@ -47,7 +47,7 @@ export type StructuredAgentSessionLifetimeContext = {
   }
 }
 
-type ConversationCloseDeps = Pick<StructuredAgentSessionHostDeps, 'onEventSinkError'> & {
+type ConversationCloseDeps = Pick<StructuredAgentSessionHostDeps, 'logger'> & {
   store: Pick<StructuredAgentSessionHostDeps['store'], 'getRecord'>
 }
 
@@ -70,7 +70,11 @@ export async function abandonQueuedStructuredAgentSessionMessages(
     .then(
       () => true,
       (error: unknown) => {
-        deps.onEventSinkError?.({ sessionId, error })
+        deps.logger.warn('rejecting queued messages of a closed chat failed', {
+          scope: 'queued-abandon',
+          sessionId,
+          error
+        })
         return false
       }
     )
@@ -113,7 +117,6 @@ export async function stopStructuredAgentSessionAgentUnderSerialize(
   const owed = owedProviderChildWindDown(session)
   session.owesProviderChildWindDown = owed ? { ...owed, cause } : undefined
   const stopping = session.child
-  let settlementError: unknown
   const eviction: StructuredAgentSessionEvictionContext = {
     sessionId,
     // The retry must not re-stop a child the adapter already proved gone, so this stays honest.
@@ -121,6 +124,7 @@ export async function stopStructuredAgentSessionAgentUnderSerialize(
     owesProviderChildWindDown: owed !== undefined,
     eventSink: context.runtimeState.eventSinkFor(sessionId),
     adapter: context.deps.adapter,
+    logger: context.deps.logger,
     // The adapter settles its own open turn with this, so who asked travels with the stop.
     stopCause: cause,
     ...(context.restartWitness
@@ -153,15 +157,16 @@ export async function stopStructuredAgentSessionAgentUnderSerialize(
         pendingSubmissionReason: 'provider_closed_before_acknowledgement',
         // Only a turn no adapter settled: one with no close, or whose settle threw.
         verdict: turnVerdictForChildEnd(cause, context.now()),
-        showUnexpectedExitOutcome: false,
-        onError: (id, error) => {
-          settlementError = error
-          context.deps.onEventSinkError?.({ sessionId: id, error })
-        }
+        showUnexpectedExitOutcome: false
       })
-      if (!settled) {
+      if (!settled.ok) {
+        context.deps.logger.warn("settling a closed agent's work failed", {
+          scope: 'close-settlement',
+          sessionId,
+          error: settled.error
+        })
         // Without the cause the log names the step and nothing else.
-        throw new Error('dead generation work settlement failed', { cause: settlementError })
+        throw new Error('dead generation work settlement failed', { cause: settled.error })
       }
     },
     releaseLease: async () => {
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-host-runtime-state.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-host-runtime-state.test.ts
index 5f336345b5e..e8421b02893 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-host-runtime-state.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-host-runtime-state.test.ts
@@ -13,6 +13,8 @@ import {
 } from '../agent-session-journal/journal-host-database-test-support'
 import { StructuredAgentSessionHostRuntimeState } from './structured-agent-session-host-runtime-state'
 import type { StructuredAgentSessionHostDeps } from './structured-agent-session-host'
+import { recordingStructuredAgentSessionLogger } from './structured-agent-session-logger-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const NOW = 1_800_000_000_000
 
@@ -68,7 +70,8 @@ function runtimeState(
     adapter: {},
     journalDatabase: openTestJournalHostDatabase(stateDirectory),
     claimKeyId: 'key-1',
-    probeOwner
+    probeOwner,
+    logger: createStructuredAgentSessionLogger()
   } as StructuredAgentSessionHostDeps
   return new StructuredAgentSessionHostRuntimeState(deps)
 }
@@ -129,7 +132,7 @@ describe('host runtime-state owner probe', () => {
 
   it('does not force-close a provider for transient lease probe errors', async () => {
     const onEventSinkFailure = vi.fn()
-    const onEventSinkError = vi.fn()
+    const log = recordingStructuredAgentSessionLogger()
     const probeOwner = vi.fn(async () => {
       throw new Error('lease probe unavailable')
     })
@@ -144,7 +147,7 @@ describe('host runtime-state owner probe', () => {
       journalDatabase: openTestJournalHostDatabase(stateDirectory),
       claimKeyId: 'key-1',
       probeOwner,
-      onEventSinkError
+      logger: log.logger
     } as unknown as StructuredAgentSessionHostDeps
     const state = new StructuredAgentSessionHostRuntimeState(deps, onEventSinkFailure)
 
@@ -152,10 +155,15 @@ describe('host runtime-state owner probe', () => {
       state as unknown as { leaseRenewer: { renewNow: () => Promise<void> } }
     ).leaseRenewer.renewNow()
 
-    expect(onEventSinkError).toHaveBeenCalledWith({
-      sessionId: record.sessionId,
-      error: expect.any(Error)
-    })
+    expect(log.entries).toContainEqual(
+      expect.objectContaining({
+        fields: expect.objectContaining({
+          scope: 'lease-renewal',
+          sessionId: record.sessionId,
+          error: expect.any(Error)
+        })
+      })
+    )
     expect(onEventSinkFailure).not.toHaveBeenCalled()
   })
 })
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-host-runtime-state.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-host-runtime-state.ts
index 63f37a37590..1df3bc34909 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-host-runtime-state.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-host-runtime-state.ts
@@ -26,7 +26,7 @@ export class StructuredAgentSessionHostRuntimeState {
       now: () => deps.now?.() ?? Date.now(),
       // Lease/ownership failures are transient and stay on the visible lease-error path.
       // Only deferred sink I/O failures are terminal and may force-close a provider.
-      onError: ({ sessionId, error }) => deps.onEventSinkError?.({ sessionId, error })
+      logger: deps.logger
     })
   }
 
@@ -67,8 +67,9 @@ export class StructuredAgentSessionHostRuntimeState {
   mintEventSink(sessionId: string): DeferredStructuredAgentSessionEventSink {
     const minted: DeferredStructuredAgentSessionEventSink =
       createDeferredStructuredAgentSessionEventSink({
-        onError: (error) => {
-          this.deps.onEventSinkError?.({ sessionId, error })
+        sessionId,
+        logger: this.deps.logger,
+        onFailed: (error) => {
           // Only the session's own sink may force its provider down; an attempt's never is.
           if (this.eventSinks.get(sessionId) === minted) {
             this.onEventSinkFailure?.(sessionId, error)
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-host-tabs.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-host-tabs.ts
index 8a18040daf3..5c9f5215a95 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-host-tabs.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-host-tabs.ts
@@ -1,4 +1,5 @@
 import type { AgentSessionRecord } from '../../../shared/agent-session-record'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 /**
  * Chat-tab visibility is the deletion funnel: every path that removes a chat as a user-facing
@@ -9,6 +10,7 @@ import type { AgentSessionRecord } from '../../../shared/agent-session-record'
 export function setStructuredAgentSessionTabVisibility(
   host: {
     deps: {
+      logger: StructuredAgentSessionLogger
       store: {
         setSessionTabVisibility: (
           sessionId: string,
@@ -25,7 +27,10 @@ export function setStructuredAgentSessionTabVisibility(
 ): Promise<void> {
   if (!visible) {
     void host.restartResume.dismiss([sessionId]).catch(() => {
-      console.warn('[structured-agent-session] forgetting recovery records on chat close failed')
+      host.deps.logger.warn('forgetting recovery records on chat close failed', {
+        scope: 'tab-close-recovery-dismiss',
+        sessionId
+      })
     })
   }
   return host.deps.store.setSessionTabVisibility(sessionId, visible, tabId)
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-host-teardown.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-host-teardown.test.ts
index aa8692a0c73..e6f62d6d780 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-host-teardown.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-host-teardown.test.ts
@@ -13,12 +13,15 @@ import {
   RESUME_MARKER_RECORD_TIMEOUT_MS,
   structuredAgentSessionHostTeardownPhases
 } from './structured-agent-session-host-teardown'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
+import { recordingStructuredAgentSessionLogger } from './structured-agent-session-logger-test-support'
 
 const noop = async (): Promise<void> => undefined
 
 describe('structured agent-session host teardown', () => {
   it('names every phase, so the quit-path order is pinned rather than incidental', () => {
     const phases = structuredAgentSessionHostTeardownPhases({
+      logger: createStructuredAgentSessionLogger(),
       idleSweep: { dispose: noop },
       runtimeState: { stopLeaseRenewal: () => undefined, flushAllEventSinks: noop },
       tasks: { drainAttaches: noop },
@@ -62,6 +65,7 @@ describe('structured agent-session host teardown', () => {
   it('ends child eviction as soon as every chat has closed, not at its bound', async () => {
     vi.useFakeTimers({ toFake: ['setTimeout', 'clearTimeout'] })
     const evict = structuredAgentSessionHostTeardownPhases({
+      logger: createStructuredAgentSessionLogger(),
       idleSweep: { dispose: noop },
       runtimeState: { stopLeaseRenewal: () => undefined, flushAllEventSinks: noop },
       tasks: { drainAttaches: noop },
@@ -86,11 +90,12 @@ describe('structured agent-session host teardown', () => {
 
   it('bounds stalled recovery publication without preventing later cleanup', async () => {
     vi.useFakeTimers({ toFake: ['setTimeout', 'clearTimeout'] })
-    const warning = vi.spyOn(console, 'warn').mockImplementation(() => {})
+    const log = recordingStructuredAgentSessionLogger()
     const pending = Promise.withResolvers<void>()
     const cleaned = vi.fn(async () => {})
     const flush = vi.fn(async () => cleaned())
     const phases = structuredAgentSessionHostTeardownPhases({
+      logger: log.logger,
       idleSweep: { dispose: cleaned },
       runtimeState: { stopLeaseRenewal: () => {}, flushAllEventSinks: flush },
       tasks: { drainAttaches: cleaned },
@@ -107,13 +112,10 @@ describe('structured agent-session host teardown', () => {
       await vi.advanceTimersByTimeAsync(2000)
       await teardown
       expect(cleaned).toHaveBeenCalledTimes(4)
-      expect(warning).toHaveBeenCalledWith(
-        '[structured-agent-session] recording recovery capsule failed'
-      )
+      expect(log.scopes()).toEqual(['teardown-recovery-capsule'])
       expect(vi.getTimerCount()).toBe(0)
     } finally {
       pending.resolve()
-      warning.mockRestore()
       vi.useRealTimers()
     }
   })
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-host-teardown.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-host-teardown.ts
index e6700777227..65bf219cf79 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-host-teardown.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-host-teardown.ts
@@ -17,6 +17,7 @@ import {
 } from './structured-agent-session-host-lifetime'
 import { withTimeout } from '../../../shared/promise-timeout-fallback'
 import type { StructuredAgentSessionHostSession } from './structured-agent-session-host-types'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 export type StructuredAgentSessionTeardownPhase = {
   name: string
@@ -66,6 +67,7 @@ export function structuredAgentSessionHostTeardownPhases(collaborators: {
   /** Opens this teardown's witnesses; each session's own is taken as eviction stops its child. */
   beginResumeMarkers: () => void
   recordResumeMarkers: () => Promise<void>
+  logger: StructuredAgentSessionLogger
 }): StructuredAgentSessionTeardownPhase[] {
   return [
     {
@@ -74,7 +76,9 @@ export function structuredAgentSessionHostTeardownPhases(collaborators: {
         try {
           collaborators.beginResumeMarkers()
         } catch {
-          console.warn('[structured-agent-session] capturing recovery witnesses failed')
+          collaborators.logger.warn('capturing recovery witnesses for teardown failed', {
+            scope: 'teardown-recovery-witnesses'
+          })
         }
       }
     },
@@ -90,7 +94,9 @@ export function structuredAgentSessionHostTeardownPhases(collaborators: {
       run: () =>
         withPhaseTimeout(collaborators.recordResumeMarkers, RESUME_MARKER_RECORD_TIMEOUT_MS).catch(
           () => {
-            console.warn('[structured-agent-session] recording recovery capsule failed')
+            collaborators.logger.warn('recording the recovery capsule at teardown failed', {
+              scope: 'teardown-recovery-capsule'
+            })
           }
         )
     },
@@ -168,7 +174,8 @@ export async function flushStructuredAgentSessionHost(
           retainSessionIds
         ),
       beginResumeMarkers: () => context.restartResume.beginTeardown(context.trigger),
-      recordResumeMarkers: context.restartResume.recordMarkers
+      recordResumeMarkers: context.restartResume.recordMarkers,
+      logger: context.deps.logger
     }),
     sessions: context.sessions,
     retainSessionIds,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-host-test-abandon.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-host-test-abandon.test.ts
index 2971ce4f79c..ee0bb2bee92 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-host-test-abandon.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-host-test-abandon.test.ts
@@ -19,6 +19,7 @@ import {
   hostTestMessage
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 
@@ -66,6 +67,7 @@ describe('abandoning a structured agent-session host', () => {
       setOption: async () => undefined
     }
     const host = new StructuredAgentSessionHost({
+      logger: createStructuredAgentSessionLogger(),
       store,
       adapter,
       probeOwner: async () => ({
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-host-test-harness.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-host-test-harness.ts
index f29d1b68e69..c7667531110 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-host-test-harness.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-host-test-harness.ts
@@ -29,6 +29,7 @@ import {
   hostTestOperationId,
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
+import { recordingProductionStructuredAgentSessionLogger } from './structured-agent-session-logger-test-support'
 
 const journals = createTrackedJournalOpener()
 
@@ -62,6 +63,7 @@ let root: string
 let recoveryCapsule: TrackedTestRecoveryCapsule
 let store: AgentSessionRecordStore
 let host: StructuredAgentSessionHost
+let log: ReturnType<typeof recordingProductionStructuredAgentSessionLogger>
 let acquire: Mock<StructuredAgentSessionAdapter['acquire']>
 let releaseAcquisition: Mock<NonNullable<StructuredAgentSessionAdapter['releaseAcquisition']>>
 let dispatch: Mock<StructuredAgentSessionAdapter['dispatch']>
@@ -152,7 +154,9 @@ beforeEach(async () => {
   setOption = vi.fn(async () => undefined)
   store = await openTestAgentSessionRecordStore(root)
   recoveryCapsule = new TrackedTestRecoveryCapsule(root)
+  log = recordingProductionStructuredAgentSessionLogger()
   host = new StructuredAgentSessionHost({
+    logger: log.logger,
     store,
     adapter: adapter(),
     journalDatabase: openTestJournalHostDatabase(root),
@@ -200,6 +204,8 @@ export function hostTestState() {
     root,
     store,
     host,
+    /** Every entry the beforeEach host logged; a host a test builds itself logs elsewhere. */
+    log,
     acquire,
     releaseAcquisition,
     dispatch,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-host-types.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-host-types.ts
index c2ec1833288..dcf708643e9 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-host-types.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-host-types.ts
@@ -17,6 +17,7 @@ import type {
 import type { AgentSessionAttachParams } from './structured-agent-session-attach'
 import type { StructuredAgentSessionStatusSink } from './structured-agent-session-status-feed'
 import type { AgentModelCatalogService } from '../agent-model-catalog/agent-model-catalog-service'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 export type StructuredAgentSessionCaller = { callerKey: string }
 
@@ -121,11 +122,9 @@ export type StructuredAgentSessionHostDeps = {
   idleSweep?: { intervalMs?: number; idleMs?: number }
   /** Whether an orchestration dispatch still owns this session's worker; absent answers no. */
   hasOpenDispatch?: (record: AgentSessionRecord) => boolean
-  onEventSinkError?: (input: { sessionId: string; error: unknown }) => void
-  /** Lease bookkeeping run for startup or a read (the reconcile, or resolving a chat's recovery)
-   *  that refused or threw, once per distinct failure. Startup and the read carry on: the next
-   *  attach or send reconciles and resolves recovery again before it acts. */
-  onLeaseReconcileFailure?: (failure: unknown) => void
+  /** Where every failure the host carries on past is reported. Required: a host without one would
+   *  drop exactly the failures nobody sees in the UI. */
+  logger: StructuredAgentSessionLogger
   /** Every status projection this host publishes. `replay` marks a re-projection of state the host
    *  already knew (restore, an arriving subscriber) rather than a fresh journal edge. */
   onSessionStatusChanged?: (
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-host.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-host.test.ts
index 4b1993ea302..d666e4a5c94 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-host.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-host.test.ts
@@ -28,6 +28,7 @@ import {
   hostTestMessage
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 let root: string
 let store: AgentSessionRecordStore
@@ -132,6 +133,7 @@ describe('attach', () => {
         }
       }))
     host = new StructuredAgentSessionHost({
+      logger: createStructuredAgentSessionLogger(),
       store,
       adapter: { ...adapter(), acquire },
       journalDatabase: openTestJournalHostDatabase(root),
@@ -562,6 +564,7 @@ describe('restart', () => {
   ) {
     store = await openTestAgentSessionRecordStore(root)
     host = new StructuredAgentSessionHost({
+      logger: createStructuredAgentSessionLogger(),
       store,
       adapter: { ...adapter(), ...adapterOverrides },
       journalDatabase: openTestJournalHostDatabase(root),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-host.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-host.ts
index 37f4a196610..95cc822bba1 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-host.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-host.ts
@@ -56,6 +56,7 @@ import { structuredAgentSessionRestartResumeSurfaces } from './structured-agent-
 import { createStructuredAgentSessionConversationDelivery } from './structured-agent-session-host-delivery'
 import { structuredAgentSessionConversationFence } from './structured-agent-session-provider-child'
 import { wireStructuredAgentSessionQueuedMessages } from './structured-agent-session-queued-wiring'
+import * as sessionLogger from './structured-agent-session-logger'
 export type { StructuredAgentSessionHostDeps } from './structured-agent-session-host-types'
 
 export class StructuredAgentSessionHost {
@@ -68,7 +69,7 @@ export class StructuredAgentSessionHost {
       this.subscribers.publish(sessionId, journal)
       this.conversationDelivery.afterCommit(sessionId, journal)
     },
-    onDeliveryError: (sessionId, error) => this.deps.onEventSinkError?.({ sessionId, error }),
+    logger: sessionLogger.deferredStructuredAgentSessionLogger(() => this.deps.logger),
     onOpened: (sessionId) => this.queued.drain.schedule(sessionId),
     now: () => this.now()
   })
@@ -101,6 +102,8 @@ export class StructuredAgentSessionHost {
   readonly restartResume: StructuredAgentSessionRestartResume
 
   constructor(readonly deps: StructuredAgentSessionHostDeps) {
+    // Every collaborator reads this copy, so a logger that throws cannot fail what it reports.
+    this.deps = deps = sessionLogger.withNeverThrowingLogger(deps)
     this.clientDelivery.watchAtRestCommands(deps.adapter)
     this.backgroundTasks = new StructuredAgentSessionBackgroundTaskChannel(
       deps,
@@ -158,8 +161,7 @@ export class StructuredAgentSessionHost {
         ),
       publishStatus: this.clientDelivery.publishStatusAndSettlement,
       serialize: (sessionId, task) => this.tasks.trackAttach(this.serialize(sessionId, task)),
-      now: () => this.now(),
-      onBarrierError: (sessionId, error) => deps.onEventSinkError?.({ sessionId, error })
+      now: () => this.now()
     })
     this.restartResume = createStructuredAgentSessionRestartResume(deps, this.sessions, {
       ...structuredAgentSessionRestartResumeSurfaces(this, this.now),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-idle-sweep.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-idle-sweep.test.ts
index cad1d17d94f..8ff4cdbeb42 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-idle-sweep.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-idle-sweep.test.ts
@@ -320,8 +320,14 @@ describe('the idle sweep with no child running (P2-22 ii)', () => {
       stopAgent,
       stopStartingAgent: stopAgent,
       closeConversation,
-      onError: (_id, error) => {
-        throw error
+      // A failed step fails the test.
+      logger: {
+        warn: (_message, fields) => {
+          throw fields.error
+        },
+        error: (_message, fields) => {
+          throw fields.error
+        }
       }
     })
     await sweep.tick()
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-idle-sweep.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-idle-sweep.ts
index 14cc0e56030..e9b0e1b45c6 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-idle-sweep.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-idle-sweep.ts
@@ -14,6 +14,7 @@ import { isQueuedAgentJournalSubmission } from '../../../shared/agent-session-qu
 import type { AgentJournalRenderItem } from '../../../shared/agent-session-journal-types'
 import type { AgentChildWorkView } from '../../../shared/agent-status-child-work-view'
 import type { StructuredAgentSessionHostSession } from './structured-agent-session-host-types'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 export const STRUCTURED_AGENT_SESSION_IDLE_SWEEP_INTERVAL_MS = 5 * 60_000
 export const STRUCTURED_AGENT_SESSION_IDLE_MS = 30 * 60_000
@@ -37,7 +38,7 @@ export type StructuredAgentSessionIdleSweepDeps = {
   stopAgent: (sessionId: string) => Promise<void>
   stopStartingAgent: (sessionId: string) => Promise<void>
   closeConversation: (sessionId: string) => Promise<boolean>
-  onError: (sessionId: string, error: unknown) => void
+  logger: StructuredAgentSessionLogger
   intervalMs?: number
   idleMs?: number
 }
@@ -87,7 +88,13 @@ export class StructuredAgentSessionIdleSweep {
         [...this.deps.sessions.keys()].map((sessionId) =>
           this.deps
             .serialize(sessionId, () => this.tickUnderSerialize(sessionId))
-            .catch((error: unknown) => this.deps.onError(sessionId, error))
+            .catch((error: unknown) =>
+              this.deps.logger.warn('an idle sweep step failed', {
+                scope: 'idle-sweep',
+                sessionId,
+                error
+              })
+            )
         )
       )
     } finally {
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-import-mismatch.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-import-mismatch.test.ts
index a173a3ad661..5a384ce2bb9 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-import-mismatch.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-import-mismatch.test.ts
@@ -25,6 +25,7 @@ import {
   HOST_TEST_SESSION as SESSION,
   hostTestMessage
 } from './structured-agent-session-host-test-data'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const { copy } = vi.hoisted(() => ({ copy: { mismatched: false } }))
 
@@ -93,6 +94,7 @@ async function relaunchWithMismatchedCopy(): Promise<StructuredAgentSessionHost>
   })
   const store = await openTestAgentSessionRecordStore(relaunched)
   const host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: adapter(),
     journalDatabase: openTestJournalHostDatabase(relaunched),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-journal-corruption.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-journal-corruption.test.ts
index ac4bb5e2f4d..bd7d735abbc 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-journal-corruption.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-journal-corruption.test.ts
@@ -16,6 +16,9 @@ import {
 } from './structured-agent-session-host-test-harness'
 import { hostTestMessage } from './structured-agent-session-host-test-data'
 
+const STOP_LEDGER_ROW_FAILED =
+  "[agent-session] stop-ledger-row: writing Stop's ledger row failed; Stop runs without it"
+
 let root: string
 let store: AgentSessionRecordStore
 let host: StructuredAgentSessionHost
@@ -70,9 +73,10 @@ it('refuses a send as corrupt when SQLite reports damage, and still stops the ag
   // the caller sees, after the fact.
   await expect(stop()).rejects.toBe(damaged)
   expect(cancelTurn).toHaveBeenCalledTimes(1)
-  expect(warn).toHaveBeenCalledWith("[agent-session] Stop's ledger row skipped:", {
+  expect(warn).toHaveBeenCalledWith(STOP_LEDGER_ROW_FAILED, {
+    scope: 'stop-ledger-row',
     sessionId: expect.any(String),
-    error: 'database disk image is malformed'
+    error: expect.objectContaining({ message: 'database disk image is malformed' })
   })
   // The restart-offer withdrawal the attach started holds its lock until it ends.
   await hostTestRecoveryCapsuleSettled()
@@ -93,9 +97,10 @@ it.each([
     value: { turnId: 'turn-1', cancelled: true }
   })
   expect(cancelTurn).toHaveBeenCalledTimes(1)
-  expect(warn).toHaveBeenCalledWith("[agent-session] Stop's ledger row skipped:", {
+  expect(warn).toHaveBeenCalledWith(STOP_LEDGER_ROW_FAILED, {
+    scope: 'stop-ledger-row',
     sessionId: expect.any(String),
-    error: error.message
+    error
   })
 })
 
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-late-settlement.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-late-settlement.test.ts
index 44615a27ee8..f91fc57c055 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-late-settlement.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-late-settlement.test.ts
@@ -29,6 +29,7 @@ import {
 import { agentSessionFailureFact } from '../../../shared/agent-session-failure'
 import { agentSessionFailureWords } from '../../../shared/agent-session-failure-words'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 
@@ -95,6 +96,7 @@ beforeEach(async () => {
   closeSession = vi.fn(async () => true)
   store = await openTestAgentSessionRecordStore(root)
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: {
       acquire: vi.fn(async ({ fence }) => ({
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-lease-renewer.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-lease-renewer.test.ts
index 9399e4d0242..c3eb1e324e9 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-lease-renewer.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-lease-renewer.test.ts
@@ -9,6 +9,7 @@ import {
 import type { AgentSessionRecordStore } from '../../runtime/agent-session-record-store'
 import { openTestAgentSessionRecordStore } from '../../runtime/agent-session-record-store-test-harness'
 import { StructuredAgentSessionLeaseRenewer } from './structured-agent-session-lease-renewer'
+import { recordingStructuredAgentSessionLogger } from './structured-agent-session-logger-test-support'
 
 const NOW = 1_800_000_000_000
 const roots: string[] = []
@@ -103,6 +104,7 @@ describe('structured agent-session lease renewal', () => {
         )
     )
     const renewer = new StructuredAgentSessionLeaseRenewer({
+      logger: recordingStructuredAgentSessionLogger().logger,
       store: { listRecords: () => records, renewLeases } as unknown as AgentSessionRecordStore,
       probe: vi.fn(),
       probeMany,
@@ -144,7 +146,7 @@ describe('structured agent-session lease renewal', () => {
       }
       return records[0]!
     })
-    const onError = vi.fn()
+    const log = recordingStructuredAgentSessionLogger()
     const renewer = new StructuredAgentSessionLeaseRenewer({
       store: {
         listRecords: () => records,
@@ -156,14 +158,15 @@ describe('structured agent-session lease renewal', () => {
         matchedOn: ['spawn-token' as const]
       }),
       now: () => NOW + 10_000,
-      onError
+      logger: log.logger
     })
 
     await renewer.renewNow()
 
     expect(renewLeases).toHaveBeenCalledOnce()
     expect(renewLease).toHaveBeenCalledTimes(2)
-    expect(onError).toHaveBeenCalledWith({
+    expect(log.entries.map((entry) => entry.fields)).toContainEqual({
+      scope: 'lease-renewal',
       sessionId: 'session-b',
       error: expect.objectContaining({ message: 'agent_session_checkpoint_stale' })
     })
@@ -174,6 +177,7 @@ describe('structured agent-session lease renewal', () => {
     const store = await liveStore()
     let now = NOW
     const renewer = new StructuredAgentSessionLeaseRenewer({
+      logger: recordingStructuredAgentSessionLogger().logger,
       store,
       probe: async () => ({
         outcome: 'identity-matched',
@@ -203,6 +207,7 @@ describe('structured agent-session lease renewal', () => {
       releaseProbe = resolve
     })
     const renewer = new StructuredAgentSessionLeaseRenewer({
+      logger: recordingStructuredAgentSessionLogger().logger,
       store,
       probe: async () => {
         await probing
@@ -228,6 +233,7 @@ describe('structured agent-session lease renewal', () => {
       matchedOn: ['process-start-time' as const]
     }))
     const renewer = new StructuredAgentSessionLeaseRenewer({
+      logger: recordingStructuredAgentSessionLogger().logger,
       store,
       probe,
       now: () => NOW + 10_000
@@ -241,18 +247,19 @@ describe('structured agent-session lease renewal', () => {
 
   it('stops extending the lease when child proof is no longer sufficient', async () => {
     const store = await liveStore()
-    const onError = vi.fn()
+    const log = recordingStructuredAgentSessionLogger()
     const renewer = new StructuredAgentSessionLeaseRenewer({
       store,
       probe: async () => ({ outcome: 'indeterminate', reason: 'probe unavailable' }),
       now: () => NOW + 10_000,
-      onError
+      logger: log.logger
     })
 
     await renewer.renewNow()
 
     expect(store.getRecord('session-renewal')?.lease.lastRenewedAt).toBe(NOW)
-    expect(onError).toHaveBeenCalledWith({
+    expect(log.entries.map((entry) => entry.fields)).toContainEqual({
+      scope: 'lease-renewal',
       sessionId: 'session-renewal',
       error: expect.any(Error)
     })
@@ -271,6 +278,7 @@ describe('structured agent-session lease renewal', () => {
       matchedOn: ['process-start-time' as const]
     }))
     const renewer = new StructuredAgentSessionLeaseRenewer({
+      logger: recordingStructuredAgentSessionLogger().logger,
       store,
       probe,
       now: () => NOW + 10_000
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-lease-renewer.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-lease-renewer.ts
index 21d79020270..7888d4867e2 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-lease-renewer.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-lease-renewer.ts
@@ -4,13 +4,14 @@ import {
   AGENT_SESSION_LEASE_TTL_MS,
   type AgentSessionRecordStore
 } from '../../runtime/agent-session-record-store'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const RENEW_INTERVAL_MS = Math.floor(AGENT_SESSION_LEASE_TTL_MS / 3)
 
 export class StructuredAgentSessionLeaseRenewer {
   private timer: ReturnType<typeof setInterval> | null = null
   private running = false
-  /** The tick in flight. Never rejects: the timer path reports renewal failures through `onError`,
+  /** The tick in flight. Never rejects: the timer path logs renewal failures,
    *  and stopping must not turn one into a teardown failure as well. */
   private inFlight: Promise<void> = Promise.resolve()
 
@@ -22,7 +23,7 @@ export class StructuredAgentSessionLeaseRenewer {
         records: readonly AgentSessionRecord[]
       ) => Promise<Map<string, AgentSessionOwnerProbe>>
       now: () => number
-      onError?: (input: { sessionId: string; error: unknown }) => void
+      logger: StructuredAgentSessionLogger
       intervalMs?: number
     }
   ) {}
@@ -106,7 +107,7 @@ export class StructuredAgentSessionLeaseRenewer {
       if (result.status === 'rejected') {
         const renewal = renewals[index]
         if (renewal) {
-          this.input.onError?.({ sessionId: renewal.sessionId, error: result.reason })
+          this.reportFailure(renewal.sessionId, result.reason)
         }
       }
     })
@@ -126,15 +127,24 @@ export class StructuredAgentSessionLeaseRenewer {
         if (result.status === 'fulfilled') {
           probes.set(record.sessionId, result.value)
         } else {
-          this.input.onError?.({ sessionId: record.sessionId, error: result.reason })
+          this.reportFailure(record.sessionId, result.reason)
         }
       }
       return probes
     } catch (error) {
       for (const record of records) {
-        this.input.onError?.({ sessionId: record.sessionId, error })
+        this.reportFailure(record.sessionId, error)
       }
       return new Map()
     }
   }
+
+  /** Lease and ownership failures are transient: the next tick, attach or send retries them. */
+  private reportFailure(sessionId: string, error: unknown): void {
+    this.input.logger.warn('renewing a chat lease failed', {
+      scope: 'lease-renewal',
+      sessionId,
+      error
+    })
+  }
 }
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-legacy-handoff-record.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-legacy-handoff-record.test.ts
index 706d0d8fc3f..c25640cc81c 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-legacy-handoff-record.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-legacy-handoff-record.test.ts
@@ -24,6 +24,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 
@@ -42,6 +43,7 @@ let dispatch: Mock<StructuredAgentSessionAdapter['dispatch']>
 
 function openHost(): void {
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: {
       acquire,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-log-repeats.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-log-repeats.ts
new file mode 100644
index 00000000000..d805a2191d2
--- /dev/null
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-log-repeats.ts
@@ -0,0 +1,54 @@
+// Keeps one failure that recurs on a timer (lease renewal, idle sweep) or on every publication
+// (status feed) from flooding the shared, rotated trace file and erasing the history around it.
+
+/** How long a repeated entry stays quiet after it is written. */
+export const STRUCTURED_AGENT_SESSION_LOG_REPEAT_WINDOW_MS = 5 * 60_000
+const MAX_TRACKED_REPEATS = 256
+
+type TrackedRepeat = { writtenAt: number; suppressed: number }
+
+export type StructuredAgentSessionLogRepeats = {
+  /** `null` swallows this entry; a number writes it, carrying the repeats swallowed since the last. */
+  admit: (key: string) => number | null
+}
+
+export function createStructuredAgentSessionLogRepeats(options?: {
+  now?: () => number
+  windowMs?: number
+  maxTracked?: number
+}): StructuredAgentSessionLogRepeats {
+  const now = options?.now ?? Date.now
+  const windowMs = options?.windowMs ?? STRUCTURED_AGENT_SESSION_LOG_REPEAT_WINDOW_MS
+  const maxTracked = options?.maxTracked ?? MAX_TRACKED_REPEATS
+  // Insertion order is write order, so the first key is the one written longest ago.
+  const tracked = new Map<string, TrackedRepeat>()
+
+  const makeRoom = (at: number): void => {
+    for (const [key, repeat] of tracked) {
+      if (at - repeat.writtenAt >= windowMs) {
+        tracked.delete(key)
+      }
+    }
+    const oldest = tracked.keys().next()
+    if (tracked.size >= maxTracked && !oldest.done) {
+      tracked.delete(oldest.value)
+    }
+  }
+
+  return {
+    admit: (key) => {
+      const at = now()
+      const repeat = tracked.get(key)
+      if (repeat && at - repeat.writtenAt < windowMs) {
+        repeat.suppressed += 1
+        return null
+      }
+      tracked.delete(key)
+      if (tracked.size >= maxTracked) {
+        makeRoom(at)
+      }
+      tracked.set(key, { writtenAt: at, suppressed: 0 })
+      return repeat?.suppressed ?? 0
+    }
+  }
+}
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-logger-test-support.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-logger-test-support.ts
new file mode 100644
index 00000000000..f4413c4d11b
--- /dev/null
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-logger-test-support.ts
@@ -0,0 +1,58 @@
+import {
+  createStructuredAgentSessionLogger,
+  type StructuredAgentSessionLogFields,
+  type StructuredAgentSessionLogger
+} from './structured-agent-session-logger'
+
+export type RecordedStructuredAgentSessionLog = {
+  level: keyof StructuredAgentSessionLogger
+  message: string
+  fields: StructuredAgentSessionLogFields
+}
+
+/** A logger that keeps every entry, for tests that assert a failure was reported. */
+export function recordingStructuredAgentSessionLogger(): {
+  logger: StructuredAgentSessionLogger
+  entries: RecordedStructuredAgentSessionLog[]
+  scopes: () => string[]
+} {
+  const entries: RecordedStructuredAgentSessionLog[] = []
+  return {
+    logger: {
+      warn: (message, fields) => entries.push({ level: 'warn', message, fields }),
+      error: (message, fields) => entries.push({ level: 'error', message, fields })
+    },
+    entries,
+    scopes: () => entries.map((entry) => entry.fields.scope)
+  }
+}
+
+/** A recording logger that also prints as production does, for a harness whose tests read either:
+ *  the entries hold every level and every field, whatever the console mirror keeps. */
+export function recordingProductionStructuredAgentSessionLogger(): ReturnType<
+  typeof recordingStructuredAgentSessionLogger
+> {
+  const recording = recordingStructuredAgentSessionLogger()
+  const production = createStructuredAgentSessionLogger()
+  return {
+    ...recording,
+    logger: {
+      warn: (message, fields) => {
+        recording.logger.warn(message, fields)
+        production.warn(message, fields)
+      },
+      error: (message, fields) => {
+        recording.logger.error(message, fields)
+        production.error(message, fields)
+      }
+    }
+  }
+}
+
+/** What an event sink built outside a host needs: the session it writes for, and a logger. */
+export function testEventSinkLogging(sessionId = 'session-1'): {
+  sessionId: string
+  logger: StructuredAgentSessionLogger
+} {
+  return { sessionId, logger: recordingStructuredAgentSessionLogger().logger }
+}
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-logger.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-logger.test.ts
new file mode 100644
index 00000000000..0cacbda8587
--- /dev/null
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-logger.test.ts
@@ -0,0 +1,212 @@
+import { afterEach, beforeEach, describe, expect, it, vi, type Mock } from 'vitest'
+import { _resetTracerForTests, setActiveSink } from '../../observability/tracer'
+import {
+  AgentSessionRefusalError,
+  agentSessionRefusalError,
+  refuse
+} from '../../../shared/agent-session-wire-refusals'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
+import {
+  STRUCTURED_AGENT_SESSION_LOG_REPEAT_WINDOW_MS as WINDOW_MS,
+  createStructuredAgentSessionLogRepeats
+} from './structured-agent-session-log-repeats'
+
+let push: Mock<(record: unknown) => void>
+let clock: number
+
+function written(): { name: string; attributes: Record<string, unknown>; exit: unknown }[] {
+  // As the sink writes them: one JSON line per span.
+  return JSON.parse(JSON.stringify(push.mock.calls.map(([span]) => span)))
+}
+
+beforeEach(() => {
+  push = vi.fn<(record: unknown) => void>()
+  clock = 1_000_000
+  setActiveSink({ push, flush: () => {}, close: () => {} })
+  vi.spyOn(console, 'warn').mockImplementation(() => undefined)
+  vi.spyOn(console, 'error').mockImplementation(() => undefined)
+})
+
+afterEach(() => {
+  _resetTracerForTests()
+  vi.restoreAllMocks()
+})
+
+describe('a failure that repeats', () => {
+  it('is written once per window, then once more carrying how many repeats it swallowed', () => {
+    const logger = createStructuredAgentSessionLogger({ now: () => clock })
+    const renew = (): void =>
+      logger.warn('renewing a chat lease failed', {
+        scope: 'lease-renewal',
+        sessionId: 'session-1',
+        error: new Error('database is locked')
+      })
+
+    for (let tick = 0; tick < 30; tick += 1) {
+      renew()
+      clock += 10_000
+    }
+    expect(written()).toHaveLength(1)
+    expect(written()[0]?.attributes).not.toHaveProperty('suppressed')
+    expect(console.warn).toHaveBeenCalledOnce()
+
+    clock += WINDOW_MS
+    renew()
+    expect(written()).toHaveLength(2)
+    expect(written()[1]?.attributes).toMatchObject({ suppressed: 29, sessionId: 'session-1' })
+    expect(console.warn).toHaveBeenLastCalledWith(
+      '[agent-session] lease-renewal: renewing a chat lease failed',
+      expect.objectContaining({ suppressed: 29 })
+    )
+
+    renew()
+    expect(written()).toHaveLength(2)
+  })
+
+  it('never merges different sessions, scopes, levels, messages or errors', () => {
+    const logger = createStructuredAgentSessionLogger({ now: () => clock })
+    for (let round = 0; round < 3; round += 1) {
+      logger.warn('renewing a chat lease failed', { scope: 'lease-renewal', sessionId: 'a' })
+      logger.warn('renewing a chat lease failed', { scope: 'lease-renewal', sessionId: 'b' })
+      logger.warn('renewing a chat lease failed', { scope: 'idle-sweep', sessionId: 'a' })
+      logger.error('renewing a chat lease failed', { scope: 'lease-renewal', sessionId: 'a' })
+      logger.warn('a different step failed', { scope: 'lease-renewal', sessionId: 'a' })
+      logger.warn('a different step failed', {
+        scope: 'lease-renewal',
+        sessionId: 'a',
+        error: new Error('disk full')
+      })
+    }
+
+    expect(written().map((span) => [span.name, span.attributes['sessionId']])).toEqual([
+      ['agentSession.lease-renewal', 'a'],
+      ['agentSession.lease-renewal', 'b'],
+      ['agentSession.idle-sweep', 'a'],
+      ['agentSession.lease-renewal', 'a'],
+      ['agentSession.lease-renewal', 'a'],
+      ['agentSession.lease-renewal', 'a']
+    ])
+  })
+
+  it('writes a failure whose cause, refusal reason or value differs, and swallows a true repeat', () => {
+    const logger = createStructuredAgentSessionLogger({ now: () => clock })
+    // A refusal's message is its bare code: only the cause tells these two apart.
+    const unreadable = (cause: Error): Error =>
+      new AgentSessionRefusalError(
+        refuse(
+          'agent_session_journal_unreadable',
+          { reason: 'journalUnavailable' },
+          'agent_session_journal_unreadable'
+        ),
+        { cause }
+      )
+    const report = (error: unknown): void =>
+      logger.warn('recording an opened chat tab failed', {
+        scope: 'tab-visibility-open',
+        sessionId: 'session-1',
+        error
+      })
+    const denied = Object.assign(new Error('EACCES: permission denied'), { code: 'EACCES' })
+    const failing = Object.assign(new Error('EIO: i/o error'), { code: 'EIO' })
+
+    report(unreadable(denied))
+    report(unreadable(denied))
+    report(unreadable(failing))
+    report(
+      agentSessionRefusalError('agent_session_journal_unreadable', { reason: 'journalCorrupt' })
+    )
+    report({ code: 'busy', attempt: 1 })
+    report({ attempt: 1, code: 'busy' })
+    report({ code: 'locked', attempt: 1 })
+
+    expect(
+      written().map((span) => span.attributes['errorCause'] ?? span.attributes['error'])
+    ).toEqual([
+      ['Error: EACCES: permission denied'],
+      ['Error: EIO: i/o error'],
+      undefined,
+      { code: 'busy', attempt: 1 },
+      { code: 'locked', attempt: 1 }
+    ])
+    expect(written()[2]?.attributes).toMatchObject({ refusalReason: 'journalCorrupt' })
+    expect(written()[0]?.attributes).toMatchObject({ refusalReason: 'journalUnavailable' })
+  })
+
+  it('writes one message under another error name, or as a refusal, as separate failures', () => {
+    const logger = createStructuredAgentSessionLogger({ now: () => clock })
+    const renew = (error: Error): void =>
+      logger.warn('renewing a chat lease failed', { scope: 'lease-renewal', sessionId: 'a', error })
+    const unreadableRecord = (): Error => new Error('execution_owner_reconciling')
+    const reconciling = (): Error =>
+      agentSessionRefusalError('execution_owner_reconciling', { reason: 'hostReconciling' })
+
+    for (let tick = 0; tick < 3; tick += 1) {
+      renew(unreadableRecord())
+      renew(reconciling())
+      renew(new TypeError('execution_owner_reconciling'))
+    }
+
+    expect(written().map((span) => span.exit)).toEqual([
+      expect.objectContaining({ cause: expect.stringMatching(/^Error: /) }),
+      expect.objectContaining({ cause: expect.stringMatching(/^AgentSessionRefusalError: /) }),
+      expect.objectContaining({ cause: expect.stringMatching(/^TypeError: /) })
+    ])
+  })
+
+  it('tracks a bounded number of repeating entries', () => {
+    const repeats = createStructuredAgentSessionLogRepeats({ now: () => clock, maxTracked: 2 })
+    expect(repeats.admit('a')).toBe(0)
+    expect(repeats.admit('b')).toBe(0)
+    expect(repeats.admit('a')).toBeNull()
+    // A third key evicts the one written longest ago, so `a` is written again.
+    expect(repeats.admit('c')).toBe(0)
+    expect(repeats.admit('a')).toBe(0)
+    expect(repeats.admit('c')).toBeNull()
+  })
+})
+
+describe('what an Error leaves in the trace file', () => {
+  it('carries its code and its causes, depth-capped, by name and message only', () => {
+    const denied = Object.assign(new Error('EACCES: permission denied, open'), {
+      code: 'EACCES',
+      path: '/private/payload'
+    })
+    const locked = Object.assign(new Error('database is locked'), {
+      code: 'ERR_SQLITE_ERROR',
+      errcode: 5
+    })
+    const chain = new Error('agent_session_store_corrupt', {
+      cause: new Error('read failed', {
+        cause: new Error('third', { cause: new Error('fourth', { cause: new Error('fifth') }) })
+      })
+    })
+
+    const logger = createStructuredAgentSessionLogger({ now: () => clock })
+    logger.warn('importing legacy records failed', { scope: 'legacy-record-import', error: chain })
+    logger.warn('opening the journal failed', {
+      scope: 'journal-database-open',
+      error: new Error('opening failed', { cause: denied })
+    })
+    logger.error('writing events failed', { scope: 'journal-event-sink', error: locked })
+
+    const [corrupt, open, sqlite] = written()
+    expect(corrupt?.attributes['errorCause']).toEqual([
+      'Error: read failed',
+      'Error: third',
+      'Error: fourth'
+    ])
+    expect(open?.attributes['errorCause']).toEqual(['Error: EACCES: permission denied, open'])
+    expect(JSON.stringify(written())).not.toContain('/private/payload')
+    expect(sqlite?.attributes).toMatchObject({ errorCode: 'ERR_SQLITE_ERROR', errorErrcode: 5 })
+    expect(sqlite?.exit).toMatchObject({ cause: expect.stringContaining('database is locked') })
+  })
+
+  it('names the code of a cause whose message does not', () => {
+    const logger = createStructuredAgentSessionLogger({ now: () => clock })
+    logger.warn('x failed', {
+      scope: 'x',
+      error: new Error('x', { cause: Object.assign(new Error('no space'), { code: 'ENOSPC' }) })
+    })
+    expect(written()[0]?.attributes['errorCause']).toEqual(['Error: no space [ENOSPC]'])
+  })
+})
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-logger.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-logger.ts
new file mode 100644
index 00000000000..1244e974532
--- /dev/null
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-logger.ts
@@ -0,0 +1,173 @@
+// Where the structured chat host and its runtime report a failure they carry on past.
+//
+// One required dependency rather than a callback per failure: a host built without it does not
+// compile, so no failure path can quietly drop what went wrong. The default writes each entry to
+// the host's local trace file (the desktop's `<userData>/logs/main.trace.ndjson`, collected by the
+// diagnostic bundle; orcad's `<data-root>/logs/orcad.trace.ndjson`) and to the console.
+
+import { isAgentSessionRefusalError } from '../../../shared/agent-session-wire-refusals'
+import { startSpan } from '../../observability/tracer'
+import { createStructuredAgentSessionLogRepeats } from './structured-agent-session-log-repeats'
+
+export type StructuredAgentSessionLogFields = {
+  /** The step that failed; a stable name a log search can find. */
+  readonly scope: string
+  readonly sessionId?: string
+  readonly error?: unknown
+  readonly [field: string]: unknown
+}
+
+export type StructuredAgentSessionLogger = {
+  warn: (message: string, fields: StructuredAgentSessionLogFields) => void
+  error: (message: string, fields: StructuredAgentSessionLogFields) => void
+}
+
+type LogLevel = keyof StructuredAgentSessionLogger
+
+const guarded = new WeakSet<StructuredAgentSessionLogger>()
+
+/** Reporting is bookkeeping: a logger that throws must never fail the operation it reports. */
+export function neverThrowingStructuredAgentSessionLogger(
+  logger: StructuredAgentSessionLogger
+): StructuredAgentSessionLogger {
+  if (guarded.has(logger)) {
+    return logger
+  }
+  const call =
+    (level: LogLevel) =>
+    (message: string, fields: StructuredAgentSessionLogFields): void => {
+      try {
+        logger[level](message, fields)
+      } catch (loggerError) {
+        try {
+          console.warn(`[agent-session] ${message}`, { ...fields, loggerError })
+        } catch {
+          // Nothing is left to report to.
+        }
+      }
+    }
+  const safe: StructuredAgentSessionLogger = { warn: call('warn'), error: call('error') }
+  guarded.add(safe)
+  return safe
+}
+
+/** A copy of `deps` whose logger cannot throw; every collaborator built from it inherits that. */
+export function withNeverThrowingLogger<T extends { logger: StructuredAgentSessionLogger }>(
+  deps: T
+): T {
+  return { ...deps, logger: neverThrowingStructuredAgentSessionLogger(deps.logger) }
+}
+
+/** The logger `resolve` returns at each call, for a collaborator built before the host's deps. */
+export function deferredStructuredAgentSessionLogger(
+  resolve: () => StructuredAgentSessionLogger
+): StructuredAgentSessionLogger {
+  return {
+    warn: (message, fields) => resolve().warn(message, fields),
+    error: (message, fields) => resolve().error(message, fields)
+  }
+}
+
+/** The production logger: a failed span in the local trace file, plus the console. A repeat of
+ *  the same entry is written at most once per window, carrying how many were swallowed. */
+export function createStructuredAgentSessionLogger(options?: {
+  now?: () => number
+}): StructuredAgentSessionLogger {
+  const repeats = createStructuredAgentSessionLogRepeats({ now: options?.now })
+  const write =
+    (level: LogLevel) =>
+    (message: string, fields: StructuredAgentSessionLogFields): void => {
+      const { scope, error, ...rest } = fields
+      const attributes = { level, message, ...rest, ...errorAttributes(error) }
+      // Keyed on all the entry writes but its stack: only a failure writing the same entry repeats.
+      const suppressed = repeats.admit(
+        stableJson([
+          scope,
+          attributes,
+          error instanceof Error ? `${error.name}: ${error.message}` : null
+        ])
+      )
+      if (suppressed === null) {
+        return
+      }
+      const span = startSpan(`agentSession.${scope}`, {
+        attributes: suppressed > 0 ? { ...attributes, suppressed } : attributes
+      })
+      span.fail(error instanceof Error ? error : message)
+      const print = level === 'error' ? console.error : console.warn
+      print(
+        `[agent-session] ${scope}: ${message}`,
+        suppressed > 0 ? { ...fields, suppressed } : fields
+      )
+    }
+  return neverThrowingStructuredAgentSessionLogger({ warn: write('warn'), error: write('error') })
+}
+
+const MAX_LOGGED_CAUSES = 3
+
+/** The span's failure carries an Error's name, message and stack; its code and causes ride here.
+ *  A value that is not an Error is written whole, as it would serialize. */
+function errorAttributes(error: unknown): Record<string, unknown> {
+  if (error === undefined) {
+    return {}
+  }
+  if (!(error instanceof Error)) {
+    return { error }
+  }
+  const causes: string[] = []
+  let cause: unknown = error.cause
+  // Name and message only: a cause's own fields can carry what the failing step was handling.
+  while (cause !== undefined && causes.length < MAX_LOGGED_CAUSES) {
+    if (cause instanceof Error) {
+      causes.push(`${cause.name}: ${cause.message}${codeSuffix(cause)}`)
+      cause = cause.cause
+    } else {
+      causes.push(typeof cause === 'object' && cause !== null ? '[non-error cause]' : String(cause))
+      cause = undefined
+    }
+  }
+  const code = errorCode(error)
+  // node:sqlite's `code` is one generic value; `errcode` tells SQLITE_BUSY from SQLITE_FULL.
+  const sqliteCode = codeValue('errcode' in error ? error.errcode : undefined)
+  // A refusal's message is its bare code; its reason is wire-safe and tells refusals apart.
+  const details = isAgentSessionRefusalError(error) ? error.refusal.details : undefined
+  const reason = details && 'reason' in details ? details.reason : undefined
+  return {
+    ...(code !== undefined ? { errorCode: code } : {}),
+    ...(sqliteCode !== undefined ? { errorErrcode: sqliteCode } : {}),
+    ...(typeof reason === 'string' ? { refusalReason: reason } : {}),
+    ...(causes.length > 0 ? { errorCause: causes } : {})
+  }
+}
+
+/** The same value always renders the same: object keys sorted, and no throw on a cycle. */
+function stableJson(value: unknown): string {
+  try {
+    return JSON.stringify(value, (_key, inner: unknown) => {
+      if (typeof inner === 'bigint') {
+        return String(inner)
+      }
+      if (typeof inner !== 'object' || inner === null || Array.isArray(inner)) {
+        return inner
+      }
+      return Object.fromEntries(
+        Object.entries(inner).sort(([left], [right]) => (left < right ? -1 : 1))
+      )
+    })
+  } catch {
+    return String(value)
+  }
+}
+
+function errorCode(error: Error): string | number | undefined {
+  return codeValue('code' in error ? error.code : undefined)
+}
+
+function codeValue(value: unknown): string | number | undefined {
+  return typeof value === 'string' || typeof value === 'number' ? value : undefined
+}
+
+function codeSuffix(error: Error): string {
+  const code = errorCode(error)
+  return code !== undefined && !error.message.includes(String(code)) ? ` [${code}]` : ''
+}
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-main-agent-working-agreement.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-main-agent-working-agreement.test.ts
index aa4a9547001..9ab31743cf4 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-main-agent-working-agreement.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-main-agent-working-agreement.test.ts
@@ -37,6 +37,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 const PROVIDER_ROW = { provider: 'codex' as const, threadId: THREAD, turnId: 'turn-1' }
@@ -62,6 +63,7 @@ beforeEach(async () => {
   dispatch = vi.fn(async () => ({ state: 'admitted' as const }))
   store = await openTestAgentSessionRecordStore(root)
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: {
       acquire: async (input) => {
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-mutation-admission.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-mutation-admission.ts
index 3e96a02ce26..6199531c8ee 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-mutation-admission.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-mutation-admission.ts
@@ -38,6 +38,7 @@ import type { MutationPlan } from './structured-agent-session-mutation-plans'
 import { runSettledAgentSessionMutation } from './structured-agent-session-operation-settlement'
 import { resolveAgentSessionReplayOutcome } from './structured-agent-session-replay-outcome'
 import type { AgentSessionTurnContext } from './structured-agent-session-turns'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 // The code is shared with the client so a read that refuses this way can be told apart from a
 // transcript that failed to load; the two must never drift apart.
@@ -61,6 +62,7 @@ export type AgentSessionMutationSessionPreparation =
 export type AgentSessionMutationRequest<TValue> = {
   store: AgentSessionRecordStore
   adapter: StructuredAgentSessionAdapter
+  logger: StructuredAgentSessionLogger
   callerKey: string
   envelope: AgentSessionMutationEnvelope
   plan: MutationPlan<TValue>
@@ -127,7 +129,7 @@ export async function admitAndRunAgentSessionMutation<TValue>(
     admitted = await request.store.admitMutationOperation(operation)
   } catch (error) {
     if (plan.runsWithoutLedgerRow) {
-      admitted = admitWithoutLedgerRow(request.store, operation, error)
+      admitted = admitWithoutLedgerRow(request, operation, error)
       ledgerRowWritten = false
     } else if (
       isAgentSessionRefusalError(error) ||
@@ -198,13 +200,14 @@ export async function admitAndRunAgentSessionMutation<TValue>(
 
 /** The committed ledger's admission, placing nothing: a failed commit left memory as it was. */
 function admitWithoutLedgerRow(
-  store: AgentSessionRecordStore,
+  { store, logger }: Pick<AgentSessionMutationRequest<unknown>, 'store' | 'logger'>,
   operation: AgentSessionMutationOperationAdmission,
   error: unknown
 ): AgentSessionMutationOperationDecision {
-  console.warn("[agent-session] Stop's ledger row skipped:", {
+  logger.warn("writing Stop's ledger row failed; Stop runs without it", {
+    scope: 'stop-ledger-row',
     sessionId: operation.envelope.sessionId,
-    error: error instanceof Error ? error.message : String(error)
+    error
   })
   const evaluated = store.evaluateMutationOperation(operation)
   if (!evaluated) {
@@ -231,6 +234,7 @@ function turnContext<TValue>(
     journal,
     fence,
     adapter: request.adapter,
+    logger: request.logger,
     ...(persistedOptions ? { persistedOptions } : {}),
     persistOptions: (options) =>
       request.store
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-mutation-context.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-mutation-context.ts
index 73b47f1fe6e..01059d67ceb 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-mutation-context.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-mutation-context.ts
@@ -55,6 +55,7 @@ export function mutateStructuredAgentSession<TValue>(
     admitAndRunAgentSessionMutation({
       store: context.deps.store,
       adapter: context.deps.adapter,
+      logger: context.deps.logger,
       callerKey: caller.callerKey,
       envelope,
       plan,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-operation-settlement.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-operation-settlement.test.ts
index 71750505fef..50c887c85df 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-operation-settlement.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-operation-settlement.test.ts
@@ -17,9 +17,11 @@ import {
 } from './structured-agent-session-host-test-data'
 import type { AgentSessionTurnContext } from './structured-agent-session-turns'
 import { sendPlan } from './structured-agent-session-mutation-plans'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 async function context(): Promise<AgentSessionTurnContext> {
   return {
+    logger: createStructuredAgentSessionLogger(),
     sessionId: SESSION,
     journal: await journals.open({
       identity: {
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-operation-settlement.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-operation-settlement.ts
index e4675bfefb1..24de6ff708b 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-operation-settlement.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-operation-settlement.ts
@@ -52,14 +52,23 @@ export async function runSettledAgentSessionMutation<TValue>(input: {
     if (input.plan.markUnknownBeforeRun && error instanceof AgentSessionPreDispatchError) {
       throw error
     }
+    const { logger, sessionId } = input.context
     try {
       await settle({ status: 'unknown' })
     } catch {
       // Bookkeeping must not replace the operation's proof of whether dispatch began.
-      console.warn('[structured-agent-session] operation uncertainty persistence failed')
+      logger.warn('recording an operation as unknown failed', {
+        scope: 'operation-unknown-settlement',
+        sessionId,
+        operationId: input.envelope.clientOperationId
+      })
     }
     if (outcome && !outcome.ok) {
-      console.warn('[structured-agent-session] refused operation settlement failed')
+      logger.warn('recording a refused operation failed', {
+        scope: 'operation-refused-settlement',
+        sessionId,
+        operationId: input.envelope.clientOperationId
+      })
       return outcome
     }
     throw error
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-operation-start-refusal.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-operation-start-refusal.test.ts
index 7700a616b38..47aecdaa00c 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-operation-start-refusal.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-operation-start-refusal.test.ts
@@ -6,14 +6,16 @@ import type { AgentSessionRecord } from '../../../shared/agent-session-record'
 import type { StructuredAgentSessionAttachContext } from './structured-agent-session-attach-context'
 import { ensureStructuredAgentSessionAgentForOperation } from './structured-agent-session-agent-start'
 import { recordStructuredAgentSessionOptionIntent } from './structured-agent-session-options-read'
+import { recordingStructuredAgentSessionLogger } from './structured-agent-session-logger-test-support'
 
 const SESSION = 'session-1'
 
 describe('an operation whose agent start throws', () => {
   it('is refused as a failed restart, with the error only in the log', async () => {
-    const warn = vi.spyOn(console, 'warn').mockImplementation(() => {})
+    const log = recordingStructuredAgentSessionLogger()
     const cause = new Error('EACCES: permission denied, open /Users/me/.orca/leases.json')
     const context = {
+      deps: { logger: log.logger },
       sessions: new Map(),
       reconcileLeases: () => Promise.reject(cause)
     }
@@ -31,8 +33,9 @@ describe('an operation whose agent start throws', () => {
         message: "The agent couldn't restart."
       }
     })
-    expect(warn).toHaveBeenCalledWith(expect.stringContaining('starting the agent'), cause)
-    warn.mockRestore()
+    expect(log.entries.map((entry) => entry.fields)).toEqual([
+      { scope: 'operation-agent-start', sessionId: SESSION, error: cause }
+    ])
   })
 })
 
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-option-settlement.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-option-settlement.test.ts
index aa7b8a17295..a544e9e1761 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-option-settlement.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-option-settlement.test.ts
@@ -21,6 +21,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 const DEFAULT_MODEL = 'gpt-default'
@@ -124,6 +125,7 @@ beforeEach(async () => {
   store = await openTestAgentSessionRecordStore(root)
   router = adapter()
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: router,
     journalDatabase: openTestJournalHostDatabase(root),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-options-read.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-options-read.ts
index 106998ccfed..e17d5ddf074 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-options-read.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-options-read.ts
@@ -117,7 +117,7 @@ export async function readStructuredAgentSessionOptions(
   const { adapter, store } = context.deps
   const live = await context.serialize(sessionId, async () => {
     const session = await context.openConversation(sessionId).catch((error: unknown) => {
-      throw journalOpenReadRefusal(error)
+      throw journalOpenReadRefusal(error, context.deps.logger, sessionId)
     })
     const child = session?.child
     if (!child) {
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-owed-work-release.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-owed-work-release.test.ts
index 24e9dc66f44..8b2586a9ccb 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-owed-work-release.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-owed-work-release.test.ts
@@ -32,6 +32,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 const SWEEP_MS = 5
@@ -93,6 +94,7 @@ beforeEach(async () => {
   })
   store = await openTestAgentSessionRecordStore(root)
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: Object.assign(adapter, { supportsCreate: () => true }),
     journalDatabase: openTestJournalHostDatabase(root),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-pre-spawn-first-answer.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-pre-spawn-first-answer.test.ts
index db9406785f8..1e171e64199 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-pre-spawn-first-answer.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-pre-spawn-first-answer.test.ts
@@ -17,6 +17,7 @@ import {
 import { openTestAttachConversation } from './structured-agent-session-attach-test-conversation'
 import { performAttach } from './structured-agent-session-attach-flow'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const NOW = 1_800_000_000_000
 const SESSION = 'session-alpha'
@@ -82,6 +83,7 @@ async function firstAnswerAndReplay(thrown: AgentSessionPreSpawnError) {
   const input = {
     store,
     adapter,
+    logger: createStructuredAgentSessionLogger(),
     journalDatabase: openTestJournalHostDatabase(root),
     openConversation: openTestAttachConversation(openTestJournalHostDatabase(root)),
     authority: {
@@ -157,8 +159,11 @@ describe('a create that fails before any process spawns', () => {
     }
     // What failed is kept for the log.
     expect(warn).toHaveBeenCalledWith(
-      '[agent-session] provider start failed:',
-      expect.objectContaining({ message: raw })
+      '[agent-session] provider-start: starting the provider failed',
+      expect.objectContaining({
+        scope: 'provider-start',
+        error: expect.objectContaining({ message: raw })
+      })
     )
   })
 
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-processless-reservation.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-processless-reservation.test.ts
index 9df12ea96fd..c45ceac238c 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-processless-reservation.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-processless-reservation.test.ts
@@ -15,6 +15,7 @@ import {
 import { openTestAttachConversation } from './structured-agent-session-attach-test-conversation'
 import { performAttach } from './structured-agent-session-attach-flow'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const NOW = 1_800_000_000_000
 const SESSION = 'session-alpha'
@@ -82,6 +83,7 @@ describe('processless structured session reservation', () => {
 
     await expect(
       performAttach({
+        logger: createStructuredAgentSessionLogger(),
         store,
         adapter,
         openConversation: openTestAttachConversation(openTestJournalHostDatabase(root!)),
@@ -126,6 +128,7 @@ describe('processless structured session reservation', () => {
       }))
     } as unknown as StructuredAgentSessionAdapter
     const input = {
+      logger: createStructuredAgentSessionLogger(),
       store,
       adapter,
       journalDatabase: openTestJournalHostDatabase(root),
@@ -163,6 +166,7 @@ describe('processless structured session reservation', () => {
     const acquire = vi.fn<StructuredAgentSessionAdapter['acquire']>()
     const adapter = { supportsCreate, acquire } as unknown as StructuredAgentSessionAdapter
     const input = {
+      logger: createStructuredAgentSessionLogger(),
       store,
       adapter,
       journalDatabase: openTestJournalHostDatabase(root),
@@ -215,6 +219,7 @@ describe('processless structured session reservation', () => {
 
     await expect(
       performAttach({
+        logger: createStructuredAgentSessionLogger(),
         store,
         adapter,
         openConversation: openTestAttachConversation(openTestJournalHostDatabase(root!)),
@@ -280,6 +285,7 @@ describe('processless structured session reservation', () => {
       releaseAcquisition: vi.fn(async () => true)
     } as unknown as StructuredAgentSessionAdapter
     const input = {
+      logger: createStructuredAgentSessionLogger(),
       store,
       adapter,
       journalDatabase: openTestJournalHostDatabase(root),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-prompt-cancel.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-prompt-cancel.test.ts
index 1dd8fb73416..8d67ba0aa7c 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-prompt-cancel.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-prompt-cancel.test.ts
@@ -11,6 +11,7 @@ import {
   type StructuredAgentSessionAdapter
 } from './structured-agent-session-adapter'
 import { performCancel, type AgentSessionTurnContext } from './structured-agent-session-turns'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 import { cancelStructuredAgentSessionPrompt } from './structured-agent-session-prompt-cancel'
 import type { AgentSessionPromptCancelRoute } from './structured-agent-session-adapter-stop'
 
@@ -81,6 +82,7 @@ function context(
   flushStreamedEvents: () => Promise<void>
 ): AgentSessionTurnContext {
   return {
+    logger: createStructuredAgentSessionLogger(),
     sessionId: 'session-1',
     journal,
     fence: 1,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-provider-child-record.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-provider-child-record.test.ts
index 230709e5d21..e387d2a5e99 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-provider-child-record.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-provider-child-record.test.ts
@@ -40,6 +40,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 const CHAT_CLOSED = agentSessionFailureWords(agentSessionFailureFact('chatClosed'), {
@@ -83,6 +84,7 @@ const spawnStartingChild: StructuredAgentSessionAdapter['acquire'] = async (inpu
 
 function startHost(): void {
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: {
       acquire,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-provider-restore.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-provider-restore.test.ts
index 411e148c586..de2951a6292 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-provider-restore.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-provider-restore.test.ts
@@ -16,6 +16,7 @@ import {
 import { agentSessionFailureFact } from '../../../shared/agent-session-failure'
 import { agentSessionFailureWords } from '../../../shared/agent-session-failure-words'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CLAUDE_SESSION = 'claude-session'
 const hosts: StructuredAgentSessionHost[] = []
@@ -56,6 +57,7 @@ function createHost(
   probeOwner?: StructuredAgentSessionHost['deps']['probeOwner']
 ): StructuredAgentSessionHost {
   const host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: claudeAdapter(),
     journalDatabase: openTestJournalHostDatabase(root),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-provider-started.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-provider-started.test.ts
index f5e0e14b09f..2922c3fdb2e 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-provider-started.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-provider-started.test.ts
@@ -23,6 +23,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 const INIT_DELAY_MS = 40
@@ -75,6 +76,7 @@ beforeEach(async () => {
   })
   store = await openTestAgentSessionRecordStore(root)
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     // The production router is what declares create support; the bare adapter only knows locations.
     adapter: Object.assign(adapter, { supportsCreate: () => true }),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-provider-started.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-provider-started.ts
index 8f3c0390aaa..acc2e6488c3 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-provider-started.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-provider-started.ts
@@ -24,7 +24,6 @@ export type StructuredAgentSessionProviderStartedContext = {
   serialize: <T>(sessionId: string, task: () => Promise<T>) => Promise<T>
   now: () => number
   publishStatus?: (sessionId: string) => void
-  onBarrierError: (sessionId: string, error: unknown) => void
 }
 
 export function settleStructuredAgentSessionProviderStarted(
@@ -46,7 +45,11 @@ export function settleStructuredAgentSessionProviderStarted(
     try {
       await persistStartedOptions(context, event)
     } catch (error) {
-      context.onBarrierError(event.sessionId, error)
+      context.deps.logger.warn('recording what a started provider reported failed', {
+        scope: 'provider-started-options',
+        sessionId: event.sessionId,
+        error
+      })
     } finally {
       context.publishStatus?.(event.sessionId)
     }
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-queued-message-rig.test-fixture.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-queued-message-rig.test-fixture.ts
index d63af3ba7d2..a9a1089cc1c 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-queued-message-rig.test-fixture.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-queued-message-rig.test-fixture.ts
@@ -26,6 +26,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 export const QUEUED_RIG_CALLER = { callerKey: 'client-1' }
 
@@ -54,6 +55,7 @@ export async function createQueuedMessageTestRig() {
   let events: StructuredAgentSessionEventSink | undefined
   const store = await openTestAgentSessionRecordStore(root)
   const host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: {
       acquire: async ({ fence, spawnToken, events: sink }) => {
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-queued-messages.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-queued-messages.ts
index b6d9d2a90be..856134f04a9 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-queued-messages.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-queued-messages.ts
@@ -30,6 +30,7 @@ import {
   structuredAgentSessionHostInstance,
   structuredQueuePause
 } from './structured-agent-session-queued-pause'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 /** Budget at accept, in the send schema's own unit (`Buffer.byteLength` of the
  *  serialized blocks); refused readably rather than trimmed. */
@@ -263,7 +264,7 @@ export type QueuedMessageDrainDeps = {
   conversationFence: (sessionId: string) => number
   /** The consumed submission is ordinary #22821 work from here on. */
   wakeDelivery: (sessionId: string) => void
-  onError: (sessionId: string, error: unknown) => void
+  logger: StructuredAgentSessionLogger
 }
 
 /**
@@ -312,7 +313,11 @@ export class StructuredAgentSessionQueuedMessageDrain {
       })
       .catch((error: unknown) => {
         this.scheduled.delete(sessionId)
-        this.deps.onError(sessionId, error)
+        this.deps.logger.warn('draining queued messages failed', {
+          scope: 'queued-drain',
+          sessionId,
+          error
+        })
       })
   }
 
@@ -326,7 +331,11 @@ export class StructuredAgentSessionQueuedMessageDrain {
     if (journal.queuedMessages.settlementOwed() || journal.queuedMessages.deliveredByEchoOwed()) {
       // A live per-row hook was skipped; heal now, before a draft sends, rather than at reopen.
       await journal.queuedMessages.settleOwed().catch((error: unknown) => {
-        this.deps.onError(sessionId, error)
+        this.deps.logger.warn('settling owed queued-message bookkeeping failed', {
+          scope: 'queued-settle-owed',
+          sessionId,
+          error
+        })
       })
     }
     const next = oldestActionableQueuedMessage(journal)
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-queued-mutations.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-queued-mutations.ts
index 5b7f4bdf16c..288848a96a6 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-queued-mutations.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-queued-mutations.ts
@@ -127,9 +127,11 @@ export async function carryQueuedMessagesToClearReplacement(
       operationId: input.operationId
     })
   } catch (error) {
-    console.warn("[agent-session] /clear's queued-draft carry skipped:", {
+    ctx.logger.warn("carrying queued drafts to /clear's replacement failed", {
+      scope: 'clear-queued-carry',
       sessionId: ctx.sessionId,
-      error: error instanceof Error ? error.message : String(error)
+      replacementSessionId: input.replacementSessionId,
+      error
     })
   }
 }
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-queued-pause.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-queued-pause.ts
index 1428de75fe6..f96716d0304 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-queued-pause.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-queued-pause.ts
@@ -15,6 +15,7 @@ import { randomUUID } from 'node:crypto'
 import type { AgentSessionQueuePause } from '../../../shared/agent-session-wire'
 import type { AgentSessionJournal } from '../agent-session-journal/journal-store'
 import type { QueuePauseFact } from '../agent-session-journal/queued-message-pause-table'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 /** A per-process id, minted once per host process like the runtime's own
  *  `runtimeId` (`orca-runtime-runtime-id.ts`); a draft written by another
@@ -74,7 +75,8 @@ export function structuredQueuePause(journal: PauseJournal): AgentSessionQueuePa
  */
 export async function retireEndedQueuePause(
   sessionId: string,
-  journal: PauseJournal
+  journal: PauseJournal,
+  logger: StructuredAgentSessionLogger
 ): Promise<void> {
   try {
     const stop = journal.queuedMessages.pause()
@@ -88,9 +90,10 @@ export async function retireEndedQueuePause(
       adoptInto: adopt ? hostInstance : null
     })
   } catch (error) {
-    console.warn("[agent-session] a started turn's queue-pause retirement skipped:", {
+    logger.warn('retiring a queue pause a started turn ended failed', {
+      scope: 'queue-pause-retirement',
       sessionId,
-      error: error instanceof Error ? error.message : String(error)
+      error
     })
   }
 }
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-queued-stop.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-queued-stop.ts
index 16a9b4aeaf7..c715f5accd9 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-queued-stop.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-queued-stop.ts
@@ -59,8 +59,10 @@ export async function runStopWithQueuePause<TValue>(
 }
 
 function report(ctx: AgentSessionTurnContext, step: string, error: unknown): void {
-  console.warn(`[agent-session] Stop's ${step} skipped:`, {
+  ctx.logger.warn(`Stop's ${step} failed`, {
+    scope: 'stop-queued-bookkeeping',
     sessionId: ctx.sessionId,
-    error: error instanceof Error ? error.message : String(error)
+    step,
+    error
   })
 }
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-queued-wiring.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-queued-wiring.ts
index 2b193d5cb82..f3861f97166 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-queued-wiring.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-queued-wiring.ts
@@ -15,6 +15,7 @@ import {
   resumeStructuredAgentQueue,
   sendQueuedStructuredAgentMessage
 } from './structured-agent-session-queued-mutations'
+import { deferredStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 /** `sessions` are the live conversations (their `touch` is the idle sweep's activity renewal,
  *  which the drain's schedule rides); everything else comes from the host's mutation context,
@@ -33,7 +34,8 @@ export function wireStructuredAgentSessionQueuedMessages(
     conversationFence: (sessionId) =>
       structuredAgentSessionConversationFence(context().deps.store, sessionId),
     wakeDelivery: (sessionId) => context().wakeDelivery(sessionId),
-    onError: (sessionId, error) => context().deps.onEventSinkError?.({ sessionId, error })
+    // Read lazily, like the rest of this wiring: the host's deps are not assigned yet.
+    logger: deferredStructuredAgentSessionLogger(() => context().deps.logger)
   })
   return {
     drain,
@@ -44,7 +46,7 @@ export function wireStructuredAgentSessionQueuedMessages(
       sessions.touch(sessionId)
       const journal = sessions.get(sessionId)?.journal
       if (journal && !journal.isReadOnly) {
-        void retireEndedQueuePause(sessionId, journal)
+        void retireEndedQueuePause(sessionId, journal, context().deps.logger)
       }
       drain.schedule(sessionId)
     },
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-read-restore.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-read-restore.test.ts
index 83238e95d74..945f2cefbad 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-read-restore.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-read-restore.test.ts
@@ -18,6 +18,7 @@ import {
   openTestJournalHostDatabase
 } from '../agent-session-journal/journal-host-database-test-support'
 import { restoreStructuredAgentSessionRead } from './structured-agent-session-read-restore'
+import { recordingStructuredAgentSessionLogger } from './structured-agent-session-logger-test-support'
 
 const SESSION_ID = 'codex_read_restore_fixture'
 const WORKSPACE_ID = 'repo-1::/tmp/workspace'
@@ -55,7 +56,8 @@ let journalRoot: string
 const openDeps = () => ({
   store,
   journalDatabase: openTestJournalHostDatabase(journalRoot),
-  adapter: {}
+  adapter: {},
+  logger: recordingStructuredAgentSessionLogger().logger
 })
 const opened: AgentSessionJournal[] = []
 
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-readable-restorer.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-readable-restorer.test.ts
index 09cab618ab9..8f110c3e69a 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-readable-restorer.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-readable-restorer.test.ts
@@ -15,6 +15,7 @@ vi.mock('./structured-agent-session-restart-restore', () => ({
 }))
 
 import { StructuredAgentSessionReadableRestorer } from './structured-agent-session-readable-restorer'
+import { recordingStructuredAgentSessionLogger } from './structured-agent-session-logger-test-support'
 
 // The restore pool is mocked; the host database only fills the deps' shape.
 const stateDirectory = mkdtempSync(join(tmpdir(), 'orca-readable-restorer-'))
@@ -36,7 +37,8 @@ describe('StructuredAgentSessionReadableRestorer', () => {
       openDeps: {
         store: { getRecord: () => null, listRecords: () => records },
         journalDatabase: openTestJournalHostDatabase(stateDirectory),
-        adapter: {}
+        adapter: {},
+        logger: recordingStructuredAgentSessionLogger().logger
       },
       supportsRecord: () => true,
       reconcile: async () => true,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-recovered-turn-clock.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-recovered-turn-clock.test.ts
index 538fb0b9dbc..a277d9a3d4c 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-recovered-turn-clock.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-recovered-turn-clock.test.ts
@@ -34,6 +34,7 @@ import {
 import { StructuredAgentSessionStatusFeed } from './structured-agent-session-status-feed'
 import { indexedStatusFeedSession } from './structured-agent-session-status-feed-test-session'
 import { StructuredAgentSessionTurnCompletionFeed } from './structured-agent-session-turn-completion-feed'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const SESSION = 'recovered-turn-session'
 const THREAD = 'thread-1'
@@ -81,6 +82,7 @@ async function sessionWithRunningTurn() {
   const server = new AgentHookServer()
   const sessions = new Map([[SESSION, indexedStatusFeedSession({ journal })]])
   const feed = new StructuredAgentSessionStatusFeed({
+    logger: createStructuredAgentSessionLogger(),
     sessions,
     getRecord: () => null,
     now: () => clock,
@@ -129,7 +131,7 @@ async function sessionWithRunningTurn() {
 function settleDeadGeneration(
   journal: AgentSessionJournal,
   verdict: StructuredAgentSessionTurnVerdict
-): Promise<boolean> {
+): ReturnType<typeof settleStructuredAgentSessionDeadGeneration> {
   return settleStructuredAgentSessionDeadGeneration({
     journal,
     sessionId: SESSION,
@@ -160,7 +162,7 @@ describe('a turn recovery settled after its host went away', () => {
     async (_label, verdict, outcome, mark) => {
       const session = await sessionWithRunningTurn()
       session.recoverAt(RECOVERED)
-      expect(await settleDeadGeneration(session.journal, verdict)).toBe(true)
+      expect(await settleDeadGeneration(session.journal, verdict)).toEqual({ ok: true })
       session.publish()
 
       expect(session.summaries.at(-1)).toMatchObject({
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-recovery-exits.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-recovery-exits.test.ts
index f69fbad1031..228fa21fbc2 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-recovery-exits.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-recovery-exits.test.ts
@@ -22,6 +22,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 
@@ -81,6 +82,7 @@ function adapter(): StructuredAgentSessionAdapter {
 
 function openHost(overrides: Partial<StructuredAgentSessionHostDeps> = {}): void {
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: adapter(),
     journalDatabase: openTestJournalHostDatabase(root),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-refusal-retry.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-refusal-retry.test.ts
index 83082bf923a..d5899c794e3 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-refusal-retry.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-refusal-retry.test.ts
@@ -29,6 +29,7 @@ import {
   hostTestMessage
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 const METHODS = ['agentSession.setOption', 'agentSession.send'] as const
@@ -88,6 +89,7 @@ async function createHarness(options: { attached?: boolean } = {}) {
     setOption
   }
   const host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter,
     journalDatabase: openTestJournalHostDatabase(root),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-resolved-append.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-resolved-append.test.ts
index d3c15de933c..4b06198e373 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-resolved-append.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-resolved-append.test.ts
@@ -12,6 +12,7 @@ import {
   type StructuredAgentSessionRevisionResolver
 } from './structured-agent-session-event-sink'
 import { estimateStructuredAgentSessionItemBytes } from './structured-agent-session-event-sink-estimate'
+import { testEventSinkLogging } from './structured-agent-session-logger-test-support'
 
 const ROW: AgentJournalItemIdentity = { provider: 'orca', clientMessageId: 'row' }
 
@@ -61,7 +62,7 @@ const appendSuffix =
 describe('resolved revisions', () => {
   it('reads the row as the journal holds it when each queued revision runs', async () => {
     const rows = new Map<string, AgentJournalItemBody>()
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
     const bytes = estimateStructuredAgentSessionItemBytes(ROW, text('abc'))
     for (const suffix of ['a', 'b', 'c']) {
       expect(
@@ -81,7 +82,7 @@ describe('resolved revisions', () => {
 
   it('skips a revision that resolves to nothing', async () => {
     const rows = new Map<string, AgentJournalItemBody>()
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
     deferred.sink.tryReviseResolvedItem?.(1_000, () => null, {
       turnScope: AGENT_JOURNAL_THREAD_SCOPE
     })
@@ -93,7 +94,7 @@ describe('resolved revisions', () => {
 
   it('publishes a revision in the operation that writes it, within the same reservation', async () => {
     const rows = new Map<string, AgentJournalItemBody>()
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
     const bytes = estimateStructuredAgentSessionItemBytes(ROW, text('a'))
     deferred.sink.tryReviseResolvedItemAndPublish?.(bytes, appendSuffix('a'), {
       turnScope: AGENT_JOURNAL_THREAD_SCOPE
@@ -114,7 +115,7 @@ describe('resolved revisions', () => {
 
   it('refuses a resolved write larger than the reservation it was admitted with', async () => {
     const rows = new Map<string, AgentJournalItemBody>()
-    const deferred = createDeferredStructuredAgentSessionEventSink()
+    const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
     const bytes = estimateStructuredAgentSessionItemBytes(ROW, text('a'))
     deferred.sink.tryReviseResolvedItem?.(
       bytes,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-rest-test-rig.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-rest-test-rig.ts
index e441a156b49..0045684ccb3 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-rest-test-rig.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-rest-test-rig.ts
@@ -33,6 +33,7 @@ import {
 } from './structured-agent-session-host-test-data'
 import { STRUCTURED_AGENT_SESSION_IDLE_MS } from './structured-agent-session-idle-sweep'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 export const REST_TEST_CALLER = { callerKey: 'client-1' }
 export const IDLE_MS = STRUCTURED_AGENT_SESSION_IDLE_MS
@@ -160,6 +161,7 @@ export async function createRestTestRig(
   }
   const hostFor = (overrides: Partial<StructuredAgentSessionHostDeps>) =>
     new StructuredAgentSessionHost({
+      logger: createStructuredAgentSessionLogger(),
       store,
       adapter: {
         ...adapter,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-cap.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-cap.test.ts
index 9ded5b54d98..155785ae35e 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-cap.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-cap.test.ts
@@ -13,6 +13,7 @@ import {
   StructuredAgentSessionResumeAdmission
 } from './structured-agent-session-restart-resume-runner'
 import { marker } from './structured-agent-session-restart-resume-test-harness'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 type Handover = { dispatchState: string; reason?: string | null } | undefined
 
@@ -36,7 +37,7 @@ it('holds each slot from accept until handover or rejection, and frees it when t
     },
     awaitSettlement: async () => ({ dispatchState: 'accepted' }),
     note: async () => undefined,
-    onNoteFailed: () => undefined
+    logger: createStructuredAgentSessionLogger()
   })
   const sessions = Array.from({ length: 8 }, (_, index) => `session-${index}`)
   const outcomes = resumeStructuredAgentSessionsFromRestart(
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-continuation.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-continuation.test.ts
index 0fe36994cd7..973d7758358 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-continuation.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-continuation.test.ts
@@ -10,6 +10,7 @@ import {
   startStructuredAgentSessionContinuation,
   type StructuredAgentSessionContinuationDeps
 } from './structured-agent-session-restart-continuation'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 /** The whole continuation: handed over, then its verdict. */
 async function continueStructuredAgentSessionAfterRestart(
@@ -45,7 +46,7 @@ function dependencies(
         : undefined
     ),
     note: vi.fn(async () => undefined),
-    onNoteFailed: vi.fn()
+    logger: createStructuredAgentSessionLogger()
   }
 }
 
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-continuation.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-continuation.ts
index 8038e90e1fc..27c09bc2bbe 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-continuation.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-continuation.ts
@@ -31,6 +31,7 @@ import {
 import { AgentSessionPreDispatchError } from './structured-agent-session-operation-settlement'
 import { restartContinuationEnvelope } from './structured-agent-session-restart-continuation-envelope'
 import type { AgentSessionResumeMarker } from '../../../shared/agent-session-resume-marker'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 /**
  * All four dispatch states are preserved, never collapsed into transport success.
@@ -71,7 +72,7 @@ export type StructuredAgentSessionContinuationHost = {
     sessionId: string,
     clientMessageId: string
   ) => Promise<{ value: AgentSessionSendResult } | undefined>
-  onNoteFailed: (sessionId: string, error: unknown) => void
+  logger: StructuredAgentSessionLogger
   now: () => number
   /** Whether the marker is still an offer. Asked at acceptance, inside the session lock, so the
    *  first message accepted since the restart decides: the user's, or this continuation. */
@@ -103,7 +104,7 @@ export function restartContinuationDeps(
       agentSessionSendSubmission(
         (await host.awaitSendHandedOver(sessionId, clientMessageId))?.value
       ),
-    onNoteFailed: host.onNoteFailed,
+    logger: host.logger,
     note: restartNoteWriter(host)
   }
 }
@@ -185,9 +186,9 @@ export type StructuredAgentSessionContinuationDeps = {
   /** Records a host-authored journal note: that this send was Orca's, not the user's, or that the
    *  chat did not carry on. `tone` is a display hint older clients render as plain text. */
   note: (sessionId: string, text: string, tone?: 'error' | 'warning') => Promise<void>
-  /** Reports a note that could not be written. The note is best effort, but its failure is not
-   *  allowed to be silent — a swallowed append is how this regressed unnoticed once already. */
-  onNoteFailed: (sessionId: string, error: unknown) => void
+  /** Where a note that could not be written is reported. The note is best effort, but its failure
+   *  is not allowed to be silent — a swallowed append is how this regressed unnoticed once already. */
+  logger: StructuredAgentSessionLogger
 }
 
 /** A continuation handed to its agent, or already decided. */
@@ -232,7 +233,7 @@ export async function startStructuredAgentSessionContinuation(
 }
 
 async function noteOutcome(
-  deps: Pick<StructuredAgentSessionContinuationDeps, 'note' | 'onNoteFailed'>,
+  deps: Pick<StructuredAgentSessionContinuationDeps, 'note' | 'logger'>,
   sessionId: string,
   result: StructuredAgentSessionContinuationOutcome
 ): Promise<void> {
@@ -241,8 +242,8 @@ async function noteOutcome(
     // carry on. Best effort — losing it must not turn a delivered continuation into a failure.
     try {
       await deps.note(sessionId, AGENT_SESSION_RESTART_CONTINUATION_NOTE)
-    } catch (error) {
-      deps.onNoteFailed(sessionId, error)
+    } catch {
+      reportNoteFailed(deps, sessionId)
     }
   } else {
     await noteNotContinued(
@@ -260,7 +261,7 @@ async function noteOutcome(
 /** The chat itself carries the failure, so it survives the toast, a dismissed record and a restart,
  *  and the user's next message is what moves past it. */
 async function noteNotContinued(
-  deps: Pick<StructuredAgentSessionContinuationDeps, 'note' | 'onNoteFailed'>,
+  deps: Pick<StructuredAgentSessionContinuationDeps, 'note' | 'logger'>,
   sessionId: string,
   outcome: 'refused' | 'not-connected' | 'unconfirmed'
 ): Promise<void> {
@@ -274,8 +275,8 @@ async function noteNotContinued(
             : AGENT_SESSION_RESTART_NOT_CONNECTED_NOTE,
           'error'
         ))
-  } catch (error) {
-    deps.onNoteFailed(sessionId, error)
+  } catch {
+    reportNoteFailed(deps, sessionId)
   }
 }
 
@@ -295,7 +296,10 @@ async function sendContinuation(
       throw error
     }
     // Persistence can fail after dispatch; a thrown send is not proof of non-delivery.
-    console.warn('[structured-agent-session] restart continuation send failed')
+    deps.logger.warn('sending a restart continuation failed', {
+      scope: 'restart-continuation-send',
+      sessionId
+    })
     return null
   })
   if (!sent) {
@@ -360,3 +364,14 @@ function verdictOf(
     ? { sessionId, outcome: 'continued' }
     : { sessionId, outcome: 'unknown' }
 }
+
+/** Without the error: a failed append can carry the chat's private recovery payload. */
+function reportNoteFailed(
+  deps: Pick<StructuredAgentSessionContinuationDeps, 'logger'>,
+  sessionId: string
+): void {
+  deps.logger.warn('writing a restart continuation note failed', {
+    scope: 'restart-continuation-note',
+    sessionId
+  })
+}
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-failure-ledger.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-failure-ledger.ts
index ee769b9e8c3..63722d1737c 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-failure-ledger.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-failure-ledger.ts
@@ -31,6 +31,7 @@ import {
   type StructuredAgentSessionResumeOutcome
 } from './structured-agent-session-restart-resume-runner'
 import { RESTART_CONTINUATION_SUPERSEDED } from './structured-agent-session-restart-continuation'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 type FailureCapsule = Pick<
   AgentSessionRecoveryCapsule,
@@ -79,6 +80,7 @@ export function createStructuredAgentSessionRestartFailureLedger(deps: {
   retryable: (marker: AgentSessionResumeMarker) => boolean
   /** Makes the failed chats readable here, so `retryable` reads each one's journal. */
   reveal: (markers: readonly AgentSessionResumeMarker[]) => Promise<void>
+  logger: StructuredAgentSessionLogger
   now: () => number
   /** The capsule's single mutation lane, shared with the offer's own operations. */
   enqueue: <T>(operation: () => Promise<T>) => Promise<T>
@@ -88,7 +90,9 @@ export function createStructuredAgentSessionRestartFailureLedger(deps: {
       return (await deps.capsule?.listFailed(deps.now())) ?? []
     } catch {
       // Recovery is advisory; a malformed capsule must not make ordinary chat actions unusable.
-      console.warn('[structured-agent-session] reading recovery capsule failed')
+      deps.logger.warn('reading restart failures from the recovery capsule failed', {
+        scope: 'recovery-capsule-read'
+      })
       return []
     }
   }
@@ -176,21 +180,30 @@ export function createStructuredAgentSessionRestartFailureLedger(deps: {
     await deps
       .enqueue(() => capsule.completeResume(operationId, completed, deps.now()))
       .catch(() => {
-        console.warn('[structured-agent-session] restart offer completion failed')
+        deps.logger.warn('completing a restart offer failed', {
+          scope: 'restart-offer-complete',
+          operationId
+        })
       })
     // Filed before the rollback so a failure the user must act on is never reopened as an offer
     // that would silently re-run it.
     await deps
       .enqueue(() => capsule.failResume(operationId, failures, deps.now()))
       .catch(() => {
-        console.warn('[structured-agent-session] restart failure record failed')
+        deps.logger.warn('recording a restart failure failed', {
+          scope: 'restart-failure-record',
+          operationId
+        })
       })
     // This only reopens rows still owned by this operation. Rows removed by completeResume stay
     // removed, even when the write of a later bookkeeping step fails.
     await deps
       .enqueue(() => capsule.rollbackResume(operationId, deps.now()))
       .catch(() => {
-        console.warn('[structured-agent-session] restart offer rollback failed')
+        deps.logger.warn('rolling back a restart offer failed', {
+          scope: 'restart-offer-rollback',
+          operationId
+        })
       })
   }
 
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-interruption-test-harness.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-interruption-test-harness.ts
index 9bb2173f42f..94746daf3ec 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-interruption-test-harness.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-interruption-test-harness.ts
@@ -34,6 +34,7 @@ import {
   hostTestMessage
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { recordingProductionStructuredAgentSessionLogger } from './structured-agent-session-logger-test-support'
 
 /** Starts the agent explicitly — the attach a client's ensure makes — for a test that needs a
  *  running child before its next step. Nothing else starts one ahead of a send. */
@@ -124,7 +125,9 @@ export async function interruptedRestart(
   const closeSession = vi.fn(async () => true)
   // The relaunch comes after the quit that recorded the offer.
   const clock = { now: NOW + 1 }
+  const log = recordingProductionStructuredAgentSessionLogger()
   const host = new StructuredAgentSessionHost({
+    logger: log.logger,
     store,
     adapter: {
       ...adapter(),
@@ -154,7 +157,7 @@ export async function interruptedRestart(
     await readFile(join(previous.root, AGENT_SESSION_RECOVERY_CAPSULE_FILE), 'utf8')
   )
   const marker = parseAgentSessionResumeMarker(capsule.entries[0]?.marker)
-  return { ...hostTestState(), host, store, closeSession, marker, clock }
+  return { ...hostTestState(), host, store, log, closeSession, marker, clock }
 }
 
 export async function statusNotes(host: StructuredAgentSessionHost) {
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-offer-records.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-offer-records.ts
index f9530039cd4..95c97be63a9 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-offer-records.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-offer-records.ts
@@ -3,6 +3,7 @@
 
 import type { AgentSessionRecoveryCapsule } from '../../runtime/agent-session-recovery-capsule'
 import type { AgentSessionResumeMarker } from '../../../shared/agent-session-resume-marker'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 export type StructuredAgentSessionRestartOfferRecords = {
   /** Every pending offer. Read-only; nothing is spent. */
@@ -23,6 +24,7 @@ export function createStructuredAgentSessionRestartOfferRecords(deps: {
   readFailedMarkers: () => Promise<AgentSessionResumeMarker[]>
   hasSession: (sessionId: string) => boolean
   reveal: (sessionId: string) => Promise<void>
+  logger: StructuredAgentSessionLogger
   now: () => number
   /** The capsule's single mutation lane, shared with the offer's own operations. */
   enqueue: <T>(operation: () => Promise<T>) => Promise<T>
@@ -33,7 +35,9 @@ export function createStructuredAgentSessionRestartOfferRecords(deps: {
     } catch {
       // Recovery is advisory. A malformed capsule must not make ordinary chat actions unusable;
       // the durable bytes stay untouched so an explicit dismissal can remove them.
-      console.warn('[structured-agent-session] reading recovery capsule failed')
+      deps.logger.warn('reading restart offers from the recovery capsule failed', {
+        scope: 'recovery-capsule-read'
+      })
       return []
     }
   }
@@ -69,7 +73,9 @@ export function createStructuredAgentSessionRestartOfferRecords(deps: {
       void deps
         .enqueue(() => capsule.forgetSuperseded(gone, deps.now()))
         .catch(() => {
-          console.warn('[structured-agent-session] pruning superseded restart offers failed')
+          deps.logger.warn('pruning superseded restart offers failed', {
+            scope: 'restart-offer-prune'
+          })
         })
     }
   }
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-offer-withdrawal.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-offer-withdrawal.test.ts
index d36e5702d1d..b155674babf 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-offer-withdrawal.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-offer-withdrawal.test.ts
@@ -29,6 +29,7 @@ import {
   HOST_TEST_SESSION as SESSION,
   hostTestMessage
 } from './structured-agent-session-host-test-data'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 afterEach(() => vi.restoreAllMocks())
 
@@ -450,6 +451,7 @@ describe('reading the chat against where the offer was taken', () => {
       }
     }
     const withdrawal = createStructuredAgentSessionRestartOfferWithdrawal({
+      logger: createStructuredAgentSessionLogger(),
       // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: the fact reads only the journal's cursor and submissions and the child fields given here.
       sessions: new Map([[SESSION, session as never]]),
       now: () => NOW,
@@ -527,6 +529,7 @@ describe('reading the chat against where the offer was taken', () => {
         }
       }
       const withdrawal = createStructuredAgentSessionRestartOfferWithdrawal({
+        logger: createStructuredAgentSessionLogger(),
         // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: the fact reads only the journal's cursor and submissions and the child fields given here.
         sessions: new Map([[SESSION, session as never]]),
         now: () => afterCrash,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-offer-withdrawal.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-offer-withdrawal.ts
index 76d8006d9a1..4924860b05f 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-offer-withdrawal.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-offer-withdrawal.ts
@@ -13,6 +13,7 @@ import type { AgentSessionResumeMarker } from '../../../shared/agent-session-res
 import { isQueuedAgentJournalSubmission } from '../../../shared/agent-session-queued-submission'
 import type { StructuredAgentSessionHostSession } from './structured-agent-session-host-types'
 import { isRestartContinuationOf } from './structured-agent-session-restart-continuation-envelope'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 export type StructuredAgentSessionRestartOfferWithdrawal = ReturnType<
   typeof createStructuredAgentSessionRestartOfferWithdrawal
@@ -26,6 +27,7 @@ export type StructuredAgentSessionRestartOfferSession = Pick<
 export function createStructuredAgentSessionRestartOfferWithdrawal(deps: {
   sessions: ReadonlyMap<string, StructuredAgentSessionRestartOfferSession>
   capsule?: Pick<AgentSessionRecoveryCapsule, 'dismiss'>
+  logger: StructuredAgentSessionLogger
   now: () => number
   /** The capsule's single mutation lane, shared with the offer's own operations. */
   enqueue: <T>(operation: () => Promise<T>) => Promise<T>
@@ -85,7 +87,10 @@ export function createStructuredAgentSessionRestartOfferWithdrawal(deps: {
           )
         )
         .catch(() => {
-          console.warn('[structured-agent-session] withdrawing a restart offer failed')
+          deps.logger.warn('withdrawing a restart offer failed', {
+            scope: 'restart-offer-withdraw',
+            sessionId
+          })
         })
     }
   }
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-ownership.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-ownership.test.ts
index 59ff6958d53..a46551b4500 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-ownership.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-ownership.test.ts
@@ -34,6 +34,7 @@ import {
 } from './structured-agent-session-host-test-data'
 import { agentSessionFailureFact } from '../../../shared/agent-session-failure'
 import { agentSessionFailureWords } from '../../../shared/agent-session-failure-words'
+import { inspect } from 'node:util'
 
 afterEach(() => vi.useRealTimers())
 
@@ -53,7 +54,7 @@ it('publishes continuation attribution to the subscribed chat without another pr
 })
 
 it('reports a failed attribution note without an installed error sink or private details', async () => {
-  const { host } = await interruptedRestart()
+  const { host, log } = await interruptedRestart()
   const append = AgentSessionJournal.prototype.appendItem
   const warning = vi.spyOn(console, 'warn').mockImplementation(() => {})
   const write = vi.spyOn(AgentSessionJournal.prototype, 'appendItem').mockImplementation(function (
@@ -69,8 +70,11 @@ it('reports a failed attribution note without an installed error sink or private
     const result = await host.restartResume.continueAfterRestart([SESSION], 'modal')
     expect(result.continued).toMatchObject([{ outcome: 'continued' }])
     expect(warning).toHaveBeenCalledExactlyOnceWith(
-      '[structured-agent-session] restart continuation attribution failed'
+      '[agent-session] restart-continuation-note: writing a restart continuation note failed',
+      { scope: 'restart-continuation-note', sessionId: SESSION }
     )
+    expect(log.scopes()).toContain('restart-continuation-note')
+    expect(inspect(log.entries, { depth: 8 })).not.toContain('/private/account')
   } finally {
     write.mockRestore()
     warning.mockRestore()
@@ -318,7 +322,7 @@ it('keeps concurrent recovery reads independent and non-destructive', async () =
 })
 
 it('fails closed on corrupt recovery storage while an ordinary send still works', async () => {
-  const { host, root, dispatch } = await interruptedRestart()
+  const { host, root, dispatch, log } = await interruptedRestart()
   await writeFile(join(root, AGENT_SESSION_RECOVERY_CAPSULE_FILE), '{')
   const warning = vi.spyOn(console, 'warn').mockImplementation(() => {})
   expect(await host.restartResume.list()).toEqual([])
@@ -335,9 +339,15 @@ it('fails closed on corrupt recovery storage while an ordinary send still works'
   await vi.waitFor(() => expect(dispatch).toHaveBeenCalledTimes(1))
   // list; the action's read of offers and of failures; the post-action refresh of both. The send
   // cannot withdraw an offer it cannot read either, and says so.
-  const withdrawing = '[structured-agent-session] withdrawing a restart offer failed'
-  await vi.waitFor(() => expect(warning).toHaveBeenLastCalledWith(withdrawing))
-  expect(warning.mock.calls.filter(([message]) => message !== withdrawing)).toHaveLength(5)
+  await vi.waitFor(() =>
+    expect(log.entries.at(-1)).toEqual({
+      level: 'warn',
+      message: 'withdrawing a restart offer failed',
+      fields: { scope: 'restart-offer-withdraw', sessionId: SESSION }
+    })
+  )
+  // Counted before the console's repeat suppression, which prints each repeated read only once.
+  expect(log.scopes().filter((scope) => scope !== 'restart-offer-withdraw')).toHaveLength(5)
   warning.mockRestore()
 })
 
@@ -451,9 +461,12 @@ it('logs teardown capsule publication failure and still releases the provider',
     'agent_session_ownership_unknown'
   )
   expect(warning).toHaveBeenCalledWith(
-    '[structured-agent-session] recording recovery capsule failed'
+    '[agent-session] teardown-recovery-capsule: recording the recovery capsule at teardown failed',
+    { scope: 'teardown-recovery-capsule' }
   )
-  expect(warning.mock.calls.flat().map(String).join(' ')).not.toContain(previous.root)
+  expect(inspect(warning.mock.calls, { depth: 8 })).not.toContain(previous.root)
+  expect(previous.log.scopes()).toContain('teardown-recovery-capsule')
+  expect(inspect(previous.log.entries, { depth: 8 })).not.toContain(previous.root)
   expect(previous.store.getRecord(SESSION)?.lease.claimStatus).toBe('released')
   warning.mockRestore()
   await rm(capsulePath, { recursive: true })
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-reconcile.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-reconcile.ts
index 41dd7913d85..29f0c9f1047 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-reconcile.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-reconcile.ts
@@ -8,6 +8,7 @@ import type { AgentSessionRecord } from '../../../shared/agent-session-record'
 import type { AgentSessionWireRefusal } from '../../../shared/agent-session-wire'
 import type { AgentSessionRecordStore } from '../../runtime/agent-session-record-store'
 import { classifyStoreFailure } from './structured-agent-session-attach'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const MAX_RECONCILIATION_PASSES = 8
 
@@ -53,8 +54,10 @@ export type ReaderBookkeepingFailures = {
   clear: () => void
 }
 
+/** Startup and the read carry on past a failure: the next attach or send reconciles and resolves
+ *  recovery again before it acts. */
 export function reportEachFailureOnce(
-  onFailure: ((failure: unknown) => void) | undefined
+  logger: StructuredAgentSessionLogger
 ): ReaderBookkeepingFailures {
   let reported: string | null = null
   return {
@@ -62,15 +65,10 @@ export function reportEachFailureOnce(
       const key = failureKey(failure)
       if (key !== reported) {
         reported = key
-        try {
-          onFailure?.(failure)
-        } catch (sinkError) {
-          // A throwing sink must not turn the reported failure back into a failed read.
-          console.warn('[structured-agent-session] reporting a lease bookkeeping failure failed', {
-            failure,
-            sinkError
-          })
-        }
+        logger.warn('chat lease bookkeeping for a read failed', {
+          scope: 'lease-reconcile',
+          error: failure
+        })
       }
     },
     clear: () => {
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-restore.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-restore.test.ts
index 4da648576ed..441d4e80626 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-restore.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-restore.test.ts
@@ -18,6 +18,7 @@ vi.mock('./structured-agent-session-read-restore', () => ({
 }))
 
 import { restoreStructuredAgentSessionsOnRestart } from './structured-agent-session-restart-restore'
+import { recordingStructuredAgentSessionLogger } from './structured-agent-session-logger-test-support'
 
 // The restore under test is mocked; the host database only fills the deps' shape.
 const stateDirectory = mkdtempSync(join(tmpdir(), 'orca-restart-restore-'))
@@ -29,7 +30,8 @@ afterAll(() => {
 const NO_OPEN_DEPS = {
   store: { getRecord: () => null, listRecords: () => [] },
   journalDatabase: openTestJournalHostDatabase(stateDirectory),
-  adapter: {}
+  adapter: {},
+  logger: recordingStructuredAgentSessionLogger().logger
 }
 
 describe('restart journal restoration', () => {
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-resume-host.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-resume-host.ts
index af2a0970a6f..ef8481e2b1f 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-resume-host.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-resume-host.ts
@@ -44,6 +44,7 @@ import {
 import type { StructuredAgentSessionRestartResumeSurfaces } from './structured-agent-session-restart-resume-wiring'
 import { createStructuredAgentSessionRestartWitnesses } from './structured-agent-session-restart-witnesses'
 import { structuredAgentSessionConversationFence } from './structured-agent-session-provider-child'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 type LiveSession = StructuredAgentSessionRestartOfferSession
 
@@ -77,6 +78,7 @@ export function createStructuredAgentSessionRestartResume(
     store: AgentSessionRecordStore
     adapter: StructuredAgentSessionAdapter
     recoveryCapsule?: AgentSessionRecoveryCapsule
+    logger: StructuredAgentSessionLogger
   },
   sessions: ReadonlyMap<string, LiveSession>,
   surfaces: StructuredAgentSessionRestartResumeSurfaces
@@ -96,6 +98,7 @@ export function createStructuredAgentSessionRestartResume(
   const withdrawal = createStructuredAgentSessionRestartOfferWithdrawal({
     sessions,
     ...(deps.recoveryCapsule ? { capsule: deps.recoveryCapsule } : {}),
+    logger: deps.logger,
     now: surfaces.now,
     enqueue: enqueueRecoveryOperation
   })
@@ -111,6 +114,7 @@ export function createStructuredAgentSessionRestartResume(
     adapter: deps.adapter,
     retryable: (marker) => derive([marker], 'may-be-held').candidates.length === 1,
     reveal: (markers) => revealMarkers(markers),
+    logger: deps.logger,
     now: surfaces.now,
     enqueue: enqueueRecoveryOperation
   })
@@ -123,6 +127,7 @@ export function createStructuredAgentSessionRestartResume(
       reveal: async (sessionId) => {
         await surfaces.revealSession(sessionId).catch(() => null)
       },
+      logger: deps.logger,
       now: surfaces.now,
       enqueue: enqueueRecoveryOperation
     })
@@ -139,6 +144,7 @@ export function createStructuredAgentSessionRestartResume(
 
   const continuationHost: StructuredAgentSessionContinuationHost = {
     ...surfaces,
+    logger: deps.logger,
     sessions,
     conversationFence: (sessionId) =>
       deps.store.getRecord(sessionId)
@@ -206,7 +212,10 @@ export function createStructuredAgentSessionRestartResume(
         await enqueueRecoveryOperation(() =>
           deps.recoveryCapsule!.rollbackResume(operationId, surfaces.now())
         ).catch(() => {
-          console.warn('[structured-agent-session] restart offer rollback failed')
+          deps.logger.warn('rolling back a restart offer reservation failed', {
+            scope: 'restart-offer-rollback',
+            operationId
+          })
         })
       }
       throw error
@@ -280,7 +289,9 @@ export function createStructuredAgentSessionRestartResume(
       remainingCandidates = await list()
       remainingFailures = await failures.list()
     } catch {
-      console.warn('[structured-agent-session] restart offer refresh failed after action')
+      deps.logger.warn('refreshing restart offers after an action failed', {
+        scope: 'restart-offer-refresh'
+      })
     }
     return {
       resumed,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-resume-wiring.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-resume-wiring.ts
index bb9eb500d1d..2284367c14b 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-resume-wiring.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-resume-wiring.ts
@@ -1,8 +1,7 @@
 // Binds the restart-resume surface to the host's own capabilities.
 //
 // Its own file because the bindings carry real decisions — which caller key the continuation sends
-// under, that the verdict comes from the settlement waiter rather than the send result, and where a
-// failed journal note is reported — and those belong next to the collaborator that consumes them
+// under, that the verdict comes from the settlement waiter rather than the send result, — and those belong next to the collaborator that consumes them
 // rather than buried in the host constructor.
 
 import type { AgentJournalMessageItem } from '../../../shared/agent-session-journal-types'
@@ -30,7 +29,6 @@ export type StructuredAgentSessionRestartResumeSurfaces = {
     sessionId: string,
     clientMessageId: string
   ) => Promise<{ value: AgentSessionSendResult } | undefined>
-  onNoteFailed: (sessionId: string, error: unknown) => void
   /** The session's child records, the host's one read of them. */
   readChildWork: (sessionId: string) => readonly AgentChildWorkView[] | undefined
   now: () => number
@@ -79,8 +77,6 @@ export function structuredAgentSessionRestartResumeSurfaces(
         until: 'handed-over',
         budgetMs: MAX_TIMER_DELAY_MS
       }),
-    onNoteFailed: () =>
-      console.warn('[structured-agent-session] restart continuation attribution failed'),
     now
   }
 }
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-status-publication.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-status-publication.test.ts
index 35425a70afe..6cde8d87b84 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-status-publication.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-status-publication.test.ts
@@ -27,6 +27,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 
@@ -57,6 +58,7 @@ function adapter(): StructuredAgentSessionAdapter {
 
 function createHost(store: AgentSessionRecordStore): StructuredAgentSessionHost {
   const host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: adapter(),
     journalDatabase: openTestJournalHostDatabase(root),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-teardown.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-teardown.test.ts
index d611bdb1589..3d920db766a 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-restart-teardown.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-restart-teardown.test.ts
@@ -16,12 +16,13 @@ import {
   HOST_TEST_SESSION as SESSION,
   HOST_TEST_THREAD as THREAD
 } from './structured-agent-session-host-test-data'
+import { inspect } from 'node:util'
 
 it.each(['beginTeardown', 'captureBeforeStop', 'recordMarkers'] as const)(
   'keeps private %s failures out of logs while completing teardown',
   async (method) => {
     await attach()
-    const { host, store } = hostTestState()
+    const { host, store, log } = hostTestState()
     const failure = new Error('private recovery payload at /private/account/session.json')
     const warning = vi.spyOn(console, 'warn').mockImplementation(() => {})
     const operation = vi.spyOn(host.restartResume, method).mockImplementation(() => {
@@ -30,14 +31,27 @@ it.each(['beginTeardown', 'captureBeforeStop', 'recordMarkers'] as const)(
     try {
       await expect(host.flushAllStreamedEvents()).resolves.toBeUndefined()
       expect(operation).toHaveBeenCalledOnce()
-      expect(warning).toHaveBeenCalledExactlyOnceWith(
+      expect(warning).toHaveBeenCalledOnce()
+      expect(warning.mock.calls[0]?.[0]).toBe(
         {
-          beginTeardown: '[structured-agent-session] capturing recovery witnesses failed',
-          captureBeforeStop: '[structured-agent-session] capturing recovery witness failed',
-          recordMarkers: '[structured-agent-session] recording recovery capsule failed'
+          beginTeardown:
+            '[agent-session] teardown-recovery-witnesses: capturing recovery witnesses for teardown failed',
+          captureBeforeStop:
+            '[agent-session] recovery-witness: capturing a recovery witness before a stop failed',
+          recordMarkers:
+            '[agent-session] teardown-recovery-capsule: recording the recovery capsule at teardown failed'
         }[method]
       )
-      expect(warning.mock.calls.flat().map(String).join(' ')).not.toContain(failure.message)
+      expect(inspect(warning.mock.calls, { depth: 8 })).not.toContain(failure.message)
+      // Every level and every field the logger received, not only what its console mirror printed.
+      expect(log.scopes()).toContain(
+        {
+          beginTeardown: 'teardown-recovery-witnesses',
+          captureBeforeStop: 'recovery-witness',
+          recordMarkers: 'teardown-recovery-capsule'
+        }[method]
+      )
+      expect(inspect(log.entries, { depth: 8 })).not.toContain('/private/account')
       expect(store.getRecord(SESSION)?.lease.claimStatus).toBe('released')
       await expect(host.journalSnapshot(SESSION)).rejects.toThrow('agent_session_ownership_unknown')
     } finally {
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-restore-without-import.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-restore-without-import.test.ts
index 2ea475cf3ba..51ab878e2c8 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-restore-without-import.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-restore-without-import.test.ts
@@ -38,6 +38,8 @@ import { createStructuredAgentSessionConversationLifetime } from './structured-a
 import type { StructuredAgentSessionLifetimeContext } from './structured-agent-session-host-lifetime'
 import { createStructuredAgentSessionRestartOfferWithdrawal } from './structured-agent-session-restart-offer-withdrawal'
 import { restoreStructuredAgentSessionsOnRestart } from './structured-agent-session-restart-restore'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
+import { recordingStructuredAgentSessionLogger } from './structured-agent-session-logger-test-support'
 
 const { readOnlyOpens, openReadOnly } = vi.hoisted(() => ({
   readOnlyOpens: new Array<string>(),
@@ -216,7 +218,7 @@ type LifetimeHost = Parameters<typeof createStructuredAgentSessionConversationLi
 function conversations(): StructuredAgentSessionConversations {
   return new StructuredAgentSessionConversations({
     deliver: () => undefined,
-    onDeliveryError: () => undefined,
+    logger: recordingStructuredAgentSessionLogger().logger,
     now: () => clock
   })
 }
@@ -228,7 +230,13 @@ async function restore(sessionIds: readonly string[]) {
     getRecord: (sessionId: string) => recordFor(sessionId),
     listRecords: () => sessionIds.map(recordFor)
   } as unknown as AgentSessionRecordStore
-  const deps = { store, adapter: {}, journalDatabase: openTestJournalHostDatabase(root) }
+  const log = recordingStructuredAgentSessionLogger()
+  const deps = {
+    store,
+    adapter: {},
+    journalDatabase: openTestJournalHostDatabase(root),
+    logger: log.logger
+  }
   await restoreStructuredAgentSessionsOnRestart({
     openDeps: deps,
     records: sessionIds.map(recordFor),
@@ -254,7 +262,7 @@ async function restore(sessionIds: readonly string[]) {
       readChildWork: () => undefined
     })
   const lifetime = lifetimeOver(sessions, async (sessionId) => sessions.get(sessionId) ?? null)
-  return { sessions, lifetime, lifetimeOver }
+  return { sessions, lifetime, lifetimeOver, log }
 }
 
 function texts(items: readonly { body: unknown }[]): string {
@@ -377,6 +385,7 @@ describe('startup restore of chats still in their per-chat files', () => {
 
     const { sessions } = await restore(['chat-a'])
     const withdrawal = createStructuredAgentSessionRestartOfferWithdrawal({
+      logger: createStructuredAgentSessionLogger(),
       sessions,
       now: () => clock,
       enqueue: (operation) => operation()
@@ -426,12 +435,11 @@ describe('startup restore of chats still in their per-chat files', () => {
     'refuses a read of the chat restore %s when its copy meets damage, never with the storage text',
     async (reach) => {
       await seedLegacyChat('chat-a')
-      const { sessions, lifetime, lifetimeOver } = await restore(['chat-a'])
+      const { sessions, lifetime, lifetimeOver, log } = await restore(['chat-a'])
       const restored = sessions.get('chat-a')!
       await rm(legacyDirFor('chat-a'), { recursive: true, force: true })
       await mkdir(legacyDirFor('chat-a'), { recursive: true })
       await writeFile(legacyFile('chat-a'), 'not a database, and never was one')
-      vi.spyOn(console, 'warn').mockImplementation(() => undefined)
       const reader =
         reach === 'listed' ? lifetime : lifetimeOver(conversations(), async () => restored)
 
@@ -442,6 +450,12 @@ describe('startup restore of chats still in their per-chat files', () => {
         message: 'agent_session_journal_unreadable',
         refusal: { details: { reason: 'journalCorrupt' } }
       })
+      // The storage text the reader never sees goes to the host's log.
+      expect(log.entries.filter((entry) => entry.fields.scope === 'open-for-read')).toEqual([
+        expect.objectContaining({
+          fields: { scope: 'open-for-read', sessionId: 'chat-a', error: expect.any(Error) }
+        })
+      ])
     }
   )
 
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-reveal.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-reveal.ts
index 262c9e18d3c..3046aa971f6 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-reveal.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-reveal.ts
@@ -72,7 +72,7 @@ export function createStructuredAgentSessionHostRestore(
   restoreReadableSessions: (sessionIds?: readonly string[]) => Promise<void>
 } {
   const { reconcileLeases, resolveRecovery, ...rest } = wiring
-  const failures = reportEachFailureOnce(deps.onLeaseReconcileFailure)
+  const failures = reportEachFailureOnce(deps.logger)
   const reconcile = createReaderReconcile(reconcileLeases, failures)
   const restorer = new StructuredAgentSessionReadableRestorer({
     openDeps: deps,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-rewind-at-rest.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-rewind-at-rest.test.ts
index dd878ebe0d7..c7240eccd83 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-rewind-at-rest.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-rewind-at-rest.test.ts
@@ -26,6 +26,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const caller = { callerKey: 'desktop' }
 const KEPT = { provider: 'codex' as const, threadId: THREAD, turnId: 'kept', ordinal: 0 }
@@ -78,6 +79,7 @@ function adapter(): StructuredAgentSessionAdapter {
 
 function openHost(): StructuredAgentSessionHost {
   return new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: adapter(),
     journalDatabase: openTestJournalHostDatabase(directory),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-rewind.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-rewind.test.ts
index 35e7d5af2e2..6cc37ccb724 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-rewind.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-rewind.test.ts
@@ -29,6 +29,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const caller = { callerKey: 'desktop' }
 let directory: string
@@ -92,6 +93,7 @@ beforeEach(async () => {
     closeSession: async () => true
   }
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter,
     journalDatabase: openTestJournalHostDatabase(directory),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-rewind.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-rewind.ts
index 6358cdfe0f0..f2a1c088e26 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-rewind.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-rewind.ts
@@ -36,6 +36,7 @@ export async function rewindStructuredAgentSession(
     const result = await admitAndRunAgentSessionMutation<AgentSessionRewindResult>({
       store,
       adapter: context.deps.adapter,
+      logger: context.deps.logger,
       callerKey: caller.callerKey,
       envelope: params.envelope,
       // Only the provider can do this, so an agent at rest is started first.
@@ -212,7 +213,7 @@ export async function rewindStructuredAgentSession(
           })
           const journal = context.sessions.get(sessionId)!.journal
           await attachContext.runtimeState.flushEventSink(sessionId)
-          await recoverStructuredRewind(store, sessionId, journal, fence)
+          await recoverStructuredRewind(context.deps, sessionId, journal, fence)
           context.publish(sessionId, journal)
           return { ok: true, value: { itemId: params.itemId, epoch: journal.cursor().epoch } }
         }
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-send-block.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-send-block.test.ts
index 61696b573c0..bcfeadb6727 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-send-block.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-send-block.test.ts
@@ -5,6 +5,7 @@ import {
   openConversationForWrite,
   structuredAgentSessionSendBlock
 } from './structured-agent-session-send-preparation'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 function withCommand(command: AgentSessionConversationCommandRecord) {
   return { ...agentSessionRecordFixture(), conversationCommand: command }
@@ -76,9 +77,13 @@ describe('a write whose conversation the host could not open', () => {
 
   function refusedBy(error: unknown) {
     vi.spyOn(console, 'warn').mockImplementation(() => {})
-    return openConversationForWrite(async () => {
-      throw error
-    }, ENVELOPE)
+    return openConversationForWrite(
+      async () => {
+        throw error
+      },
+      ENVELOPE,
+      createStructuredAgentSessionLogger()
+    )
   }
 
   it('says a corrupt history is final, in words and not the error', async () => {
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-send-idempotency.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-send-idempotency.test.ts
index 1925c13378e..48ceef370e7 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-send-idempotency.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-send-idempotency.test.ts
@@ -9,6 +9,8 @@ import { createTrackedJournalOpener } from '../agent-session-journal/journal-hos
 import type { AgentSessionJournal } from '../agent-session-journal/journal-store'
 import type { StructuredAgentSessionAdapter } from './structured-agent-session-adapter'
 import { performSend, type AgentSessionTurnContext } from './structured-agent-session-turns'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
+import { recordingStructuredAgentSessionLogger } from './structured-agent-session-logger-test-support'
 
 const journals = createTrackedJournalOpener()
 
@@ -56,6 +58,7 @@ describe('structured send idempotency', () => {
 
     const result = await performSend(
       {
+        logger: recordingStructuredAgentSessionLogger().logger,
         sessionId: 'session-1',
         journal,
         fence: 2,
@@ -97,6 +100,7 @@ describe('structured send idempotency', () => {
       }
     }))
     const context: AgentSessionTurnContext = {
+      logger: createStructuredAgentSessionLogger(),
       sessionId: 'session-1',
       journal,
       fence: 1,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-send-open-stale-turn.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-send-open-stale-turn.test.ts
index c85c628d917..c30c33d1f43 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-send-open-stale-turn.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-send-open-stale-turn.test.ts
@@ -25,6 +25,7 @@ import {
   hostTestMessage
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 /** Delivery runs on its own serialized steps; under a loaded runner they take more than a second. */
 function eventually(assertion: () => unknown): Promise<unknown> {
@@ -70,6 +71,7 @@ async function relaunchAfterCrashMidTurn(
     throw new Error('claude: command not found')
   })
   const host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: { ...adapter(), acquire },
     journalDatabase: openTestJournalHostDatabase(relaunched),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-send-preparation.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-send-preparation.test.ts
index 86873faf6b0..cf746e29b74 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-send-preparation.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-send-preparation.test.ts
@@ -71,6 +71,10 @@ beforeEach(async () => {
   }))
   store = await openTestAgentSessionRecordStore(root)
   host = new StructuredAgentSessionHost({
+    logger: {
+      warn: (_message, fields) => hostErrors.push(fields.error),
+      error: (_message, fields) => hostErrors.push(fields.error)
+    },
     store,
     adapter: {
       acquire,
@@ -84,8 +88,7 @@ beforeEach(async () => {
     journalDatabase: openTestJournalHostDatabase(root),
     claimKeyId: 'key-1',
     mintSpawnToken: () => `spawn-${acquire.mock.calls.length}`,
-    now: () => NOW,
-    onEventSinkError: ({ error }) => hostErrors.push(error)
+    now: () => NOW
   })
   expect(await host.attach(CALLER, hostTestAttachParams(null))).toMatchObject({ ok: true })
 })
@@ -407,8 +410,6 @@ describe('a send with no live owner', () => {
     acquire.mockRejectedValue(
       new CodexAppServerRequestError('thread/resume', -32600, `thread/resume failed: ${said}`, said)
     )
-    const warn = vi.spyOn(console, 'warn').mockImplementation(() => undefined)
-
     const id = await accept(sendParams('after the thread went away'))
 
     // The sentence names no cause and quotes nothing; Codex's words ride in the fact for Details.
@@ -426,11 +427,11 @@ describe('a send with no live owner', () => {
       "Codex couldn't restart. Send your message to try again."
     ])
     // Orca's own text is logged once where the start failed.
-    expect(warn).toHaveBeenCalledWith(
-      '[agent-session] provider start failed:',
-      expect.objectContaining({ message: `thread/resume failed: ${said}` })
-    )
-    warn.mockRestore()
+    expect(
+      hostErrors.filter(
+        (error) => error instanceof Error && error.message === `thread/resume failed: ${said}`
+      )
+    ).toHaveLength(1)
   })
 
   it('restarts again for a Retry under a new id, and replays a resend of the same id', async () => {
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-send-preparation.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-send-preparation.ts
index be29089991b..4b2011a02ee 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-send-preparation.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-send-preparation.ts
@@ -24,6 +24,7 @@ import {
 } from './structured-agent-session-mutation-admission'
 import { rewindRefusal } from './structured-rewind-refusal'
 import type { StructuredAgentSessionMutationContext } from './structured-agent-session-host-mutations'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 /** Why the record refuses any send right now, whoever owns it; null when a send may run. */
 export function structuredAgentSessionSendBlock(
@@ -56,7 +57,8 @@ export function structuredAgentSessionSendBlock(
 /** The conversation a send or a Stop writes to, opened when this host holds it closed. */
 export async function openConversationForWrite(
   openConversation: (sessionId: string) => Promise<StructuredAgentSessionHostSession | null>,
-  envelope: AgentSessionMutationEnvelope
+  envelope: AgentSessionMutationEnvelope,
+  logger: StructuredAgentSessionLogger
 ): Promise<AgentSessionMutationSessionPreparation> {
   try {
     if (await openConversation(envelope.sessionId)) {
@@ -64,26 +66,34 @@ export async function openConversationForWrite(
     }
     return { ok: false, refusal: AGENT_SESSION_NOT_ATTACHED }
   } catch (error) {
-    console.warn('[agent-session] opening the conversation for a write failed:', error)
+    logger.warn('opening the conversation for a write failed', {
+      scope: 'open-for-write',
+      sessionId: envelope.sessionId,
+      error
+    })
     return { ok: false, refusal: journalOpenRefusal(error) }
   }
 }
 
 /** The conversation a write lands in, opened when this host holds it closed. */
 export function openForWrite(
-  context: Pick<StructuredAgentSessionMutationContext, 'openConversation'>,
+  context: Pick<StructuredAgentSessionMutationContext, 'openConversation' | 'deps'>,
   envelope: AgentSessionMutationEnvelope
 ): () => Promise<AgentSessionMutationSessionPreparation> {
-  return () => openConversationForWrite(context.openConversation, envelope)
+  return () => openConversationForWrite(context.openConversation, envelope, context.deps.logger)
 }
 
 /** For an operation only the provider can perform: the conversation, then its agent. */
 export function openWithAgent(
-  context: Pick<StructuredAgentSessionMutationContext, 'openConversation' | 'ensureAgent'>,
+  context: Pick<StructuredAgentSessionMutationContext, 'openConversation' | 'ensureAgent' | 'deps'>,
   envelope: AgentSessionMutationEnvelope
 ): () => Promise<AgentSessionMutationSessionPreparation> {
   return async () => {
-    const opened = await openConversationForWrite(context.openConversation, envelope)
+    const opened = await openConversationForWrite(
+      context.openConversation,
+      envelope,
+      context.deps.logger
+    )
     return opened.ok ? context.ensureAgent(envelope.sessionId) : opened
   }
 }
@@ -95,7 +105,11 @@ export function sendPreparation(
   envelope: AgentSessionMutationEnvelope
 ): () => Promise<AgentSessionMutationSessionPreparation> {
   return async () => {
-    const opened = await openConversationForWrite(context.openConversation, envelope)
+    const opened = await openConversationForWrite(
+      context.openConversation,
+      envelope,
+      context.deps.logger
+    )
     const phase = context.deps.store.getRecord(envelope.sessionId)?.rewind?.phase
     return opened.ok && (phase === 'prepared' || phase === 'provider-succeeded')
       ? context.ensureAgent(envelope.sessionId)
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-send-restarts-failed-start.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-send-restarts-failed-start.test.ts
index 21e50e4dca6..8c5e609b971 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-send-restarts-failed-start.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-send-restarts-failed-start.test.ts
@@ -29,6 +29,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 
@@ -146,6 +147,7 @@ beforeEach(async () => {
   dispatch = vi.fn(async () => ({ state: 'admitted' as const }))
   store = await openTestAgentSessionRecordStore(root)
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: {
       acquire,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-settled-attach-retry.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-settled-attach-retry.test.ts
index 17bb4b0ee1f..f14393df874 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-settled-attach-retry.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-settled-attach-retry.test.ts
@@ -26,6 +26,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 
@@ -107,6 +108,7 @@ beforeEach(async () => {
   dispatch = vi.fn(async () => accepted())
   store = await openTestAgentSessionRecordStore(root)
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: adapter(),
     journalDatabase: openTestJournalHostDatabase(root),
@@ -134,6 +136,7 @@ describe('settled attach retry', () => {
       .mockRejectedValueOnce(new Error('journal path unavailable'))
       .mockResolvedValue(null)
     host = new StructuredAgentSessionHost({
+      logger: createStructuredAgentSessionLogger(),
       store,
       adapter: { ...adapter(), historyFilePath },
       journalDatabase: openTestJournalHostDatabase(root),
@@ -191,6 +194,7 @@ describe('settled attach retry', () => {
     })
     const mintSpawnToken = vi.fn(() => 'spawn-safe')
     host = new StructuredAgentSessionHost({
+      logger: createStructuredAgentSessionLogger(),
       store,
       adapter: adapter(),
       journalDatabase: openTestJournalHostDatabase(root),
@@ -235,6 +239,7 @@ describe('settled attach retry', () => {
     let token = 0
     const mintSpawnToken = vi.fn(() => `spawn-${++token}`)
     host = new StructuredAgentSessionHost({
+      logger: createStructuredAgentSessionLogger(),
       store,
       adapter: adapter(),
       journalDatabase: openTestJournalHostDatabase(root),
@@ -265,6 +270,7 @@ describe('settled attach retry', () => {
     await host.flushAllStreamedEvents()
     store = await openTestAgentSessionRecordStore(root)
     host = new StructuredAgentSessionHost({
+      logger: createStructuredAgentSessionLogger(),
       store,
       adapter: adapter(),
       journalDatabase: openTestJournalHostDatabase(root),
@@ -322,6 +328,7 @@ describe('settled attach retry', () => {
     await host.flushAllStreamedEvents()
     store = await openTestAgentSessionRecordStore(root)
     host = new StructuredAgentSessionHost({
+      logger: createStructuredAgentSessionLogger(),
       store,
       adapter: adapter(),
       journalDatabase: openTestJournalHostDatabase(root),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-start-failure-writer.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-start-failure-writer.test.ts
index e5527d1a5af..79227670238 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-start-failure-writer.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-start-failure-writer.test.ts
@@ -27,6 +27,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 const EXIT_REASON = 'Claude Code is not signed in. Sign in with the Claude CLI'
@@ -120,6 +121,7 @@ beforeEach(async () => {
   )
   store = await openTestAgentSessionRecordStore(root)
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: {
       acquire: vi.fn(async ({ fence, spawnToken }) => ({
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-startup-failure-exit.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-startup-failure-exit.test.ts
index 3c4096be138..8235d0d6705 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-startup-failure-exit.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-startup-failure-exit.test.ts
@@ -10,6 +10,7 @@ import {
   type StructuredAgentSessionUnexpectedExitContext,
   type StructuredAgentSessionUnexpectedExitSession
 } from './structured-agent-session-unexpected-exit'
+import { recordingStructuredAgentSessionLogger } from './structured-agent-session-logger-test-support'
 
 const SESSION = 'session-1'
 const GENERATION = 'generation-1'
@@ -47,6 +48,7 @@ function contextFor(session: StructuredAgentSessionUnexpectedExitSession) {
     })
   )
   const context: StructuredAgentSessionUnexpectedExitContext<typeof session> = {
+    logger: recordingStructuredAgentSessionLogger().logger,
     store: {
       getRecord: () => record,
       transitionHandoff: async (
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-startup-reconcile-failure.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-startup-reconcile-failure.test.ts
index d4f8bce0033..b71022b92c7 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-startup-reconcile-failure.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-startup-reconcile-failure.test.ts
@@ -81,8 +81,17 @@ async function relaunch(
     await seedTestAgentSessionStoreFromNewerBuild(relaunched)
   }
   const store = await openTestAgentSessionRecordStore(relaunched)
-  const onLeaseReconcileFailure = vi.fn()
+  // The lease-reconcile entries the host logs, by the failure each reports.
+  const leaseReconcileLogged = vi.fn()
   const host = new StructuredAgentSessionHost({
+    logger: {
+      warn: (_message, fields) => {
+        if (fields.scope === 'lease-reconcile') {
+          leaseReconcileLogged(fields.error)
+        }
+      },
+      error: () => undefined
+    },
     store,
     adapter: adapter(),
     journalDatabase: openTestJournalHostDatabase(relaunched),
@@ -92,30 +101,29 @@ async function relaunch(
     stopOwnerProcess: () => {
       throw new Error('an owner not proven alive must not be stopped')
     },
-    now: () => NOW,
-    onLeaseReconcileFailure
+    now: () => NOW
   })
   replaceHostTestState({ store, host })
-  return { host, store, stateDirectory: relaunched, onLeaseReconcileFailure }
+  return { host, store, stateDirectory: relaunched, leaseReconcileLogged }
 }
 
 it('reports a startup reconcile whose store write fails, and does not reject', async () => {
-  const { host, store, onLeaseReconcileFailure } = await relaunch()
+  const { host, store, leaseReconcileLogged } = await relaunch()
 
   writes.failing = true
   await expect(host.reconcileRestartLeases()).resolves.toBeUndefined()
 
-  expect(onLeaseReconcileFailure).toHaveBeenCalledOnce()
-  expect(onLeaseReconcileFailure).toHaveBeenCalledWith(IO_ERROR)
+  expect(leaseReconcileLogged).toHaveBeenCalledOnce()
+  expect(leaseReconcileLogged).toHaveBeenCalledWith(IO_ERROR)
   // Nothing was adjudicated, so the lease still grants no writer.
   expect(store.getRecord(SESSION)?.lease.unreconciled).toBe(true)
 })
 
 it('reconciles the chat on its next send once the store can be written again', async () => {
-  const { host, store, onLeaseReconcileFailure } = await relaunch()
+  const { host, store, leaseReconcileLogged } = await relaunch()
   writes.failing = true
   await host.reconcileRestartLeases()
-  expect(onLeaseReconcileFailure).toHaveBeenCalledOnce()
+  expect(leaseReconcileLogged).toHaveBeenCalledOnce()
   writes.failing = false
 
   const body = hostTestMessage('sent after a startup reconcile failed')
@@ -128,13 +136,13 @@ it('reconciles the chat on its next send once the store can be written again', a
     timeout: 10_000
   })
   expect(store.getRecord(SESSION)?.lease.unreconciled).toBe(false)
-  expect(onLeaseReconcileFailure).toHaveBeenCalledOnce()
+  expect(leaseReconcileLogged).toHaveBeenCalledOnce()
   // Before the relaunched directory is removed, so the child's wind-down can write its lease.
   await host.flushAllStreamedEvents()
 })
 
 it('adjudicates records a newer Orca wrote in memory only, and writes nothing', async () => {
-  const { host, store, stateDirectory, onLeaseReconcileFailure } = await relaunch(true)
+  const { host, store, stateDirectory, leaseReconcileLogged } = await relaunch(true)
   expect(store.readOnly).toBe(true)
   const path = journalDatabasePath(stateDirectory)
   const bytes = await readFile(path)
@@ -142,7 +150,7 @@ it('adjudicates records a newer Orca wrote in memory only, and writes nothing',
 
   await expect(host.reconcileRestartLeases()).resolves.toBeUndefined()
 
-  expect(onLeaseReconcileFailure).not.toHaveBeenCalled()
+  expect(leaseReconcileLogged).not.toHaveBeenCalled()
   expect(store.getRecord(SESSION)?.lease).toMatchObject({
     unreconciled: false,
     claimStatus: 'released'
@@ -152,7 +160,7 @@ it('adjudicates records a newer Orca wrote in memory only, and writes nothing',
 })
 
 it('restores a chat for reading while the reconcile keeps failing, and reports it once', async () => {
-  const { host, store, onLeaseReconcileFailure } = await relaunch()
+  const { host, store, leaseReconcileLogged } = await relaunch()
   writes.failing = true
   await host.reconcileRestartLeases()
 
@@ -160,8 +168,8 @@ it('restores a chat for reading while the reconcile keeps failing, and reports i
 
   expect(host.hasSession(SESSION)).toBe(true)
   expect(store.getRecord(SESSION)?.lease.unreconciled).toBe(true)
-  expect(onLeaseReconcileFailure).toHaveBeenCalledOnce()
-  expect(onLeaseReconcileFailure).toHaveBeenCalledWith(IO_ERROR)
+  expect(leaseReconcileLogged).toHaveBeenCalledOnce()
+  expect(leaseReconcileLogged).toHaveBeenCalledWith(IO_ERROR)
 })
 
 it('refuses a send over records a newer Orca wrote with the update words', async () => {
@@ -182,20 +190,20 @@ it('refuses a send over records a newer Orca wrote with the update words', async
 })
 
 it('restores a chat for reading from records a newer Orca wrote', async () => {
-  const { host, stateDirectory, onLeaseReconcileFailure } = await relaunch(true)
+  const { host, stateDirectory, leaseReconcileLogged } = await relaunch(true)
   const path = journalDatabasePath(stateDirectory)
   const bytes = await readFile(path)
 
   await expect(host.restoreReadableSessions([SESSION])).resolves.toBeUndefined()
 
   expect(host.hasSession(SESSION)).toBe(true)
-  expect(onLeaseReconcileFailure).not.toHaveBeenCalled()
+  expect(leaseReconcileLogged).not.toHaveBeenCalled()
   expect(await readFile(path)).toEqual(bytes)
 })
 
 // A chat whose owner could not be proven gone is left recovering; the next attach or send retries it.
 it('restores a chat for reading when resolving its recovery cannot write the store', async () => {
-  const { host, store, onLeaseReconcileFailure } = await relaunch(false, async () => ({
+  const { host, store, leaseReconcileLogged } = await relaunch(false, async () => ({
     outcome: 'indeterminate',
     reason: 'probe'
   }))
@@ -207,17 +215,17 @@ it('restores a chat for reading when resolving its recovery cannot write the sto
 
   expect(host.hasSession(SESSION)).toBe(true)
   expect(store.getRecord(SESSION)?.lease.handoffStage).toBe('recovering')
-  expect(onLeaseReconcileFailure).toHaveBeenCalledOnce()
-  expect(onLeaseReconcileFailure).toHaveBeenCalledWith(IO_ERROR)
+  expect(leaseReconcileLogged).toHaveBeenCalledOnce()
+  expect(leaseReconcileLogged).toHaveBeenCalledWith(IO_ERROR)
 })
 
 it.each([
   ['startup reconcile', (host: StructuredAgentSessionHost) => host.reconcileRestartLeases()],
   ['read restore', (host: StructuredAgentSessionHost) => host.restoreReadableSessions([SESSION])]
-])('keeps the %s resolving when the failure sink throws', async (_step, read) => {
-  const { host, onLeaseReconcileFailure } = await relaunch()
+])('keeps the %s resolving when the logger throws', async (_step, read) => {
+  const { host, leaseReconcileLogged } = await relaunch()
   const sinkError = new Error('error sink failed')
-  onLeaseReconcileFailure.mockImplementation(() => {
+  leaseReconcileLogged.mockImplementation(() => {
     throw sinkError
   })
   const warn = vi.spyOn(console, 'warn').mockImplementation(() => {})
@@ -225,10 +233,10 @@ it.each([
   try {
     await expect(read(host)).resolves.toBeUndefined()
 
-    expect(onLeaseReconcileFailure).toHaveBeenCalledOnce()
+    expect(leaseReconcileLogged).toHaveBeenCalledOnce()
     expect(warn).toHaveBeenCalledWith(
-      expect.stringContaining('reporting a lease bookkeeping failure failed'),
-      expect.objectContaining({ failure: IO_ERROR, sinkError })
+      expect.stringContaining('chat lease bookkeeping for a read failed'),
+      expect.objectContaining({ error: IO_ERROR, loggerError: sinkError })
     )
   } finally {
     warn.mockRestore()
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed-child-work.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed-child-work.test.ts
index 03c490742ce..cfb801c8fd6 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed-child-work.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed-child-work.test.ts
@@ -10,6 +10,7 @@ import {
   type StructuredAgentSessionStatusSink
 } from './structured-agent-session-status-feed'
 import { indexedStatusFeedSession } from './structured-agent-session-status-feed-test-session'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const SESSION = 'status-session'
 const EVIDENCE: AgentChildWorkEvidence[] = [{ type: 'session-ended', observedAt: 5 }]
@@ -38,6 +39,7 @@ async function feedWith(sink: StructuredAgentSessionStatusSink) {
   })
   const session = indexedStatusFeedSession({ journal })
   return new StructuredAgentSessionStatusFeed({
+    logger: createStructuredAgentSessionLogger(),
     sessions: new Map([[SESSION, session]]),
     getRecord: () => null,
     now: () => 1_000,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed-child.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed-child.test.ts
index 545a0ebb460..c6777d8a07a 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed-child.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed-child.test.ts
@@ -6,6 +6,7 @@ import type { AgentSessionStatusEvent } from '../../../shared/agent-session-wire
 import { createTrackedJournalOpener } from '../agent-session-journal/journal-host-database-test-support'
 import { StructuredAgentSessionStatusFeed } from './structured-agent-session-status-feed'
 import { indexedStatusFeedSession } from './structured-agent-session-status-feed-test-session'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const SESSION = 'status-session'
 const journals = createTrackedJournalOpener()
@@ -42,6 +43,7 @@ it('publishes each provider child even when a replacement has the same startup p
   setChild({ phase: 'starting', generation: 'child-1', fence: 1 })
   const events: AgentSessionStatusEvent[] = []
   const feed = new StructuredAgentSessionStatusFeed({
+    logger: createStructuredAgentSessionLogger(),
     sessions,
     getRecord: () => null,
     now: () => 1
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed-children.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed-children.test.ts
index c4e8100c30a..30ddeea9678 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed-children.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed-children.test.ts
@@ -22,6 +22,7 @@ import {
   indexedStatusFeedSession,
   statusFeedChildView as childView
 } from './structured-agent-session-status-feed-test-session'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const SESSION = 'status-session'
 const USER_IDENTITY = {
@@ -75,6 +76,7 @@ async function feedWithChildren(provider: AgentSessionHandleProvider = 'codex')
   }
   let now = 1_000
   const feed = new StructuredAgentSessionStatusFeed({
+    logger: createStructuredAgentSessionLogger(),
     sessions: new Map([[SESSION, indexedStatusFeedSession({ journal, provider })]]),
     getRecord: () => null,
     now: () => (now += 1),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed-clock.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed-clock.test.ts
index c3922852245..09a3442985b 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed-clock.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed-clock.test.ts
@@ -14,6 +14,7 @@ import type { AgentSessionStatusSummary } from '../../../shared/agent-session-wi
 import { createTrackedJournalOpener } from '../agent-session-journal/journal-host-database-test-support'
 import { StructuredAgentSessionStatusFeed } from './structured-agent-session-status-feed'
 import { indexedStatusFeedSession } from './structured-agent-session-status-feed-test-session'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const SESSION = 'clock-session'
 const THREAD = 'thread-1'
@@ -60,6 +61,7 @@ async function openFeed() {
     stateDirectory: join(root, SESSION)
   })
   const feed = new StructuredAgentSessionStatusFeed({
+    logger: createStructuredAgentSessionLogger(),
     sessions: new Map([[SESSION, indexedStatusFeedSession({ journal })]]),
     getRecord: () => null,
     now: () => clock
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed.test.ts
index 8062b740bcb..579be82e0c9 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed.test.ts
@@ -23,6 +23,8 @@ import {
   type StructuredAgentSessionStatusFeedDeps,
   type StructuredAgentSessionStatusSink
 } from './structured-agent-session-status-feed'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
+import { testEventSinkLogging } from './structured-agent-session-logger-test-support'
 
 const SESSION = 'status-session'
 const TURN_IDENTITY = {
@@ -79,6 +81,7 @@ function feedFor(
     statusSink ??
     (readChildWork ? { publish: () => {}, forget: () => {}, readChildWork } : undefined)
   const feed = new StructuredAgentSessionStatusFeed({
+    logger: createStructuredAgentSessionLogger(),
     ...(onStatusChanged ? { onStatusChanged } : {}),
     ...(sink ? { statusSink: () => sink } : {}),
     sessions: {
@@ -546,7 +549,7 @@ describe('StructuredAgentSessionStatusFeed', () => {
       const { feed } = feedFor(new Map([[SESSION, { journal }]]), null, (summary) =>
         seen.push(summary.status)
       )
-      const deferred = createDeferredStructuredAgentSessionEventSink()
+      const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
       if (agent === 'claude') {
         const translator = createClaudeJournalTranslator({ sink: deferred.sink })
         translator.handle({
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed.ts
index 4f717d2c31b..ffb6767a321 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-status-feed.ts
@@ -28,6 +28,10 @@ import {
   type StructuredAgentSessionStatusState
 } from './structured-agent-session-status-journal-projection'
 import { structuredStatusSummariesEqual } from './structured-agent-session-status-summary-equality'
+import {
+  deferredStructuredAgentSessionLogger,
+  type StructuredAgentSessionLogger
+} from './structured-agent-session-logger'
 import {
   StructuredAgentSessionStatusOwnership,
   type StructuredAgentSessionStatusSink
@@ -52,6 +56,8 @@ export type StructuredAgentSessionStatusFeedDeps = {
   sessions: ReadonlyMap<string, StatusFeedSession>
   getRecord: (sessionId: string) => AgentSessionRecord | null
   now: () => number
+  /** Where a failing sink or observer is reported; neither may cost subscribers their event. */
+  logger: StructuredAgentSessionLogger
   /** Every projection change, whether or not anyone is subscribed. `replay` marks a re-projection
    *  of state the host already knew (restore, an arriving subscriber) rather than a journal edge. */
   onStatusChanged?: (summary: AgentSessionStatusSummary, options: { replay: boolean }) => void
@@ -72,6 +78,7 @@ export function createStructuredAgentSessionHostStatusFeed(args: {
   now: () => number
   deps: () => {
     store: { getRecord: (sessionId: string) => AgentSessionRecord | null }
+    logger: StructuredAgentSessionLogger
     onSessionStatusChanged?: StructuredAgentSessionStatusFeedDeps['onStatusChanged']
     statusSink?: StructuredAgentSessionStatusSink
   }
@@ -82,6 +89,7 @@ export function createStructuredAgentSessionHostStatusFeed(args: {
     sessions: args.sessions,
     getRecord: (sessionId) => args.deps().store.getRecord(sessionId),
     now: args.now,
+    logger: deferredStructuredAgentSessionLogger(() => args.deps().logger),
     onStatusChanged: (summary, options) => args.deps().onSessionStatusChanged?.(summary, options),
     // Resolved per call for the same reason the other deps are: the host builds this feed in a
     // field initializer, before its constructor parameters are assigned.
@@ -104,6 +112,10 @@ export class StructuredAgentSessionStatusFeed {
 
   constructor(private readonly deps: StructuredAgentSessionStatusFeedDeps) {}
 
+  private logFailure(scope: string, message: string, sessionId: string, error: unknown): void {
+    this.deps.logger.warn(message, { scope, sessionId, error })
+  }
+
   /** Opens with every session this host has projected, live ones re-read, then only changes. */
   subscribe(subscriber: StructuredAgentSessionStatusSubscriber): () => void {
     // Re-project before registering: a change found here has to reach the subscribers that
@@ -131,7 +143,7 @@ export class StructuredAgentSessionStatusFeed {
     try {
       this.ownership.forget(sessionId)
     } catch (error) {
-      console.warn('[structured-session-status] status sink forget failed', error)
+      this.logFailure('status-sink-forget', 'status sink forget failed', sessionId, error)
     }
     const previous = this.published.get(sessionId)
     if (!previous || (!previous.children && !previous.backgroundTasks)) {
@@ -215,7 +227,7 @@ export class StructuredAgentSessionStatusFeed {
       this.deps.onStatusChanged?.(summary, { replay: options?.replay === true })
     } catch (error) {
       // An observer must never cost the subscribers their status event.
-      console.warn('[structured-session-status] status observer failed', error)
+      this.logFailure('status-observer', 'status observer failed', sessionId, error)
     }
   }
 
@@ -315,7 +327,7 @@ export class StructuredAgentSessionStatusFeed {
     try {
       return this.ownership.readChildWork(sessionId)
     } catch (error) {
-      console.warn('[structured-session-status] child work read failed', error)
+      this.logFailure('child-work-read', 'child work read failed', sessionId, error)
       return undefined
     }
   }
@@ -328,13 +340,13 @@ export class StructuredAgentSessionStatusFeed {
     try {
       this.ownership.publishChildWork(sessionId, evidence, session.params.provider)
     } catch (error) {
-      console.warn('[structured-session-status] child work publish failed', error)
+      this.logFailure('child-work-publish', 'child work publish failed', sessionId, error)
       return false
     }
     try {
       this.deps.onChildWorkChanged?.(sessionId)
     } catch (error) {
-      console.warn('[structured-session-status] child work observer failed', error)
+      this.logFailure('child-work-observer', 'child work observer failed', sessionId, error)
     }
     return true
   }
@@ -347,7 +359,7 @@ export class StructuredAgentSessionStatusFeed {
     try {
       this.ownership.publish(summary, location)
     } catch (error) {
-      console.warn('[structured-session-status] status sink publish failed', error)
+      this.logFailure('status-sink-publish', 'status sink publish failed', summary.sessionId, error)
     }
   }
 
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-status-reentry.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-status-reentry.test.ts
index fff0ae2383b..aea5e93168a 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-status-reentry.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-status-reentry.test.ts
@@ -13,6 +13,7 @@ import {
   StructuredAgentSessionStatusFeed,
   type StructuredAgentSessionStatusSink
 } from './structured-agent-session-status-feed'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const SESSION = 'reenter-session'
 const journals = createTrackedJournalOpener()
@@ -62,6 +63,7 @@ async function createFeed() {
     forget: vi.fn((subject) => server.dropStructuredStatus(subject))
   }
   const feed = new StructuredAgentSessionStatusFeed({
+    logger: createStructuredAgentSessionLogger(),
     sessions,
     getRecord: () => null,
     now: () => 1_000,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-subagent-recency.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-subagent-recency.test.ts
index dafe54e1790..d47efcd4cad 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-subagent-recency.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-subagent-recency.test.ts
@@ -20,6 +20,8 @@ import { createTrackedJournalOpener } from '../agent-session-journal/journal-hos
 import { createDeferredStructuredAgentSessionEventSink } from './structured-agent-session-event-sink'
 import { StructuredAgentSessionStatusFeed } from './structured-agent-session-status-feed'
 import { indexedStatusFeedSession } from './structured-agent-session-status-feed-test-session'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
+import { testEventSinkLogging } from './structured-agent-session-logger-test-support'
 
 const SESSION = 'recency-session'
 const CODEX_THREAD = 'thread-parent'
@@ -60,6 +62,7 @@ async function openSession() {
   // The host's status row and child records, which the feed writes into and reads back.
   const server = new AgentHookServer()
   const feed = new StructuredAgentSessionStatusFeed({
+    logger: createStructuredAgentSessionLogger(),
     sessions: new Map([
       [
         SESSION,
@@ -81,7 +84,7 @@ async function openSession() {
   })
   const events: AgentSessionStatusEvent[] = []
   feed.subscribe({ id: 'list-1', emit: (event) => events.push(event) })
-  const deferred = createDeferredStructuredAgentSessionEventSink()
+  const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
   deferred.bind({ journal, fence: 1, publish: () => feed.publish(SESSION, journal) })
   const drain = async (): Promise<void> => {
     expect(await deferred.drained()).toEqual({ ok: true })
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-subscribers.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-subscribers.test.ts
index cf31d1d47f1..3881e8c429f 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-subscribers.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-subscribers.test.ts
@@ -23,6 +23,7 @@ import {
 import { StructuredAgentSessionStatusFeed } from './structured-agent-session-status-feed'
 import { MAX_RETAINED_SESSION_ACTIVITIES } from './structured-agent-session-activity-retention'
 import { AgentSessionSubscribers } from './structured-agent-session-subscribers'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const SESSION = 'subscriber-session'
 
@@ -227,6 +228,7 @@ describe('AgentSessionSubscribers', () => {
       stateDirectory: join(root, 'unread-journal')
     })
     const statusFeed = new StructuredAgentSessionStatusFeed({
+      logger: createStructuredAgentSessionLogger(),
       sessions: new Map([
         [
           SESSION,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-surface-lifetime.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-surface-lifetime.test.ts
index 871c05a6e33..6ef96b7f98c 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-surface-lifetime.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-surface-lifetime.test.ts
@@ -76,6 +76,10 @@ function openHost(
   probeOwner?: (record: AgentSessionRecord) => Promise<AgentSessionOwnerProbe>
 ): void {
   host = new StructuredAgentSessionHost({
+    logger: {
+      warn: (_message, fields) => hostErrors.push(fields.error),
+      error: (_message, fields) => hostErrors.push(fields.error)
+    },
     store,
     adapter: adapter(),
     journalDatabase: openTestJournalHostDatabase(root),
@@ -83,7 +87,6 @@ function openHost(
     mintSpawnToken: () => `spawn-${acquire.mock.calls.length}`,
     idleSweep: { intervalMs: SWEEP_MS, idleMs: IDLE_MS },
     now: () => clock,
-    onEventSinkError: ({ error }) => hostErrors.push(error),
     statusSink,
     ...(probeOwner ? { probeOwner } : {})
   })
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-thread-goal.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-thread-goal.test.ts
index c9cdaa997b1..7e59f695d6d 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-thread-goal.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-thread-goal.test.ts
@@ -16,6 +16,7 @@ import {
   threadGoalPlan
 } from './structured-agent-session-thread-goal'
 import type { AgentSessionTurnContext } from './structured-agent-session-turns'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const IDENTITY: AgentSessionJournalIdentity = {
   sessionId: 'session-1',
@@ -68,6 +69,7 @@ function context(
   flushStreamedEvents: () => Promise<void> = async () => undefined
 ): AgentSessionTurnContext {
   return {
+    logger: createStructuredAgentSessionLogger(),
     sessionId: 'session-1',
     journal,
     fence: 1,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-turns.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-turns.test.ts
index 3e497c311ba..a09024ffcdd 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-turns.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-turns.test.ts
@@ -8,6 +8,7 @@ import type { AgentChildWorkView } from '../../../shared/agent-status-child-work
 import { createTrackedJournalOpener } from '../agent-session-journal/journal-host-database-test-support'
 import type { StructuredAgentSessionAdapter } from './structured-agent-session-adapter'
 import { performCancel, type AgentSessionTurnContext } from './structured-agent-session-turns'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const IDENTITY: AgentSessionJournalIdentity = {
   sessionId: 'session-1',
@@ -49,6 +50,7 @@ describe('performCancel', () => {
     )
     const cancelTurn = vi.fn(async () => ({ cancelled: true }))
     const ctx: AgentSessionTurnContext = {
+      logger: createStructuredAgentSessionLogger(),
       sessionId: 'session-1',
       journal,
       fence: 1,
@@ -103,6 +105,7 @@ describe('performCancel', () => {
       }
     )
     const ctx: AgentSessionTurnContext = {
+      logger: createStructuredAgentSessionLogger(),
       sessionId: 'session-1',
       journal,
       fence: 1,
@@ -148,6 +151,7 @@ describe('performCancel', () => {
       { fence: 1, turnScope: AGENT_JOURNAL_THREAD_SCOPE }
     )
     const ctx: AgentSessionTurnContext = {
+      logger: createStructuredAgentSessionLogger(),
       sessionId: 'session-1',
       journal,
       fence: 1,
@@ -182,6 +186,7 @@ describe('performCancel', () => {
     const cancelTurn = vi.fn(async () => ({ cancelled: true }))
     const stopBackgroundTasks = vi.fn(async () => ({ cancelled: true }))
     const ctx: AgentSessionTurnContext = {
+      logger: createStructuredAgentSessionLogger(),
       sessionId: 'session-1',
       journal,
       fence: 1,
@@ -220,6 +225,7 @@ describe('performCancel', () => {
     const cancelTurn = vi.fn(async () => ({ cancelled: true }))
     const stopBackgroundTasks = vi.fn(async () => ({ cancelled: true }))
     const ctx: AgentSessionTurnContext = {
+      logger: createStructuredAgentSessionLogger(),
       sessionId: 'session-1',
       journal,
       fence: 1,
@@ -299,6 +305,7 @@ describe('what a conversation Stop reports when the provider stopped nothing', (
       await openTurn()
     }
     const ctx: AgentSessionTurnContext = {
+      logger: createStructuredAgentSessionLogger(),
       sessionId: 'session-1',
       journal,
       fence: 1,
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-turns.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-turns.ts
index 13aa9d72aea..6ee38fa1d62 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-turns.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-turns.ts
@@ -41,6 +41,7 @@ import {
   isJournalWrittenByNewerOrca,
   journalOpenRefusal
 } from '../agent-session-journal/journal-open-failure'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
 export { performSetOption } from './structured-agent-session-turns-options'
 export { performPrompt } from './structured-agent-session-turns-prompt'
 export { performCancel } from './structured-agent-session-turns-cancel'
@@ -50,6 +51,7 @@ export type AgentSessionTurnContext = {
   journal: AgentSessionJournal
   fence: number
   adapter: StructuredAgentSessionAdapter
+  logger: StructuredAgentSessionLogger
   persistedOptions?: Readonly<Record<string, string>>
   persistOptions: (options: Readonly<Record<string, string>>) => Promise<void>
   /** Opaque client identity recorded as the resolver of a prompt. */
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-unexpected-exit.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-unexpected-exit.test.ts
index 2cb38a46634..b2ddb882207 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-unexpected-exit.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-unexpected-exit.test.ts
@@ -13,6 +13,7 @@ import {
   type StructuredAgentSessionUnexpectedExitContext,
   type StructuredAgentSessionUnexpectedExitSession
 } from './structured-agent-session-unexpected-exit'
+import { recordingStructuredAgentSessionLogger } from './structured-agent-session-logger-test-support'
 
 const exitOutcome = (agent: string): string =>
   `${agent} stopped while this response was in progress. You can continue in this conversation.`
@@ -104,7 +105,9 @@ describe('provider-exit settlement', () => {
     } as unknown as StructuredAgentSessionHostSession
 
     await settleUnexpectedStructuredAgentSessionExit(
+      // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: the exit settlement reads only these members of its context; the store double is partial.
       {
+        logger: recordingStructuredAgentSessionLogger().logger,
         store,
         sessions: new Map([[SESSION, session]]),
         flushLifecycle: async () => {
@@ -295,6 +298,7 @@ describe('provider-exit settlement', () => {
 
       const { store } = mutableStore()
       const context: StructuredAgentSessionUnexpectedExitContext<typeof session> = {
+        logger: recordingStructuredAgentSessionLogger().logger,
         store,
         sessions: new Map([[SESSION, session]]),
         flushLifecycle: async () => {
@@ -354,6 +358,7 @@ describe('provider-exit settlement', () => {
 
     const { store } = mutableStore()
     const context: StructuredAgentSessionUnexpectedExitContext<typeof session> = {
+      logger: recordingStructuredAgentSessionLogger().logger,
       store,
       sessions: new Map([[SESSION, session]]),
       flushLifecycle: async () => ({ ok: true }),
@@ -406,7 +411,7 @@ describe('provider-exit settlement', () => {
         })
       }
     }
-    const release = vi.fn()
+    const log = recordingStructuredAgentSessionLogger()
     const publishFence = vi.fn()
     const event = {
       type: 'ended' as const,
@@ -424,12 +429,12 @@ describe('provider-exit settlement', () => {
       publishFence,
       serialize: async (_sessionId, task) => task(),
       now: () => 1,
-      onBarrierError: release
+      logger: log.logger
     }
     await settleUnexpectedStructuredAgentSessionExit(context, event)
 
     expect(session.child).toBeNull()
     expect(publishFence).toHaveBeenCalledTimes(1)
-    expect(release).toHaveBeenCalledTimes(2)
+    expect(log.scopes()).toEqual(['exit-lifecycle-barrier', 'exit-settlement'])
   })
 })
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-unexpected-exit.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-unexpected-exit.ts
index 3f758f81607..419f7005c40 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-unexpected-exit.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-unexpected-exit.ts
@@ -17,6 +17,7 @@ import {
   unfinishedStructuredAgentSessionWorkWasInterrupted
 } from './structured-agent-session-dead-generation-settlement'
 import type { StructuredAgentSessionTurnVerdict } from './structured-agent-session-stale-turn-verdict'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 type UnexpectedExitLifecycleEvent = StructuredAgentSessionEndedEvent & {
   cause: 'unexpected-exit'
@@ -37,7 +38,7 @@ export type StructuredAgentSessionUnexpectedExitContext<
   publishStatus?: (sessionId: string) => void
   serialize: <T>(sessionId: string, task: () => Promise<T>) => Promise<T>
   now: () => number
-  onBarrierError?: (sessionId: string, error: unknown) => void
+  logger: StructuredAgentSessionLogger
 }
 
 export async function settleUnexpectedStructuredAgentSessionExit<
@@ -93,10 +94,10 @@ export async function settleUnexpectedStructuredAgentSessionExit<
       try {
         const barrier = await context.flushLifecycle(unexpectedEvent.sessionId)
         if (!barrier.ok) {
-          context.onBarrierError?.(unexpectedEvent.sessionId, barrier.error)
+          logExitFailure(context, unexpectedEvent, 'exit-lifecycle-barrier', barrier.error)
         }
       } catch (error) {
-        context.onBarrierError?.(unexpectedEvent.sessionId, error)
+        logExitFailure(context, unexpectedEvent, 'exit-lifecycle-barrier', error)
       }
       await retryUnexpectedExitSettlement({
         context,
@@ -136,7 +137,7 @@ export async function settleUnexpectedStructuredAgentSessionExit<
           exitReason: unexpectedEvent.reason.slice(0, MAX_UNEXPECTED_EXIT_REASON_CHARS)
         })
       } catch (error) {
-        context.onBarrierError?.(unexpectedEvent.sessionId, error)
+        logExitFailure(context, unexpectedEvent, 'exit-owner-release', error)
       } finally {
         endChild()
         if (released) {
@@ -148,7 +149,7 @@ export async function settleUnexpectedStructuredAgentSessionExit<
 }
 
 async function retryUnexpectedExitSettlement(input: {
-  context: Pick<StructuredAgentSessionUnexpectedExitContext, 'onBarrierError'>
+  context: Pick<StructuredAgentSessionUnexpectedExitContext, 'logger'>
   event: UnexpectedExitLifecycleEvent
   journal: DeadGenerationJournal
   fence: number
@@ -157,8 +158,8 @@ async function retryUnexpectedExitSettlement(input: {
   exitedDuringStartup: boolean
   failureTextContext: AgentSessionFailureWordsContext
   showUnexpectedExitOutcome?: boolean
-}): Promise<boolean> {
-  return settleStructuredAgentSessionDeadGeneration({
+}): Promise<void> {
+  const settled = await settleStructuredAgentSessionDeadGeneration({
     journal: input.journal,
     sessionId: input.event.sessionId,
     fence: input.fence,
@@ -170,8 +171,23 @@ async function retryUnexpectedExitSettlement(input: {
     failureTextContext: input.failureTextContext,
     ...(input.exitedDuringStartup
       ? { exitedDuringStartup: { generation: input.event.acquisitionGeneration } }
-      : {}),
-    onError: input.context.onBarrierError
+      : {})
+  })
+  if (!settled.ok) {
+    logExitFailure(input.context, input.event, 'exit-settlement', settled.error)
+  }
+}
+
+function logExitFailure(
+  context: Pick<StructuredAgentSessionUnexpectedExitContext, 'logger'>,
+  event: UnexpectedExitLifecycleEvent,
+  scope: string,
+  error: unknown
+): void {
+  context.logger.warn('settling a provider exit did not finish', {
+    scope,
+    sessionId: event.sessionId,
+    error
   })
 }
 
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-view-start-after-failed-start.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-view-start-after-failed-start.test.ts
index 3d38c1cb38d..20c5abd595e 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-view-start-after-failed-start.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-view-start-after-failed-start.test.ts
@@ -25,6 +25,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 /** Delivery runs on its own serialized steps; under a loaded runner they take more than a second. */
 function eventually(assertion: () => unknown): Promise<unknown> {
@@ -84,6 +85,7 @@ beforeEach(async () => {
   })
   store = await openTestAgentSessionRecordStore(root)
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: Object.assign(adapter, { supportsCreate: () => true }),
     journalDatabase: openTestJournalHostDatabase(root),
diff --git a/src/main/native-chat/agent-session-wire/structured-agent-session-wedged-profile-migration.test.ts b/src/main/native-chat/agent-session-wire/structured-agent-session-wedged-profile-migration.test.ts
index 2981815c1f1..08532f63c1f 100644
--- a/src/main/native-chat/agent-session-wire/structured-agent-session-wedged-profile-migration.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-agent-session-wedged-profile-migration.test.ts
@@ -50,6 +50,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const CALLER = { callerKey: 'client-1' }
 const DEAD_OWNER: AgentSessionProcessIdentity = {
@@ -121,6 +122,7 @@ async function seedStore(record: PersistedAgentSessionRecord): Promise<void> {
 /** Every recorded owner in these fixtures is long gone; that is the present-time evidence. */
 function openHost(overrides: Partial<StructuredAgentSessionHostDeps> = {}): void {
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: {
       acquire,
diff --git a/src/main/native-chat/agent-session-wire/structured-conversation-command.test.ts b/src/main/native-chat/agent-session-wire/structured-conversation-command.test.ts
index 380869ed21d..8bbec6f5588 100644
--- a/src/main/native-chat/agent-session-wire/structured-conversation-command.test.ts
+++ b/src/main/native-chat/agent-session-wire/structured-conversation-command.test.ts
@@ -23,6 +23,7 @@ import {
   resetHostTestOperationIds
 } from './structured-agent-session-host-test-data'
 import { openTestJournalHostDatabase } from '../agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from './structured-agent-session-logger'
 
 const caller = { callerKey: 'desktop' }
 let directory: string
@@ -64,6 +65,7 @@ let ownerProbe: AgentSessionOwnerProbe = { outcome: 'pid-absent' }
 async function openHost(): Promise<void> {
   store = await openTestAgentSessionRecordStore(generationRoot())
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter,
     journalDatabase: openTestJournalHostDatabase(generationRoot()),
diff --git a/src/main/native-chat/agent-session-wire/structured-conversation-command.ts b/src/main/native-chat/agent-session-wire/structured-conversation-command.ts
index 30a4bfecf51..1df9b08c78f 100644
--- a/src/main/native-chat/agent-session-wire/structured-conversation-command.ts
+++ b/src/main/native-chat/agent-session-wire/structured-conversation-command.ts
@@ -107,6 +107,7 @@ export function runStructuredConversationCommand(
     return admitAndRunAgentSessionMutation({
       store,
       adapter: context.deps.adapter,
+      logger: context.deps.logger,
       callerKey: caller.callerKey,
       envelope,
       // Starts the agent only to settle a rewind in doubt, as a send does; a /clear itself starts nothing.
diff --git a/src/main/native-chat/agent-session-wire/structured-rewind-recovery.ts b/src/main/native-chat/agent-session-wire/structured-rewind-recovery.ts
index b572e51e5f3..a45b821e465 100644
--- a/src/main/native-chat/agent-session-wire/structured-rewind-recovery.ts
+++ b/src/main/native-chat/agent-session-wire/structured-rewind-recovery.ts
@@ -13,6 +13,9 @@ import type { AgentSessionJournal } from '../agent-session-journal/journal-store
 import type { StructuredAgentSessionAdapter } from './structured-agent-session-adapter'
 import { AGENT_SESSION_HISTORY_MAX_PAGE_BYTES } from './agent-session-history-page-bounds'
 import { rewindRefusal } from './structured-rewind-refusal'
+import type { StructuredAgentSessionLogger } from './structured-agent-session-logger'
+
+type RewindRecoveryDeps = { store: AgentSessionRecordStore; logger: StructuredAgentSessionLogger }
 
 export function persistRewindRecord(
   store: AgentSessionRecordStore,
@@ -33,7 +36,7 @@ export function persistRewindRecord(
  * settled refused rather than proven. Bookkeeping only: the chat is already attached either way.
  */
 async function settleUnsupportedClaudeRewind(
-  store: AgentSessionRecordStore,
+  { store, logger }: RewindRecoveryDeps,
   sessionId: string,
   fence: number,
   rewind: AgentSessionRewindRecord
@@ -52,7 +55,8 @@ async function settleUnsupportedClaudeRewind(
       outcome: { status: 'failed', code: refusal.code, rewindReason: 'unsupported' }
     })
   } catch (error) {
-    console.warn('[structured-rewind] pending Claude rewind was not settled:', {
+    logger.warn('a pending Claude rewind was not settled', {
+      scope: 'rewind-unsupported-settlement',
       sessionId,
       operationId: rewind.operationId,
       error
@@ -62,20 +66,21 @@ async function settleUnsupportedClaudeRewind(
 
 /** Recovery observes provider state; it never repeats an ambiguous native mutation. */
 export async function recoverStructuredRewind(
-  store: AgentSessionRecordStore,
+  deps: RewindRecoveryDeps,
   sessionId: string,
   journal: AgentSessionJournal,
   fence: number,
   adapter?: StructuredAgentSessionAdapter,
   now: () => number = Date.now
 ): Promise<void> {
+  const { store } = deps
   let rewind = store.getRecord(sessionId)?.rewind
   if (rewind?.phase !== 'provider-succeeded' && rewind?.phase !== 'prepared') {
     return
   }
   const target = parseAgentJournalItemKey(rewind.providerItemId ?? rewind.itemId)
   if (target?.provider === 'claude') {
-    await settleUnsupportedClaudeRewind(store, sessionId, fence, rewind)
+    await settleUnsupportedClaudeRewind(deps, sessionId, fence, rewind)
     return
   }
   if (target?.provider === 'codex' && !rewind.hydrationVerified) {
diff --git a/src/main/observability/index.ts b/src/main/observability/index.ts
index 74728a2d81b..f620fb9a77d 100644
--- a/src/main/observability/index.ts
+++ b/src/main/observability/index.ts
@@ -139,13 +139,19 @@ let consent: ObservabilityConsent | null = null
 
 /** Create the local file sink, install it as the active tracer sink, and
  *  update module-level `sink`. */
-function installLocalSink(): void {
-  const localSink = createLocalFileSink({ filePath: getTraceFilePath() })
-  sink = localSink
-  setActiveSink(localSink)
+function installLocalSink(filePath: string): void {
+  try {
+    const localSink = createLocalFileSink({ filePath })
+    sink = localSink
+    setActiveSink(localSink)
+  } catch (error) {
+    // Diagnostics are optional: a logs folder that cannot be opened must not stop the app or host.
+    console.warn(`[observability] tracing is off: cannot open ${filePath}`, error)
+  }
 }
 
-export function initObservability(): ObservabilityConsent {
+/** `traceFilePath` names another process's own file; the desktop's is the bundle's default. */
+export function initObservability(options?: { traceFilePath?: string }): ObservabilityConsent {
   const c = resolveObservabilityConsent()
   consent = c
   if (!c.localFileEnabled) {
@@ -153,7 +159,7 @@ export function initObservability(): ObservabilityConsent {
     // tracer's active sink unset, so all spans are no-ops.
     return c
   }
-  installLocalSink()
+  installLocalSink(options?.traceFilePath ?? getTraceFilePath())
   installSecurePathHardeningReporter()
   return c
 }
@@ -183,6 +189,15 @@ function installSecurePathHardeningReporter(): void {
   })
 }
 
+/** Writes buffered lines now, for an exit that runs no shutdown. */
+export function flushObservability(): void {
+  try {
+    sink?.flush()
+  } catch {
+    // Nothing is left to report to.
+  }
+}
+
 export async function shutdownObservability(): Promise<void> {
   setSecurePathHardeningReporter(null)
   // Order matters: tracer first so no new pushes arrive while the local sink
diff --git a/src/main/observability/logs-directory.ts b/src/main/observability/logs-directory.ts
index 20ad104af74..7b244bec43e 100644
--- a/src/main/observability/logs-directory.ts
+++ b/src/main/observability/logs-directory.ts
@@ -35,6 +35,11 @@ export function getTraceFilePath(): string {
   return join(getLogsDirectory(), 'main.trace.ndjson')
 }
 
+/** orcad's own trace file, named for its process as the daemon's log is. */
+export function getOrcadTraceFilePath(): string {
+  return join(getLogsDirectory(), 'orcad.trace.ndjson')
+}
+
 /** NDJSON lifecycle log written by the detached daemon process. Shared here so
  *  the daemon fork (which passes it as `--log-file`) and the bundle collector
  *  (which reads it) agree on one path. */
diff --git a/src/main/orcad/orcad-entry.ts b/src/main/orcad/orcad-entry.ts
index 6c0e9bbad22..854b4dfb723 100644
--- a/src/main/orcad/orcad-entry.ts
+++ b/src/main/orcad/orcad-entry.ts
@@ -30,6 +30,7 @@ import {
 export { parseArgs }
 
 let runOrcadQuitHandlers = (): void => {}
+let closeOrcadObservability = (): void => {}
 
 function createNodeAppEnvironment(): AppEnvironment {
   const quitHandlers: (() => void)[] = []
@@ -109,7 +110,12 @@ export async function startOrcad(options: OrcadOptions = {}): Promise<OrcadHandl
   return startOrcadWithHost(
     resolveUserDataPath(),
     (registerCleanup) => startOrcadRuntime(options, registerCleanup),
-    () => runOrcadQuitHandlers()
+    () => {
+      runOrcadQuitHandlers()
+      // Last, after every quit handler, so the spans they end still reach the file.
+      closeOrcadObservability()
+      closeOrcadObservability = () => {}
+    }
   )
 }
 
@@ -122,6 +128,8 @@ async function startOrcadRuntime(
   const { registerHeadlessPtyRuntime, getLocalPtyProvider, getSshPtyProvider } =
     await import('../ipc/pty')
   const { getAppEnvironment } = await import('../../shared/app-environment')
+  const { installOrcadObservability } = await import('./orcad-observability')
+  closeOrcadObservability = installOrcadObservability()
   const { resolveAdvertisedPairingEndpoint } = await import('../runtime/pairing-endpoint')
   const { ServeReadinessPublisher } = await import('../server/serve-readiness')
   const { createOrcadProfileStateStartup } = await import('./orcad-profile-state-startup')
diff --git a/src/main/orcad/orcad-observability.test.ts b/src/main/orcad/orcad-observability.test.ts
new file mode 100644
index 00000000000..03b49342523
--- /dev/null
+++ b/src/main/orcad/orcad-observability.test.ts
@@ -0,0 +1,122 @@
+import { existsSync, mkdtempSync, readFileSync, rmSync, writeFileSync } from 'node:fs'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+import { setAppEnvironment } from '../../shared/app-environment'
+import { createStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
+import { installOrcadObservability } from './orcad-observability'
+
+const CI_ENV = [
+  'CI',
+  'GITHUB_ACTIONS',
+  'GITLAB_CI',
+  'CIRCLECI',
+  'TRAVIS',
+  'BUILDKITE',
+  'JENKINS_URL',
+  'TEAMCITY_VERSION'
+]
+
+describe('orcad trace file', () => {
+  let dataRoot: string
+
+  beforeEach(() => {
+    dataRoot = mkdtempSync(join(tmpdir(), 'orca-orcad-observability-'))
+    setAppEnvironment({
+      getPath: (name) => {
+        if (name !== 'userData') {
+          throw new Error(`unexpected getPath: ${name}`)
+        }
+        return dataRoot
+      },
+      getAppPath: () => dataRoot,
+      getVersion: () => '0.0.0-test',
+      isPackaged: () => true,
+      onWillQuit: () => {},
+      exit: () => {},
+      getAppMetrics: () => []
+    })
+    // The lane is off in CI and when diagnostics are disabled; this asserts the default host.
+    for (const name of [...CI_ENV, 'ORCA_DIAGNOSTICS_DISABLED']) {
+      vi.stubEnv(name, '')
+    }
+    vi.spyOn(console, 'warn').mockImplementation(() => undefined)
+  })
+
+  afterEach(() => {
+    vi.unstubAllEnvs()
+    vi.restoreAllMocks()
+    rmSync(dataRoot, { recursive: true, force: true })
+  })
+
+  const traceRecords = (): { name: string; attributes: Record<string, unknown> }[] =>
+    readFileSync(join(dataRoot, 'logs', 'orcad.trace.ndjson'), 'utf8')
+      .trim()
+      .split('\n')
+      .map((line) => JSON.parse(line))
+
+  const reportLateSettlement = (): void =>
+    createStructuredAgentSessionLogger().warn('settling a late dispatch failed', {
+      scope: 'late-settlement',
+      sessionId: 'session-1',
+      error: new Error('disk full')
+    })
+
+  it('writes a structured chat failure to its own file under the data root, flushed by close', () => {
+    const close = installOrcadObservability()
+
+    reportLateSettlement()
+    close()
+
+    expect(traceRecords()).toContainEqual(
+      expect.objectContaining({
+        name: 'agentSession.late-settlement',
+        attributes: expect.objectContaining({ sessionId: 'session-1' }),
+        exit: expect.objectContaining({ _tag: 'Failure' })
+      })
+    )
+    expect(existsSync(join(dataRoot, 'logs', 'main.trace.ndjson'))).toBe(false)
+  })
+
+  it('flushes what is buffered when the process exits with no cleanup', () => {
+    const before = new Set(process.listeners('exit'))
+    const close = installOrcadObservability()
+    const onExit = process.listeners('exit').filter((listener) => !before.has(listener))
+    expect(onExit).toHaveLength(1)
+
+    reportLateSettlement()
+    onExit[0]?.call(process, 1)
+
+    expect(traceRecords().map((record) => record.name)).toContain('agentSession.late-settlement')
+    close()
+    expect(process.listeners('exit')).toHaveLength(before.size)
+  })
+
+  it('still starts when the logs folder cannot be opened, with tracing off', () => {
+    // A regular file where the folder belongs fails the open as a read-only mount or EACCES does.
+    writeFileSync(join(dataRoot, 'logs'), 'not a folder')
+    const warn = vi.mocked(console.warn)
+
+    const close = installOrcadObservability()
+    reportLateSettlement()
+    close()
+
+    expect(warn).toHaveBeenCalledWith(
+      expect.stringContaining('[observability] tracing is off'),
+      expect.any(Error)
+    )
+    expect(readFileSync(join(dataRoot, 'logs'), 'utf8')).toBe('not a folder')
+  })
+})
+
+// Booting orcad here would need its whole runtime; the wiring is pinned the way the agent-status
+// store's is, by the entry point's own text.
+it('orcad installs the trace file before its runtime and closes it after every quit handler', () => {
+  const entry = readFileSync(join(import.meta.dirname, 'orcad-entry.ts'), 'utf8')
+  const install = entry.indexOf('closeOrcadObservability = installOrcadObservability()')
+  expect(install).toBeGreaterThan(-1)
+  expect(install).toBeLessThan(entry.indexOf('new OrcaRuntimeService('))
+  const quit = entry.indexOf('      runOrcadQuitHandlers()\n')
+  expect(quit).toBeGreaterThan(-1)
+  expect(entry.indexOf('      closeOrcadObservability()\n', quit)).toBeGreaterThan(quit)
+})
diff --git a/src/main/orcad/orcad-observability.ts b/src/main/orcad/orcad-observability.ts
new file mode 100644
index 00000000000..4200180a2c9
--- /dev/null
+++ b/src/main/orcad/orcad-observability.ts
@@ -0,0 +1,19 @@
+// orcad's local trace file: the desktop's sink and consent gates under orcad's own data root and
+// its own name (`<data-root>/logs/orcad.trace.ndjson`), so a headless host's spans, its reported
+// structured-chat failures among them, reach a file and not only the supervisor's stderr.
+
+import process from 'node:process'
+import { flushObservability, initObservability, shutdownObservability } from '../observability'
+import { getOrcadTraceFilePath } from '../observability/logs-directory'
+
+/** Installed before the runtime, so its first span lands. Returns the close, which the host runs
+ *  last in its cleanup so every quit handler's spans land too. */
+export function installOrcadObservability(): () => void {
+  initObservability({ traceFilePath: getOrcadTraceFilePath() })
+  // `exit` runs synchronously on process.exit and after an uncaught exception; no cleanup does.
+  process.once('exit', flushObservability)
+  return () => {
+    process.off('exit', flushObservability)
+    void shutdownObservability()
+  }
+}
diff --git a/src/main/runtime/agent-session-legacy-record-import.test.ts b/src/main/runtime/agent-session-legacy-record-import.test.ts
index da09cb2257d..bf2156d0710 100644
--- a/src/main/runtime/agent-session-legacy-record-import.test.ts
+++ b/src/main/runtime/agent-session-legacy-record-import.test.ts
@@ -17,10 +17,10 @@ import {
 } from '../../shared/agent-session-record.test-fixture'
 import { journalPragmaNumber } from '../native-chat/agent-session-journal/journal-database'
 import type { JournalHostDatabase } from '../native-chat/agent-session-journal/journal-host-database'
-import type { LegacyAgentSessionRecordImportReport } from './agent-session-legacy-record-import'
 import { AgentSessionRecordStore } from './agent-session-record-store'
 import { legacyAgentSessionStorePath } from './agent-session-record-store-file'
 import { openStructuredAgentSessionJournalDatabase } from './structured-agent-session-journal-open'
+import { recordingStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 const NOW = 1_800_000_000_000
 const ALPHA = 'session-alpha'
@@ -96,15 +96,19 @@ async function writeLegacy(file: unknown, backup?: unknown): Promise<void> {
 async function install(): Promise<{
   database: JournalHostDatabase
   store: AgentSessionRecordStore
-  reports: LegacyAgentSessionRecordImportReport[]
+  reports: unknown[]
 }> {
-  const reports: LegacyAgentSessionRecordImportReport[] = []
+  const log = recordingStructuredAgentSessionLogger()
   const database = await openStructuredAgentSessionJournalDatabase({
+    logger: log.logger,
     stateDirectory: root,
-    hostId: 'local',
-    onLegacyRecordImportReport: (report) => reports.push(report)
+    hostId: 'local'
   })
   opened.push(database)
+  // Each report reaches the log as one entry under its scope, its kind as the outcome.
+  const reports = log.entries
+    .filter((entry) => entry.fields.scope === 'legacy-record-import')
+    .map(({ fields: { scope: _scope, outcome, ...rest } }) => ({ kind: outcome, ...rest }))
   return {
     database,
     store: AgentSessionRecordStore.open({ journalDatabase: database, hostId: 'local' }),
diff --git a/src/main/runtime/claude-structured-session-integration.test.ts b/src/main/runtime/claude-structured-session-integration.test.ts
index 47199f6199f..a12fc06c479 100644
--- a/src/main/runtime/claude-structured-session-integration.test.ts
+++ b/src/main/runtime/claude-structured-session-integration.test.ts
@@ -27,6 +27,7 @@ import {
   stopStructuredAgentSessionRuntime,
   waitForStructuredAgentSessionRecovery
 } from './structured-agent-session-runtime'
+import { createStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 
 const SESSION = 'claude-integration-1'
 const PROVIDER_SESSION = claudeSessionIdForOrcaSession(SESSION)
@@ -234,6 +235,7 @@ beforeEach(async () => {
     publishStructuredAgentSessionTab: vi.fn(),
     ensureStructuredAgentSessionHost: () =>
       ensureStructuredAgentSessionHost({
+        logger: createStructuredAgentSessionLogger(),
         stateDirectory: root,
         hostId: 'local',
         claimKeyId: 'key-1',
diff --git a/src/main/runtime/orca-runtime-close-structured-agent-session-tab.ts b/src/main/runtime/orca-runtime-close-structured-agent-session-tab.ts
index 3b3510916ba..eae4b7b7e32 100644
--- a/src/main/runtime/orca-runtime-close-structured-agent-session-tab.ts
+++ b/src/main/runtime/orca-runtime-close-structured-agent-session-tab.ts
@@ -27,7 +27,11 @@ export class OrcaRuntimeWithCloseStructuredAgentSessionTab extends OrcaRuntimeWi
         // The restore index is bookkeeping: one that cannot be written (a newer Orca's records, a
         // failing disk) is reported, and the tab still closes.
         await host.setSessionTabVisibility(tab.sessionId, false).catch((error: unknown) => {
-          console.warn('[structured-agent-session] recording a closed chat tab failed', error)
+          host.deps.logger.warn('recording a closed chat tab failed', {
+            scope: 'tab-visibility-close',
+            sessionId: tab.sessionId,
+            error
+          })
         })
       }
     }
diff --git a/src/main/runtime/orca-runtime-get-worktree-ps.ts b/src/main/runtime/orca-runtime-get-worktree-ps.ts
index adcd47baad3..b25ce381def 100644
--- a/src/main/runtime/orca-runtime-get-worktree-ps.ts
+++ b/src/main/runtime/orca-runtime-get-worktree-ps.ts
@@ -14,6 +14,7 @@ import { compareWorktreePs } from './runtime-worktree-status-projection'
 import type { Repo } from '../../shared/repo-types'
 import { enrichMissingRepoGitRemoteIdentities } from '../repo-git-remote-identity-enrichment'
 import { ensureStructuredAgentSessionHost as installStructuredAgentSessionHost } from './structured-agent-session-runtime'
+import { createStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 import { maybeAutoRenameWorkspaceOnFirstStructuredTurn } from '../agent-hooks/first-work-structured-session-rename'
 import { firstWorkRenameDeps } from '../agent-hooks/first-work-rename-runtime'
 import { getProfileUserDataPath } from '../orca-profiles/profile-storage-paths'
@@ -142,6 +143,8 @@ export class OrcaRuntimeWithGetWorktreePs extends OrcaRuntimeWithStartTuiIdleVis
       stateDirectory: getProfileUserDataPath(),
       hostId: LOCAL_EXECUTION_HOST_ID,
       claimKeyId: this.agentSessionClaimSigner.keyId,
+      // The host's local trace file (the desktop's or orcad's own), plus the console.
+      logger: createStructuredAgentSessionLogger(),
       // Resolves folder workspaces as well as git worktrees, so a chat session
       // in a plain folder lands in the folder rather than failing to resolve.
       resolveWorkspacePath: async (workspaceId) =>
diff --git a/src/main/runtime/orca-runtime-restore-structured-agent-session-tabs-once.ts b/src/main/runtime/orca-runtime-restore-structured-agent-session-tabs-once.ts
index f8845221e66..61c2e0b3605 100644
--- a/src/main/runtime/orca-runtime-restore-structured-agent-session-tabs-once.ts
+++ b/src/main/runtime/orca-runtime-restore-structured-agent-session-tabs-once.ts
@@ -125,7 +125,11 @@ export class OrcaRuntimeWithRestoreStructuredAgentSessionTabsOnce extends OrcaRu
       await host
         .setSessionTabVisibility(input.sessionId, true, ...(input.tabId ? [input.tabId] : []))
         .catch((error: unknown) => {
-          console.warn('[structured-agent-session] recording an opened chat tab failed', error)
+          host.deps.logger.warn('recording an opened chat tab failed', {
+            scope: 'tab-visibility-open',
+            sessionId: input.sessionId,
+            error
+          })
         })
     }
     this.projectStructuredAgentSessionTab(input)
diff --git a/src/main/runtime/orca-runtime-structured-status-sink-wiring.test.ts b/src/main/runtime/orca-runtime-structured-status-sink-wiring.test.ts
index b931af57463..9936c954b5b 100644
--- a/src/main/runtime/orca-runtime-structured-status-sink-wiring.test.ts
+++ b/src/main/runtime/orca-runtime-structured-status-sink-wiring.test.ts
@@ -1,6 +1,13 @@
-import { describe, expect, it, vi } from 'vitest'
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import type { StructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 
-const installed = vi.hoisted(() => ({ deps: null as Record<string, unknown> | null }))
+const installed = vi.hoisted(() => {
+  const state: {
+    deps: Record<string, unknown> | null
+    logger: StructuredAgentSessionLogger | null
+  } = { deps: null, logger: null }
+  return state
+})
 
 vi.mock('electron', () => ({
   BrowserWindow: { fromId: vi.fn(() => null) },
@@ -10,14 +17,18 @@ vi.mock('electron', () => ({
 }))
 
 vi.mock('./structured-agent-session-runtime', () => ({
-  ensureStructuredAgentSessionHost: vi.fn(async (deps: Record<string, unknown>) => {
-    installed.deps = deps
-  })
+  ensureStructuredAgentSessionHost: vi.fn(
+    async (deps: Record<string, unknown> & { logger: StructuredAgentSessionLogger }) => {
+      installed.deps = deps
+      installed.logger = deps.logger
+    }
+  )
 }))
 
 import { readFileSync } from 'node:fs'
 import { join } from 'node:path'
 import { OrcaRuntimeService } from './orca-runtime'
+import { _resetTracerForTests, setActiveSink } from '../observability/tracer'
 import type { StructuredAgentSessionStatusSink } from '../native-chat/agent-session-wire/structured-agent-session-status-feed'
 
 type OrcaRuntimeDeps = NonNullable<ConstructorParameters<typeof OrcaRuntimeService>[2]>
@@ -78,6 +89,11 @@ describe('every host that constructs a runtime wires the agent-status store', ()
 })
 
 describe('structured status sink wiring', () => {
+  afterEach(() => {
+    _resetTracerForTests()
+    vi.restoreAllMocks()
+  })
+
   it('hands the host the sink the runtime was constructed with', async () => {
     installed.deps = null
     const sink: StructuredAgentSessionStatusSink = { publish: vi.fn(), forget: vi.fn() }
@@ -88,6 +104,32 @@ describe('structured status sink wiring', () => {
     expect(installed.deps?.['statusSink']).toBe(sink)
   })
 
+  // The runtime class does not typecheck its own calls, so the required logger is pinned here:
+  // a logger that writes nowhere would pass every host test while the desktop dropped failures.
+  it('hands the host the trace-file logger', async () => {
+    installed.logger = null
+    const push = vi.fn()
+    setActiveSink({ push, flush: () => {}, close: () => {} })
+    vi.spyOn(console, 'warn').mockImplementation(() => undefined)
+    const runtime = new OrcaRuntimeService()
+
+    await runtime.ensureStructuredAgentSessionHost()
+    const installedLogger = (): StructuredAgentSessionLogger | null => installed.logger
+    installedLogger()?.warn('renewing a chat lease failed', {
+      scope: 'lease-renewal',
+      sessionId: 'session-1',
+      error: new Error('database is locked')
+    })
+
+    expect(push).toHaveBeenCalledWith(
+      expect.objectContaining({
+        name: 'agentSession.lease-renewal',
+        attributes: expect.objectContaining({ sessionId: 'session-1' }),
+        exit: expect.objectContaining({ _tag: 'Failure' })
+      })
+    )
+  })
+
   it('installs without a sink when none was provided', async () => {
     installed.deps = null
     const runtime = new OrcaRuntimeService()
diff --git a/src/main/runtime/rpc/methods/agent-launch-structured-prompt.test.ts b/src/main/runtime/rpc/methods/agent-launch-structured-prompt.test.ts
index 4d919df556e..1b591051936 100644
--- a/src/main/runtime/rpc/methods/agent-launch-structured-prompt.test.ts
+++ b/src/main/runtime/rpc/methods/agent-launch-structured-prompt.test.ts
@@ -11,15 +11,21 @@ import { commitStructuredAgentSessionLaunchPrompt } from './agent-launch-structu
 import { structuredAgentSessionPayloadFingerprint } from '../../../../shared/structured-agent-session-mutation'
 import { structuredAgentSessionSendBody } from '../../../../shared/structured-agent-session-outbox'
 import type { StructuredAgentSessionHost } from '../../../native-chat/agent-session-wire/structured-agent-session-host'
+import { recordingStructuredAgentSessionLogger } from '../../../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 const CALLER = { callerKey: 'trusted-local:runtime' }
 
 function hostWith(
   send: ReturnType<typeof vi.fn>,
-  journalSnapshot: ReturnType<typeof vi.fn> = vi.fn(() => ({ submissions: [] }))
+  journalSnapshot: ReturnType<typeof vi.fn> = vi.fn(() => ({ submissions: [] })),
+  log = recordingStructuredAgentSessionLogger()
 ): StructuredAgentSessionHost {
-  // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: the stub implements the only method this module reaches; any other would throw rather than read a wrong value.
-  return { send, journalSnapshot } as unknown as StructuredAgentSessionHost
+  // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: the stub implements the only members this module reaches; any other would throw rather than read a wrong value.
+  return {
+    send,
+    journalSnapshot,
+    deps: { logger: log.logger }
+  } as unknown as StructuredAgentSessionHost
 }
 
 function commit(host: StructuredAgentSessionHost | null, text = 'do the thing') {
@@ -80,11 +86,15 @@ describe('committing a launch prompt', () => {
   })
 
   it('claims nothing, and does not fail the launch, when no row was committed', async () => {
-    vi.spyOn(console, 'warn').mockImplementation(() => {})
+    const log = recordingStructuredAgentSessionLogger()
+    const failure = new Error('host gone')
     const send = vi.fn(async () => {
-      throw new Error('host gone')
+      throw failure
     })
-    await expect(commit(hostWith(send))).resolves.toBeNull()
+    await expect(commit(hostWith(send, undefined, log))).resolves.toBeNull()
+    expect(log.entries.map((entry) => entry.fields)).toEqual([
+      { scope: 'launch-prompt', sessionId: 'sess-1', error: failure }
+    ])
   })
 
   it('sends nothing when there is no host or no text', async () => {
diff --git a/src/main/runtime/rpc/methods/agent-launch-structured-prompt.ts b/src/main/runtime/rpc/methods/agent-launch-structured-prompt.ts
index 11762137ba2..00c779fffe0 100644
--- a/src/main/runtime/rpc/methods/agent-launch-structured-prompt.ts
+++ b/src/main/runtime/rpc/methods/agent-launch-structured-prompt.ts
@@ -72,7 +72,11 @@ export async function commitStructuredAgentSessionLaunchPrompt(args: {
     } catch {
       // The host may have gone away before the snapshot; the caller retains the text in that case.
     }
-    console.warn('[agent-launch] the session was created, its launch prompt was not sent', error)
+    args.host.deps.logger.warn("sending a created chat's launch prompt failed", {
+      scope: 'launch-prompt',
+      sessionId: args.sessionId,
+      error
+    })
     return null
   }
 }
diff --git a/src/main/runtime/rpc/methods/structured-agent-session-adoption-replay.test.ts b/src/main/runtime/rpc/methods/structured-agent-session-adoption-replay.test.ts
index 64c7ec1c8b1..6d1ddf9f359 100644
--- a/src/main/runtime/rpc/methods/structured-agent-session-adoption-replay.test.ts
+++ b/src/main/runtime/rpc/methods/structured-agent-session-adoption-replay.test.ts
@@ -13,6 +13,7 @@ import type { RpcRequest, RpcResponse } from '../core'
 import { RpcDispatcher } from '../dispatcher'
 import { STRUCTURED_AGENT_SESSION_METHODS } from './structured-agent-session'
 import { openTestJournalHostDatabase } from '../../../native-chat/agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from '../../../native-chat/agent-session-wire/structured-agent-session-logger'
 
 const SESSION = 'session-adoption-replay'
 const THREAD = 'thread-adoption-replay'
@@ -184,6 +185,7 @@ describe('committed adopting create RPC replay', () => {
     const store = await openTestAgentSessionRecordStore(root)
     const sessionAdapter = adapter()
     host = new StructuredAgentSessionHost({
+      logger: createStructuredAgentSessionLogger(),
       store,
       adapter: sessionAdapter,
       journalDatabase: openTestJournalHostDatabase(root),
diff --git a/src/main/runtime/rpc/methods/structured-agent-session-at-rest.test.ts b/src/main/runtime/rpc/methods/structured-agent-session-at-rest.test.ts
index 9cbad804cd5..b846be96dd2 100644
--- a/src/main/runtime/rpc/methods/structured-agent-session-at-rest.test.ts
+++ b/src/main/runtime/rpc/methods/structured-agent-session-at-rest.test.ts
@@ -287,8 +287,11 @@ describe('the accessor', () => {
     const warn = vi.spyOn(console, 'warn').mockImplementation(() => undefined)
     const logged = (): unknown[] =>
       warn.mock.calls
-        .filter(([line]) => line === '[agent-session] opening the conversation for a read failed:')
-        .map(([, error]) => error)
+        .filter(
+          ([line]) =>
+            line === '[agent-session] open-for-read: opening the conversation for a read failed'
+        )
+        .map(([, fields]) => fields?.error)
     const reconnect = async (): Promise<RpcResponse[]> => [
       ...(await call('agentSession.subscribe', { sessionId: SESSION })),
       ...(await call('agentSession.history', { sessionId: SESSION, direction: 'tail' }))
diff --git a/src/main/runtime/rpc/methods/structured-agent-session-create-tab-publication.test.ts b/src/main/runtime/rpc/methods/structured-agent-session-create-tab-publication.test.ts
new file mode 100644
index 00000000000..cf708f37491
--- /dev/null
+++ b/src/main/runtime/rpc/methods/structured-agent-session-create-tab-publication.test.ts
@@ -0,0 +1,41 @@
+import { expect, it, vi } from 'vitest'
+import type { AgentSessionAttachParams } from '../../../native-chat/agent-session-wire/structured-agent-session-attach'
+import type { StructuredAgentSessionHost } from '../../../native-chat/agent-session-wire/structured-agent-session-host'
+import { recordingStructuredAgentSessionLogger } from '../../../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
+import type { OrcaRuntimeService } from '../../orca-runtime'
+import { commitStructuredAgentSessionCreate } from './structured-agent-session-create'
+
+// A chat created whose tab could not be published is answered as unconfirmed; the cause is logged.
+it('logs a created chat whose tab could not be published, and answers it unconfirmed', async () => {
+  const log = recordingStructuredAgentSessionLogger()
+  const failure = new Error('tab write failed')
+  // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: the stub implements the only members the commit reaches past attach.
+  const host = {
+    attach: vi.fn(async () => ({ ok: true, value: { sessionId: 'session-1' } })),
+    getSessionTabId: vi.fn(() => null),
+    deps: { logger: log.logger }
+  } as unknown as StructuredAgentSessionHost
+  // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: the commit reaches only the tab publication on the runtime.
+  const runtime = {
+    publishStructuredAgentSessionTab: vi.fn(async () => {
+      throw failure
+    })
+  } as unknown as OrcaRuntimeService
+
+  const result = await commitStructuredAgentSessionCreate({
+    runtime,
+    caller: { callerKey: 'client-1' },
+    prepared: {
+      host,
+      // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: the stubbed attach reads none of it.
+      attachParams: {} as AgentSessionAttachParams,
+      tab: { workspaceId: 'workspace-1', agent: 'codex' }
+    },
+    activate: true
+  })
+
+  expect(result).toMatchObject({ ok: false, refusal: { details: { reason: 'tabUnconfirmed' } } })
+  expect(log.entries.map((entry) => entry.fields)).toEqual([
+    { scope: 'create-tab-publication', sessionId: 'session-1', error: failure }
+  ])
+})
diff --git a/src/main/runtime/rpc/methods/structured-agent-session-create.ts b/src/main/runtime/rpc/methods/structured-agent-session-create.ts
index 0c3b7b08713..1d0899a014d 100644
--- a/src/main/runtime/rpc/methods/structured-agent-session-create.ts
+++ b/src/main/runtime/rpc/methods/structured-agent-session-create.ts
@@ -142,7 +142,11 @@ export async function commitStructuredAgentSessionCreate(args: {
       ...(surfaceTabId ? { tabId: surfaceTabId } : {})
     })
   } catch (error) {
-    console.warn('[agent-session] create committed before tab publication failed', error)
+    prepared.host.deps.logger.warn('publishing the tab of a created chat failed', {
+      scope: 'create-tab-publication',
+      sessionId: result.value.sessionId,
+      error
+    })
     return {
       ok: false,
       refusal: refuse(
diff --git a/src/main/runtime/rpc/methods/structured-agent-session-hold.test.ts b/src/main/runtime/rpc/methods/structured-agent-session-hold.test.ts
index 45c01c2c63a..446fb107411 100644
--- a/src/main/runtime/rpc/methods/structured-agent-session-hold.test.ts
+++ b/src/main/runtime/rpc/methods/structured-agent-session-hold.test.ts
@@ -28,6 +28,7 @@ import { STRUCTURED_AGENT_SESSION_METHODS } from './structured-agent-session'
 import { agentSessionFailureFact } from '../../../../shared/agent-session-failure'
 import { agentSessionFailureWords } from '../../../../shared/agent-session-failure-words'
 import { openTestJournalHostDatabase } from '../../../native-chat/agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from '../../../native-chat/agent-session-wire/structured-agent-session-logger'
 
 const CONNECTION = 'connection-1'
 const CLIENT = {
@@ -78,6 +79,7 @@ beforeEach(async () => {
   }))
   store = await openTestAgentSessionRecordStore(root)
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: {
       acquire,
diff --git a/src/main/runtime/rpc/methods/structured-agent-session-precommit-refusal.test.ts b/src/main/runtime/rpc/methods/structured-agent-session-precommit-refusal.test.ts
index f34ecb5d6cd..17aadf32a80 100644
--- a/src/main/runtime/rpc/methods/structured-agent-session-precommit-refusal.test.ts
+++ b/src/main/runtime/rpc/methods/structured-agent-session-precommit-refusal.test.ts
@@ -4,6 +4,7 @@
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 import type { StructuredAgentSessionHost } from '../../../native-chat/agent-session-wire/structured-agent-session-host'
 import { setStructuredAgentSessionHost } from '../../../native-chat/agent-session-wire/structured-agent-session-registry'
+import { recordingStructuredAgentSessionLogger } from '../../../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 import { computeAgentSessionPayloadFingerprint } from '../../../../shared/agent-session-mutation-envelope'
 import { isDefinitiveAgentSessionCreateRefusal } from '../../../../shared/agent-session-definitive-refusal'
 import { STRUCTURED_AGENT_SESSION_RUNTIME_CAPABILITY } from '../../../../shared/protocol-version'
@@ -49,7 +50,11 @@ function hostStub(): StructuredAgentSessionHost {
     cursor: { epoch: 'epoch-a', sequence: 0 },
     value: { sessionId: SESSION, fence: 1, page: {}, unconfirmedClientMessageIds: [] }
   }))
-  return { attach } as unknown as StructuredAgentSessionHost
+  // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: create reaches only attach, and the logger a failure past it reports to.
+  return {
+    attach,
+    deps: { logger: recordingStructuredAgentSessionLogger().logger }
+  } as unknown as StructuredAgentSessionHost
 }
 
 const resolvedIntent = {
diff --git a/src/main/runtime/rpc/methods/structured-agent-session-rpc.test-fixture.ts b/src/main/runtime/rpc/methods/structured-agent-session-rpc.test-fixture.ts
index 85d3e2a5b4b..57606c8c456 100644
--- a/src/main/runtime/rpc/methods/structured-agent-session-rpc.test-fixture.ts
+++ b/src/main/runtime/rpc/methods/structured-agent-session-rpc.test-fixture.ts
@@ -19,6 +19,8 @@ import {
 import type { RpcRequest, RpcResponse } from '../core'
 import { RpcDispatcher } from '../dispatcher'
 import { STRUCTURED_AGENT_SESSION_METHODS } from './structured-agent-session'
+import { createStructuredAgentSessionLogger } from '../../../native-chat/agent-session-wire/structured-agent-session-logger'
+import { recordingStructuredAgentSessionLogger } from '../../../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 export const SESSION = 'session-alpha'
 export const FINGERPRINT = 'f'.repeat(64)
@@ -94,6 +96,7 @@ export const STATUS_ITEMS: AgentJournalRenderItem[] = [
 /** One indexed session over a journal that reads back fixed items; the projection is real. */
 function statusFeed(): StructuredAgentSessionStatusFeed {
   return new StructuredAgentSessionStatusFeed({
+    logger: createStructuredAgentSessionLogger(),
     sessions: new Map([
       [
         STATUS_SESSION,
@@ -206,6 +209,8 @@ export function hostStub(): StructuredAgentSessionHost {
     ),
     unsubscribe: vi.fn()
   })
+  // Not a call: the logger the host hands a runtime caller that reports for it.
+  Reflect.set(hostCalls, 'deps', { logger: recordingStructuredAgentSessionLogger().logger })
   return hostCalls as unknown as StructuredAgentSessionHost
 }
 
diff --git a/src/main/runtime/rpc/methods/structured-chat-tab-table.test.ts b/src/main/runtime/rpc/methods/structured-chat-tab-table.test.ts
index f437e806899..c97672269eb 100644
--- a/src/main/runtime/rpc/methods/structured-chat-tab-table.test.ts
+++ b/src/main/runtime/rpc/methods/structured-chat-tab-table.test.ts
@@ -38,6 +38,7 @@ import { STRUCTURED_AGENT_SESSION_METHODS } from './structured-agent-session'
 import { commitStructuredAgentSessionCreate } from './structured-agent-session-create'
 import { closeStructuredAgentSessionChild } from '../../structured-agent-session-close'
 import { openTestJournalHostDatabase } from '../../../native-chat/agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from '../../../native-chat/agent-session-wire/structured-agent-session-logger'
 
 const WORKTREE = `id:${HOST_TEST_LOCATION.workspaceId}`
 const SOURCE_TAB = `structured-agent-session-${HOST_TEST_SESSION}`
@@ -93,6 +94,7 @@ function providerAdapter(): StructuredAgentSessionAdapter {
 async function openHost(): Promise<void> {
   store = await openTestAgentSessionRecordStore(directory)
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: providerAdapter(),
     journalDatabase: openTestJournalHostDatabase(directory),
@@ -540,8 +542,8 @@ describe('a chat tab over records a newer Orca wrote', () => {
 
     expect((await snapshot()).activeTabId).toBe(`agent-session:${HOST_TEST_SESSION}`)
     expect(warn).toHaveBeenCalledWith(
-      '[structured-agent-session] recording an opened chat tab failed',
-      expect.anything()
+      '[agent-session] tab-visibility-open: recording an opened chat tab failed',
+      expect.objectContaining({ scope: 'tab-visibility-open', sessionId: HOST_TEST_SESSION })
     )
   })
 })
@@ -559,8 +561,8 @@ describe('a chat tab whose restore index cannot be written', () => {
     expect(created.ok ? created.value.tabId : null).toBeUndefined()
     expect((await snapshot()).activeTabId).toBe(`agent-session:${HOST_TEST_SESSION}`)
     expect(warn).toHaveBeenCalledWith(
-      '[structured-agent-session] recording an opened chat tab failed',
-      failure
+      '[agent-session] tab-visibility-open: recording an opened chat tab failed',
+      { scope: 'tab-visibility-open', sessionId: HOST_TEST_SESSION, error: failure }
     )
     expect(store.getSessionTabId(HOST_TEST_SESSION)).toBeNull()
   })
diff --git a/src/main/runtime/runtime-worktree-agent-rows-verdict.test.ts b/src/main/runtime/runtime-worktree-agent-rows-verdict.test.ts
index 0d9180dc3e5..25379632875 100644
--- a/src/main/runtime/runtime-worktree-agent-rows-verdict.test.ts
+++ b/src/main/runtime/runtime-worktree-agent-rows-verdict.test.ts
@@ -20,6 +20,7 @@ import { StructuredAgentSessionStatusFeed } from '../native-chat/agent-session-w
 import { indexedStatusFeedSession } from '../native-chat/agent-session-wire/structured-agent-session-status-feed-test-session'
 import { attachRuntimeWorktreeAgentRows } from './runtime-worktree-agent-rows'
 import { collectRuntimeWorktreeAgentSources } from './runtime-worktree-agent-sources'
+import { createStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 
 vi.mock('../telemetry/client', () => ({ track: vi.fn() }))
 vi.mock('../telemetry/cohort-classifier', () => ({
@@ -76,6 +77,7 @@ async function openJournal(): Promise<AgentSessionJournal> {
 function publishedSummary(journal: AgentSessionJournal): AgentSessionStatusSummary {
   const session = indexedStatusFeedSession({ journal })
   const feed = new StructuredAgentSessionStatusFeed({
+    logger: createStructuredAgentSessionLogger(),
     sessions: new Map([[SESSION, session]]),
     getRecord: () => agentSessionRecordFixture(),
     now: () => 1_000
diff --git a/src/main/runtime/runtime-worktree-structured-agent-rows-liveness.test.ts b/src/main/runtime/runtime-worktree-structured-agent-rows-liveness.test.ts
index 50e974f1eb5..5afd2d2e770 100644
--- a/src/main/runtime/runtime-worktree-structured-agent-rows-liveness.test.ts
+++ b/src/main/runtime/runtime-worktree-structured-agent-rows-liveness.test.ts
@@ -11,6 +11,7 @@ import type { AgentSessionStatusSummary } from '../../shared/agent-session-wire'
 import type { RuntimeWorktreePsSummary } from '../../shared/runtime-types'
 import { AgentHookServer, _internals } from '../agent-hooks/server'
 import { attachRuntimeWorktreeAgentRows } from './runtime-worktree-agent-rows'
+import { createStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 
 vi.mock('../telemetry/client', () => ({ track: vi.fn() }))
 vi.mock('../telemetry/cohort-classifier', () => ({
@@ -106,6 +107,7 @@ async function awaitingApproval() {
   const store = new AgentHookServer()
   const published: AgentSessionStatusSummary[] = []
   const feed = new StructuredAgentSessionStatusFeed({
+    logger: createStructuredAgentSessionLogger(),
     sessions,
     getRecord: () => null,
     now: () => Date.now(),
diff --git a/src/main/runtime/structured-agent-session-close.test.ts b/src/main/runtime/structured-agent-session-close.test.ts
index 948bb01cce2..500a6cd1beb 100644
--- a/src/main/runtime/structured-agent-session-close.test.ts
+++ b/src/main/runtime/structured-agent-session-close.test.ts
@@ -9,6 +9,7 @@
 
 import { beforeEach, describe, expect, it, vi } from 'vitest'
 import type { AgentSessionRecord } from '../../shared/agent-session-record'
+import { recordingStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 const hostRef: { current: unknown } = { current: null }
 
@@ -85,8 +86,10 @@ function installHost(options: HostOptions = {}) {
       throw new Error('the event sink could not be flushed')
     }
   })
+  const log = recordingStructuredAgentSessionLogger()
   hostRef.current = {
     deps: {
+      logger: log.logger,
       store: {
         getRecord: (id: string) => (id === SESSION ? entry : null),
         getSessionTabId: (id: string) => {
@@ -101,7 +104,7 @@ function installHost(options: HostOptions = {}) {
     setSessionTabVisibility,
     close
   }
-  return { close, setSessionTabVisibility, visible }
+  return { close, setSessionTabVisibility, visible, log }
 }
 
 describe('closeStructuredAgentSessionChild tab-visibility rollback', () => {
@@ -207,11 +210,11 @@ describe('closeStructuredAgentSessionChild tab-visibility rollback', () => {
   })
 
   it('keeps the original failure when the restore itself throws', async () => {
-    const warn = vi.spyOn(console, 'warn').mockImplementation(() => {})
     const host = installHost({ stuck: true })
+    const restoreFailure = new Error('agent_session_identity_required')
     host.setSessionTabVisibility.mockImplementation(async (_sessionId, isVisible) => {
       if (isVisible) {
-        throw new Error('agent_session_identity_required')
+        throw restoreFailure
       }
     })
 
@@ -220,7 +223,9 @@ describe('closeStructuredAgentSessionChild tab-visibility rollback', () => {
     expect(outcome.stopped).toBe(false)
     expect(outcome.closeAttempted).toBe(true)
     expect(outcome.reason).not.toContain('agent_session_identity_required')
-    expect(warn).toHaveBeenCalled()
+    expect(host.log.entries.map((entry) => entry.fields)).toEqual([
+      { scope: 'close-tab-restore', sessionId: SESSION, error: restoreFailure }
+    ])
   })
 
   it('claims nothing when the visible-tab index cannot be read', async () => {
diff --git a/src/main/runtime/structured-agent-session-close.ts b/src/main/runtime/structured-agent-session-close.ts
index 3ee8f265c4d..16bf8cce71d 100644
--- a/src/main/runtime/structured-agent-session-close.ts
+++ b/src/main/runtime/structured-agent-session-close.ts
@@ -147,9 +147,10 @@ async function restorePersistedTabVisibility(
   try {
     await host.setSessionTabVisibility?.(sessionId, true, tabId)
   } catch (error) {
-    console.warn(
-      `[structured-session-close] could not restore the chat tab for ${sessionId} after a failed close`,
+    host.deps.logger.warn('restoring the chat tab after a failed close failed', {
+      scope: 'close-tab-restore',
+      sessionId,
       error
-    )
+    })
   }
 }
diff --git a/src/main/runtime/structured-agent-session-codex-turn-end-settlement.test.ts b/src/main/runtime/structured-agent-session-codex-turn-end-settlement.test.ts
index facd5e15b05..6545ffb2ecf 100644
--- a/src/main/runtime/structured-agent-session-codex-turn-end-settlement.test.ts
+++ b/src/main/runtime/structured-agent-session-codex-turn-end-settlement.test.ts
@@ -34,6 +34,7 @@ import {
   ensureStructuredAgentSessionHost,
   stopStructuredAgentSessionRuntime
 } from './structured-agent-session-runtime'
+import { createStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 
 // The turns a send or Stop is waiting on to open, so a test knows the wait began.
 const openWaits = vi.hoisted(() => {
@@ -217,6 +218,7 @@ beforeEach(async () => {
     return connection
   }
   host = await ensureStructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     stateDirectory: root,
     hostId: 'local',
     claimKeyId: 'key-1',
diff --git a/src/main/runtime/structured-agent-session-dispatch-followups.ts b/src/main/runtime/structured-agent-session-dispatch-followups.ts
new file mode 100644
index 00000000000..dbc5a31b0d1
--- /dev/null
+++ b/src/main/runtime/structured-agent-session-dispatch-followups.ts
@@ -0,0 +1,52 @@
+// What the runtime does when a provider settles a dispatch after the fact: a late answer to a send,
+// or the provider going idle with sends it never answered. Both run off the request that caused
+// them, so their failure has nobody to return to and is logged instead.
+
+import { DISPATCH_DOUBT_PROVIDER_IDLE } from '../native-chat/agent-session-journal/journal-dispatch-doubt-reasons'
+import type { StructuredAgentSessionHost } from '../native-chat/agent-session-wire/structured-agent-session-host'
+import type { StructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
+
+type DispatchFollowUpHost = Pick<
+  StructuredAgentSessionHost,
+  'settleLateDispatch' | 'releaseUnansweredDispatches'
+>
+
+export function createStructuredAgentSessionDispatchFollowUps(input: {
+  /** Null until the host is built: the adapters that call these are built first. */
+  host: () => DispatchFollowUpHost | null
+  logger: StructuredAgentSessionLogger
+}): {
+  onDispatchSettledLate: (
+    settlement: Parameters<StructuredAgentSessionHost['settleLateDispatch']>[0]
+  ) => void
+  releaseUnansweredDispatches: (input: { sessionId: string }) => void
+} {
+  const { logger } = input
+  return {
+    onDispatchSettledLate: (settlement) => {
+      void input
+        .host()
+        ?.settleLateDispatch(settlement)
+        .catch((error: unknown) =>
+          logger.warn('settling a dispatch the provider answered late failed', {
+            scope: 'late-settlement',
+            sessionId: settlement.sessionId,
+            error
+          })
+        )
+    },
+    // The provider going idle is what re-derives a doubted send; a late echo still accepts it.
+    releaseUnansweredDispatches: ({ sessionId }) => {
+      void input
+        .host()
+        ?.releaseUnansweredDispatches({ sessionId, reason: DISPATCH_DOUBT_PROVIDER_IDLE })
+        .catch((error: unknown) =>
+          logger.warn('releasing sends the idle provider never answered failed', {
+            scope: 'unanswered-dispatch',
+            sessionId,
+            error
+          })
+        )
+    }
+  }
+}
diff --git a/src/main/runtime/structured-agent-session-failure-logging.test.ts b/src/main/runtime/structured-agent-session-failure-logging.test.ts
new file mode 100644
index 00000000000..9a8d9edb96f
--- /dev/null
+++ b/src/main/runtime/structured-agent-session-failure-logging.test.ts
@@ -0,0 +1,340 @@
+// Failures the desktop host used to drop: it installed the runtime with no error callback, so
+// each of these reached nobody. Every one now lands in the required logger under its own scope.
+
+import { mkdtemp, rm } from 'node:fs/promises'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import { AGENT_JOURNAL_THREAD_SCOPE } from '../../shared/agent-session-journal-types'
+import type { AgentSessionJournal } from '../native-chat/agent-session-journal/journal-store'
+import type { StructuredAgentSessionHostDeps } from '../native-chat/agent-session-wire/structured-agent-session-host'
+import { StructuredAgentSessionHostRuntimeState } from '../native-chat/agent-session-wire/structured-agent-session-host-runtime-state'
+import {
+  StructuredAgentSessionDeliveryLoop,
+  type StructuredAgentSessionDeliveryLoopDeps
+} from '../native-chat/agent-session-wire/structured-agent-session-delivery-loop'
+import {
+  StructuredAgentSessionIdleSweep,
+  type StructuredAgentSessionIdleSweepDeps
+} from '../native-chat/agent-session-wire/structured-agent-session-idle-sweep'
+import {
+  StructuredAgentSessionQueuedMessageDrain,
+  type QueuedMessageDrainDeps
+} from '../native-chat/agent-session-wire/structured-agent-session-queued-messages'
+import {
+  createStructuredAgentSessionLogger,
+  neverThrowingStructuredAgentSessionLogger
+} from '../native-chat/agent-session-wire/structured-agent-session-logger'
+import { recordingStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
+import { _resetTracerForTests, setActiveSink } from '../observability/tracer'
+import { createStructuredAgentSessionDispatchFollowUps } from './structured-agent-session-dispatch-followups'
+import { createStructuredAgentSessionLifecycleDelivery } from './structured-agent-session-lifecycle-delivery'
+import {
+  STRUCTURED_AGENT_SESSION_LOGGER_REQUIRED,
+  ensureStructuredAgentSessionHost,
+  stopStructuredAgentSessionRuntime
+} from './structured-agent-session-runtime'
+
+const SESSION = 'session-1'
+
+function rejectingHost(error: Error) {
+  return {
+    settleLateDispatch: vi.fn(async () => {
+      throw error
+    }),
+    releaseUnansweredDispatches: vi.fn(async () => {
+      throw error
+    })
+  }
+}
+
+describe('failures the desktop host used to drop', () => {
+  it('logs a late dispatch settlement that fails', async () => {
+    const log = recordingStructuredAgentSessionLogger()
+    const error = new Error('settlement write failed')
+    const followUps = createStructuredAgentSessionDispatchFollowUps({
+      host: () => rejectingHost(error),
+      logger: log.logger
+    })
+
+    followUps.onDispatchSettledLate({
+      sessionId: SESSION,
+      clientMessageId: 'client-1',
+      state: 'unknown',
+      reason: 'provider went idle'
+    })
+
+    await vi.waitFor(() =>
+      expect(log.entries).toEqual([
+        {
+          level: 'warn',
+          message: 'settling a dispatch the provider answered late failed',
+          fields: { scope: 'late-settlement', sessionId: SESSION, error }
+        }
+      ])
+    )
+  })
+
+  it('logs releasing the sends an idle provider never answered when that fails', async () => {
+    const log = recordingStructuredAgentSessionLogger()
+    const error = new Error('release write failed')
+    const followUps = createStructuredAgentSessionDispatchFollowUps({
+      host: () => rejectingHost(error),
+      logger: log.logger
+    })
+
+    followUps.releaseUnansweredDispatches({ sessionId: SESSION })
+
+    await vi.waitFor(() =>
+      expect(log.entries).toEqual([
+        expect.objectContaining({
+          fields: { scope: 'unanswered-dispatch', sessionId: SESSION, error }
+        })
+      ])
+    )
+  })
+
+  it('logs a provider start or exit the host could not take', async () => {
+    const log = recordingStructuredAgentSessionLogger()
+    const error = new Error('host refused the event')
+    const lifecycle = createStructuredAgentSessionLifecycleDelivery({
+      handle: async () => {
+        throw error
+      },
+      logger: log.logger,
+      drainObservedExits: async () => {}
+    })
+
+    lifecycle.deliver({
+      type: 'started',
+      sessionId: SESSION,
+      fence: 1,
+      acquisitionGeneration: 'generation-1',
+      reportedOptions: { model: 'gpt-5' },
+      restoreSkippedOptions: []
+    })
+    lifecycle.deliver({
+      type: 'ended',
+      sessionId: SESSION,
+      reason: 'exited',
+      cause: 'unexpected-exit',
+      fence: 1,
+      acquisitionGeneration: 'generation-1'
+    })
+    await lifecycle.drain()
+
+    expect(log.entries.map((entry) => entry.fields)).toEqual([
+      { scope: 'lifecycle-started', sessionId: SESSION, error },
+      { scope: 'lifecycle-exit', sessionId: SESSION, error }
+    ])
+  })
+
+  it('logs provider events the chat journal would not take', async () => {
+    const log = recordingStructuredAgentSessionLogger()
+    // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: minting and binding a sink reads no other host dependency.
+    const runtime = new StructuredAgentSessionHostRuntimeState({
+      logger: log.logger
+    } as unknown as StructuredAgentSessionHostDeps)
+    const sink = runtime.eventSinkFor(SESSION)
+    const error = new Error('journal append failed')
+    // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: the sink calls only appendItem before it fails.
+    const journal = {
+      appendItem: async () => {
+        throw error
+      }
+    } as unknown as AgentSessionJournal
+    sink.bind({ journal, fence: 1, publish: () => {} })
+
+    sink.sink.appendItem(
+      { provider: 'codex', threadId: 'thread-1', turnId: 'turn-1', ordinal: 0 },
+      { kind: 'message', role: 'assistant', blocks: [{ type: 'text', text: 'hi' }] },
+      { turnScope: AGENT_JOURNAL_THREAD_SCOPE }
+    )
+    await expect(sink.drained()).resolves.toMatchObject({ ok: false })
+
+    expect(log.entries).toEqual([
+      expect.objectContaining({
+        level: 'error',
+        fields: { scope: 'journal-event-sink', sessionId: SESSION, error }
+      })
+    ])
+  })
+})
+
+describe('host collaborators log with their own scope', () => {
+  const error = new Error('serialize refused')
+  const rejectingSerialize = async (): Promise<never> => {
+    throw error
+  }
+
+  it('the delivery loop logs a failed delivery, and a failed recording of it', async () => {
+    const log = recordingStructuredAgentSessionLogger()
+    const loop = new StructuredAgentSessionDeliveryLoop(
+      // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: a step that rejects at its first serialize reads only these members.
+      {
+        serialize: rejectingSerialize,
+        trackStart: <T>(start: Promise<T>) => start,
+        logger: log.logger
+      } as unknown as StructuredAgentSessionDeliveryLoopDeps
+    )
+
+    loop.wake(SESSION)
+
+    await vi.waitFor(() =>
+      expect(log.entries.map((entry) => entry.fields)).toEqual([
+        { scope: 'delivery-loop', sessionId: SESSION, error },
+        { scope: 'delivery-loop-fail', sessionId: SESSION, error }
+      ])
+    )
+  })
+
+  it('the idle sweep logs a step that fails', async () => {
+    const log = recordingStructuredAgentSessionLogger()
+    const sweep = new StructuredAgentSessionIdleSweep(
+      // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: a tick whose serialize rejects reads only these members.
+      {
+        sessions: new Map([[SESSION, {}]]),
+        isDisposed: () => false,
+        serialize: rejectingSerialize,
+        logger: log.logger
+      } as unknown as StructuredAgentSessionIdleSweepDeps
+    )
+
+    await sweep.tick()
+
+    expect(log.entries.map((entry) => entry.fields)).toEqual([
+      { scope: 'idle-sweep', sessionId: SESSION, error }
+    ])
+  })
+
+  it('the queued-message drain logs a step that fails', async () => {
+    const log = recordingStructuredAgentSessionLogger()
+    const journal = { isReadOnly: false, queuedMessages: { settlementOwed: () => true } }
+    const drain = new StructuredAgentSessionQueuedMessageDrain(
+      // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: a schedule past the owed-settlement check reads only these members.
+      {
+        sessions: new Map([[SESSION, { journal }]]),
+        serialize: rejectingSerialize,
+        logger: log.logger
+      } as unknown as QueuedMessageDrainDeps
+    )
+
+    drain.schedule(SESSION)
+
+    await vi.waitFor(() =>
+      expect(log.entries.map((entry) => entry.fields)).toEqual([
+        { scope: 'queued-drain', sessionId: SESSION, error }
+      ])
+    )
+  })
+})
+
+describe('a logger that throws', () => {
+  it('never throws out of the report, and still prints what failed', () => {
+    const warn = vi.spyOn(console, 'warn').mockImplementation(() => undefined)
+    const loggerError = new Error('logger broke')
+    const logger = neverThrowingStructuredAgentSessionLogger({
+      warn: () => {
+        throw loggerError
+      },
+      error: () => {
+        throw loggerError
+      }
+    })
+    const error = new Error('what failed')
+
+    expect(() => logger.warn('a step failed', { scope: 'step', error })).not.toThrow()
+    expect(() => logger.error('a step failed', { scope: 'step', error })).not.toThrow()
+    expect(warn).toHaveBeenCalledWith('[agent-session] a step failed', {
+      scope: 'step',
+      error,
+      loggerError
+    })
+    warn.mockRestore()
+  })
+})
+
+describe('the production logger', () => {
+  afterEach(() => {
+    _resetTracerForTests()
+    vi.restoreAllMocks()
+  })
+
+  it('writes each entry to the trace file as a failed span named for its scope', () => {
+    const push = vi.fn()
+    setActiveSink({ push, flush: () => {}, close: () => {} })
+    vi.spyOn(console, 'warn').mockImplementation(() => undefined)
+
+    createStructuredAgentSessionLogger().warn('settling a late dispatch failed', {
+      scope: 'late-settlement',
+      sessionId: SESSION,
+      error: new Error('disk full')
+    })
+
+    expect(push).toHaveBeenCalledOnce()
+    expect(push.mock.calls[0]?.[0]).toMatchObject({
+      type: 'effect-span',
+      name: 'agentSession.late-settlement',
+      attributes: {
+        level: 'warn',
+        message: 'settling a late dispatch failed',
+        sessionId: SESSION
+      },
+      exit: { _tag: 'Failure', cause: expect.stringContaining('Error: disk full') }
+    })
+  })
+})
+
+describe('installing the runtime', () => {
+  let stateDirectory: string | null = null
+
+  afterEach(async () => {
+    await stopStructuredAgentSessionRuntime()
+    if (stateDirectory) {
+      await rm(stateDirectory, { recursive: true, force: true })
+      stateDirectory = null
+    }
+  })
+
+  it('refuses without a logger rather than dropping every failure', async () => {
+    const root = await mkdtemp(join(tmpdir(), 'orca-logger-wiring-'))
+    stateDirectory = root
+
+    await expect(
+      ensureStructuredAgentSessionHost(
+        // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: deliberately missing the logger, as a `@ts-nocheck` caller could drop it.
+        {
+          stateDirectory: root,
+          hostId: 'local',
+          claimKeyId: 'key-1',
+          resolveWorkspacePath: async () => root,
+          resolveClaudeAuthPolicy: () => ({ stripAuthEnv: true })
+        } as unknown as Parameters<typeof ensureStructuredAgentSessionHost>[0]
+      )
+    ).rejects.toThrow(STRUCTURED_AGENT_SESSION_LOGGER_REQUIRED)
+  })
+
+  it('hands the host a logger whose throw cannot reach the operation it reports', async () => {
+    const root = await mkdtemp(join(tmpdir(), 'orca-logger-wiring-'))
+    stateDirectory = root
+    vi.spyOn(console, 'warn').mockImplementation(() => undefined)
+    const host = await ensureStructuredAgentSessionHost({
+      stateDirectory: root,
+      hostId: 'local',
+      claimKeyId: 'key-1',
+      resolveWorkspacePath: async () => root,
+      resolveEnvironment: async () => ({}),
+      resolveClaudeAuthPolicy: () => ({ stripAuthEnv: true }),
+      logger: {
+        warn: () => {
+          throw new Error('logger broke')
+        },
+        error: () => {
+          throw new Error('logger broke')
+        }
+      }
+    })
+
+    expect(() => host.deps.logger.warn('a step failed', { scope: 'step' })).not.toThrow()
+  })
+})
diff --git a/src/main/runtime/structured-agent-session-host-refusal.test.ts b/src/main/runtime/structured-agent-session-host-refusal.test.ts
index d05c9a78422..3ef5965b4e8 100644
--- a/src/main/runtime/structured-agent-session-host-refusal.test.ts
+++ b/src/main/runtime/structured-agent-session-host-refusal.test.ts
@@ -25,8 +25,12 @@ import {
   ensureStructuredAgentSessionHost,
   stopStructuredAgentSessionRuntime
 } from './structured-agent-session-runtime'
+import { recordingStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 let root: string
+let log = recordingStructuredAgentSessionLogger()
+const openFailureLogs = () =>
+  log.entries.filter((entry) => entry.fields.scope === 'journal-database-open')
 
 // An in-process caller: the same build as the host, so the gate asks it for no capability.
 // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: the cleanup gate reads only `clientKind` and `clientCapabilities`.
@@ -34,6 +38,7 @@ const IN_PROCESS = {} as RpcContext
 
 function install(): ReturnType<typeof ensureStructuredAgentSessionHost> {
   return ensureStructuredAgentSessionHost({
+    logger: log.logger,
     stateDirectory: root,
     hostId: 'local',
     claimKeyId: 'key-1',
@@ -64,6 +69,7 @@ async function digest(path: string): Promise<string> {
 
 beforeEach(async () => {
   root = await mkdtemp(join(tmpdir(), 'orca-journal-host-refusal-'))
+  log = recordingStructuredAgentSessionLogger()
 })
 
 afterEach(async () => {
@@ -107,7 +113,6 @@ describe('a process whose journal will not open', () => {
     earlier.pragma('user_version = 2')
     earlier.close()
     const before = await digest(path)
-    const warn = vi.spyOn(console, 'warn').mockImplementation(() => undefined)
 
     for (let attempt = 0; attempt < 3; attempt += 1) {
       await expect(install()).rejects.toMatchObject({
@@ -118,8 +123,8 @@ describe('a process whose journal will not open', () => {
       reason: 'journalCorrupt',
       message: 'Unable to load this chat.'
     })
-    expect(warn).toHaveBeenCalledOnce()
-    const logged = String(warn.mock.calls[0]?.[1])
+    expect(openFailureLogs()).toHaveLength(1)
+    const logged = String(openFailureLogs()[0]?.fields.error)
     expect(logged).toContain(path)
     expect(logged).toContain('unreleased development build')
     expect(logged).toContain('Moving the file aside')
@@ -143,8 +148,6 @@ describe('a process whose journal will not open', () => {
 })
 
 describe('logging a journal that will not open', () => {
-  const OPEN_FAILED = '[structured-agent-session] opening the chat journal database failed'
-
   async function writeJunkJournal(): Promise<void> {
     const path = journalDatabasePath(root)
     await rm(`${path}-wal`, { force: true })
@@ -154,8 +157,6 @@ describe('logging a journal that will not open', () => {
 
   // Every chat request retries the open; the same failure each time is one log, not one per request.
   it('logs a repeated failure once, with its stack, and again after an open succeeds', async () => {
-    const warn = vi.spyOn(console, 'warn').mockImplementation(() => undefined)
-    const openFailureLogs = () => warn.mock.calls.filter(([message]) => message === OPEN_FAILED)
     await install()
     await stopStructuredAgentSessionRuntime()
     await writeJunkJournal()
@@ -166,8 +167,11 @@ describe('logging a journal that will not open', () => {
       })
     }
     expect(openFailureLogs()).toHaveLength(1)
-    expect(openFailureLogs()[0]?.[1]).toBeInstanceOf(Error)
-    expect(openFailureLogs()[0]?.[1]).toHaveProperty('stack', expect.stringContaining('\n'))
+    expect(openFailureLogs()[0]?.fields.error).toBeInstanceOf(Error)
+    expect(openFailureLogs()[0]?.fields.error).toHaveProperty(
+      'stack',
+      expect.stringContaining('\n')
+    )
 
     await unlink(journalDatabasePath(root))
     await install()
diff --git a/src/main/runtime/structured-agent-session-install-failure.test.ts b/src/main/runtime/structured-agent-session-install-failure.test.ts
index 4b00cdebda6..c00e9c6890f 100644
--- a/src/main/runtime/structured-agent-session-install-failure.test.ts
+++ b/src/main/runtime/structured-agent-session-install-failure.test.ts
@@ -11,6 +11,7 @@ import {
   ensureStructuredAgentSessionHost,
   stopStructuredAgentSessionRuntime
 } from './structured-agent-session-runtime'
+import { createStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 
 const mocks = vi.hoisted(() => ({ failWiring: vi.fn(() => false) }))
 
@@ -32,6 +33,7 @@ let root: string
 
 function install(): ReturnType<typeof ensureStructuredAgentSessionHost> {
   return ensureStructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     stateDirectory: root,
     hostId: 'local',
     claimKeyId: 'key-1',
diff --git a/src/main/runtime/structured-agent-session-integration.test.ts b/src/main/runtime/structured-agent-session-integration.test.ts
index cf41fdb1dfe..3d9e72f7404 100644
--- a/src/main/runtime/structured-agent-session-integration.test.ts
+++ b/src/main/runtime/structured-agent-session-integration.test.ts
@@ -43,6 +43,7 @@ import {
   ensureStructuredAgentSessionHost,
   stopStructuredAgentSessionRuntime
 } from './structured-agent-session-runtime'
+import { createStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 
 const journals = createTrackedJournalOpener()
 
@@ -330,6 +331,7 @@ beforeEach(async () => {
     publishStructuredAgentSessionTab: () => {},
     ensureStructuredAgentSessionHost: () =>
       ensureStructuredAgentSessionHost({
+        logger: createStructuredAgentSessionLogger(),
         stateDirectory: root,
         hostId: 'local',
         claimKeyId: 'key-1',
@@ -352,11 +354,9 @@ beforeEach(async () => {
         openCodexConnection: codex.openConnection,
         readProcessStartTime: async () => 1_700_000_000_000
       }).then(() => undefined),
-    registerOwnedSubscriptionCleanup: vi.fn((_id: string, dispose: () => void) => {
-      return {
-        releaseIfCurrent: dispose
-      }
-    })
+    registerOwnedSubscriptionCleanup: vi.fn((_id: string, dispose: () => void) => ({
+      releaseIfCurrent: dispose
+    }))
   }
   dispatcher = new RpcDispatcher({
     runtime: runtime as unknown as OrcaRuntimeService,
diff --git a/src/main/runtime/structured-agent-session-journal-open.ts b/src/main/runtime/structured-agent-session-journal-open.ts
index 6dd9d964d48..54c27fbfe96 100644
--- a/src/main/runtime/structured-agent-session-journal-open.ts
+++ b/src/main/runtime/structured-agent-session-journal-open.ts
@@ -9,11 +9,12 @@ import {
   type LegacyAgentSessionRecordImportReport
 } from './agent-session-legacy-record-import'
 import { recordStructuredAgentSessionHostInstallRefusal } from './structured-agent-session-host-refusal'
+import type { StructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 
 // Every chat request retries a failed open, so each distinct failure is logged once, with its stack.
 let lastLoggedOpenFailure: string | null = null
 
-function logOpenFailureOnce(error: unknown): void {
+function logOpenFailureOnce(logger: StructuredAgentSessionLogger, error: unknown): void {
   const failure =
     error instanceof Error
       ? `${'code' in error ? String(error.code) : ''}:${error.message}`
@@ -22,7 +23,10 @@ function logOpenFailureOnce(error: unknown): void {
     return
   }
   lastLoggedOpenFailure = failure
-  console.warn('[structured-agent-session] opening the chat journal database failed', error)
+  logger.error('opening the chat journal database failed', {
+    scope: 'journal-database-open',
+    error
+  })
 }
 
 /** The journal database. A refusal is recorded for the gate and thrown to the caller; the next
@@ -30,24 +34,36 @@ function logOpenFailureOnce(error: unknown): void {
 export async function openStructuredAgentSessionJournalDatabase(args: {
   stateDirectory: string
   hostId: string
-  onLegacyRecordImportReport: (report: LegacyAgentSessionRecordImportReport) => void
+  logger: StructuredAgentSessionLogger
 }): Promise<JournalHostDatabase> {
   try {
     const opened = await JournalHostDatabase.open(args.stateDirectory, async () =>
       legacyAgentSessionRecordImport(
         await readLegacyAgentSessionRecords(args.stateDirectory, args.hostId),
         args.hostId,
-        args.onLegacyRecordImportReport
+        (report) => reportLegacyRecordImport(args.logger, report)
       )
     )
     recordStructuredAgentSessionHostInstallRefusal(null)
     lastLoggedOpenFailure = null
     return opened
   } catch (error) {
-    logOpenFailureOnce(error)
+    logOpenFailureOnce(args.logger, error)
     // Nothing is renamed, deleted or rebuilt: the file is left exactly as it is.
     const refusal = journalOpenRefusalError(error)
     recordStructuredAgentSessionHostInstallRefusal(refusal)
     throw refusal
   }
 }
+
+function reportLegacyRecordImport(
+  logger: StructuredAgentSessionLogger,
+  report: LegacyAgentSessionRecordImportReport
+): void {
+  const { kind, ...fields } = report
+  logger.warn('importing the chat records file did not complete', {
+    scope: 'legacy-record-import',
+    outcome: kind,
+    ...fields
+  })
+}
diff --git a/src/main/runtime/structured-agent-session-lifecycle-delivery.ts b/src/main/runtime/structured-agent-session-lifecycle-delivery.ts
index 961c4d50aa8..ccf026de359 100644
--- a/src/main/runtime/structured-agent-session-lifecycle-delivery.ts
+++ b/src/main/runtime/structured-agent-session-lifecycle-delivery.ts
@@ -7,10 +7,11 @@
 // serialized step, and is tracked here so the same drain still waits for it.
 
 import type { StructuredAgentSessionLifecycleEvent } from '../native-chat/agent-session-wire/structured-agent-session-adapter'
+import type { StructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 
 export function createStructuredAgentSessionLifecycleDelivery(input: {
   handle: (event: StructuredAgentSessionLifecycleEvent) => Promise<void> | undefined
-  onError?: (input: { scope: string; error: unknown }) => void
+  logger: StructuredAgentSessionLogger
   /** Exits the adapter has observed but not yet published. */
   drainObservedExits: () => Promise<void>
 }): {
@@ -24,8 +25,11 @@ export function createStructuredAgentSessionLifecycleDelivery(input: {
     try {
       await input.handle(event)
     } catch (error) {
-      const scope = event.type === 'started' ? 'started' : 'exit'
-      input.onError?.({ scope: `structured-agent-session-${scope}:${event.sessionId}`, error })
+      input.logger.warn(`delivering a provider ${event.type} event to the host failed`, {
+        scope: event.type === 'started' ? 'lifecycle-started' : 'lifecycle-exit',
+        sessionId: event.sessionId,
+        error
+      })
     }
   }
   return {
diff --git a/src/main/runtime/structured-agent-session-record-import-install.test.ts b/src/main/runtime/structured-agent-session-record-import-install.test.ts
index 551fab477c4..dd76d01e6c6 100644
--- a/src/main/runtime/structured-agent-session-record-import-install.test.ts
+++ b/src/main/runtime/structured-agent-session-record-import-install.test.ts
@@ -17,6 +17,7 @@ import {
   ensureStructuredAgentSessionHost,
   stopStructuredAgentSessionRuntime
 } from './structured-agent-session-runtime'
+import { recordingStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 const NOW = 1_800_000_000_000
 const IMPORTED = 'session-alpha-1'
@@ -60,7 +61,7 @@ function databaseVersion(): number {
 }
 
 /** The runtime at startup, rooted at `root`, with its PTY daemon stubbed. */
-function startupRuntime(onError: (input: { scope: string; error: unknown }) => void) {
+function startupRuntime(log: ReturnType<typeof recordingStructuredAgentSessionLogger>) {
   const runtime = new OrcaRuntimeService()
   // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: these are the runtime's own protected members; the test roots the host at `root` and stubs the PTY daemon.
   const internal = runtime as unknown as {
@@ -72,13 +73,13 @@ function startupRuntime(onError: (input: { scope: string; error: unknown }) => v
   internal.hasPersistedStructuredAgentSessionStore = () => true
   internal.ensureStructuredAgentSessionHost = () =>
     ensureStructuredAgentSessionHost({
+      logger: log.logger,
       stateDirectory: root,
       hostId: 'local',
       claimKeyId: 'key-1',
       resolveWorkspacePath: async () => root,
       resolveEnvironment: async () => ({}),
-      resolveClaudeAuthPolicy: () => ({ stripAuthEnv: true }),
-      onError
+      resolveClaudeAuthPolicy: () => ({ stripAuthEnv: true })
     })
   internal.refreshMobileSessionPtyRecords = async () => new Set<string>()
   return {
@@ -88,11 +89,11 @@ function startupRuntime(onError: (input: { scope: string; error: unknown }) => v
   }
 }
 
-function importReports(onError: ReturnType<typeof vi.fn>): unknown[] {
-  return onError.mock.calls
-    .map(([input]) => input)
-    .filter((input) => input.scope === 'structured-agent-session-record-import')
-    .map((input) => input.error)
+/** Each import report the install logged, its kind as the entry's outcome. */
+function importReports(log: ReturnType<typeof recordingStructuredAgentSessionLogger>): unknown[] {
+  return log.entries
+    .filter((entry) => entry.fields.scope === 'legacy-record-import')
+    .map(({ fields: { scope: _scope, outcome, ...rest } }) => ({ kind: outcome, ...rest }))
 }
 
 // A read that can clear: the file's own permissions, as a locked-down or mid-restore profile has.
@@ -101,13 +102,13 @@ it.skipIf(process.platform === 'win32' || process.getuid?.() === 0)(
   async () => {
     await writeLegacy(legacyFile())
     await chmod(legacyAgentSessionStorePath(root), 0o000)
-    const onError = vi.fn()
-    const first = startupRuntime(onError)
+    const log = recordingStructuredAgentSessionLogger()
+    const first = startupRuntime(log)
 
     await first.runtime.restoreStructuredAgentSessionTabs()
     const host = await first.host()
 
-    expect(importReports(onError)).toEqual([
+    expect(importReports(log)).toEqual([
       {
         kind: 'unavailable',
         error: expect.objectContaining({ message: 'agent_session_store_corrupt' })
@@ -142,7 +143,7 @@ it.skipIf(process.platform === 'win32' || process.getuid?.() === 0)(
     await stopStructuredAgentSessionRuntime()
 
     await chmod(legacyAgentSessionStorePath(root), 0o600)
-    const second = startupRuntime(vi.fn())
+    const second = startupRuntime(recordingStructuredAgentSessionLogger())
     await second.runtime.restoreStructuredAgentSessionTabs()
     const relaunched = await second.host()
 
@@ -156,12 +157,12 @@ it.skipIf(process.platform === 'win32' || process.getuid?.() === 0)(
 
 it('installs over a file no read will make usable, reports it once, and leaves it untouched', async () => {
   await writeLegacy('{ truncated')
-  const onError = vi.fn()
-  const { runtime, host } = startupRuntime(onError)
+  const log = recordingStructuredAgentSessionLogger()
+  const { runtime, host } = startupRuntime(log)
 
   await expect(runtime.prepareStructuredAgentSessionStartupRestoration()).resolves.toBeUndefined()
 
-  expect(importReports(onError)).toEqual([
+  expect(importReports(log)).toEqual([
     { kind: 'unusable', error: expect.objectContaining({ message: 'agent_session_store_corrupt' }) }
   ])
   expect((await host()).legacyRecordImportOwed()).toBe(false)
diff --git a/src/main/runtime/structured-agent-session-runtime-exit.test.ts b/src/main/runtime/structured-agent-session-runtime-exit.test.ts
index 3da0c6f203d..2727b2389f2 100644
--- a/src/main/runtime/structured-agent-session-runtime-exit.test.ts
+++ b/src/main/runtime/structured-agent-session-runtime-exit.test.ts
@@ -17,6 +17,7 @@ import {
   ensureStructuredAgentSessionHost,
   stopStructuredAgentSessionRuntime
 } from './structured-agent-session-runtime'
+import { createStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 
 describe('structured session runtime provider-exit wiring', () => {
   let root: string | null = null
@@ -80,6 +81,7 @@ describe('structured session runtime provider-exit wiring', () => {
       return connection
     }) as typeof openCodexAppServerConnection
     const host = await ensureStructuredAgentSessionHost({
+      logger: createStructuredAgentSessionLogger(),
       stateDirectory: root,
       hostId: 'local',
       claimKeyId: 'key-1',
@@ -184,6 +186,7 @@ describe('structured session runtime provider-exit wiring', () => {
       return connection
     }) as typeof openCodexAppServerConnection
     const host = await ensureStructuredAgentSessionHost({
+      logger: createStructuredAgentSessionLogger(),
       stateDirectory: root,
       hostId: 'local',
       claimKeyId: 'key-1',
@@ -214,6 +217,7 @@ describe('structured session runtime provider-exit wiring', () => {
     })
 
     const restarted = await ensureStructuredAgentSessionHost({
+      logger: createStructuredAgentSessionLogger(),
       stateDirectory: root,
       hostId: 'local',
       claimKeyId: 'key-1',
@@ -288,6 +292,7 @@ describe('structured session runtime provider-exit wiring', () => {
       return connection
     }) as typeof openCodexAppServerConnection
     const host = await ensureStructuredAgentSessionHost({
+      logger: createStructuredAgentSessionLogger(),
       stateDirectory: root,
       hostId: 'local',
       claimKeyId: 'key-1',
@@ -394,6 +399,7 @@ describe('structured session runtime provider-exit wiring', () => {
       return connection
     }
     const host = await ensureStructuredAgentSessionHost({
+      logger: createStructuredAgentSessionLogger(),
       stateDirectory: root,
       hostId: 'local',
       claimKeyId: 'key-1',
diff --git a/src/main/runtime/structured-agent-session-runtime.test.ts b/src/main/runtime/structured-agent-session-runtime.test.ts
index e1d37c452a1..f572e890983 100644
--- a/src/main/runtime/structured-agent-session-runtime.test.ts
+++ b/src/main/runtime/structured-agent-session-runtime.test.ts
@@ -28,6 +28,7 @@ import {
   hasPersistedStructuredAgentSessionStore,
   stopStructuredAgentSessionRuntime
 } from './structured-agent-session-runtime'
+import { createStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 
 const HOST_ID = 'local'
 
@@ -258,6 +259,7 @@ describe('structured agent-session runtime install', () => {
   it('holds stop until the model catalog has written its coalesced save', async () => {
     stateDirectory = await mkdtemp(join(tmpdir(), 'orca-structured-runtime-'))
     await ensureStructuredAgentSessionHost({
+      logger: createStructuredAgentSessionLogger(),
       stateDirectory,
       hostId: HOST_ID,
       claimKeyId: 'key-1',
@@ -297,6 +299,7 @@ describe('structured agent-session runtime install', () => {
     __setWindowsProcessTreeLoaderForTests(() => null)
     try {
       const host = await ensureStructuredAgentSessionHost({
+        logger: createStructuredAgentSessionLogger(),
         stateDirectory,
         hostId: HOST_ID,
         claimKeyId: 'key-1',
diff --git a/src/main/runtime/structured-agent-session-runtime.ts b/src/main/runtime/structured-agent-session-runtime.ts
index aecf034b370..3785fdeaf5c 100644
--- a/src/main/runtime/structured-agent-session-runtime.ts
+++ b/src/main/runtime/structured-agent-session-runtime.ts
@@ -13,7 +13,6 @@
 import type { PermissionMode } from '@anthropic-ai/claude-agent-sdk'
 import { existsSync } from 'node:fs'
 import type { AgentSessionRecord } from '../../shared/agent-session-record'
-import { DISPATCH_DOUBT_PROVIDER_IDLE } from '../native-chat/agent-session-journal/journal-dispatch-doubt-reasons'
 import type { AgentSessionResumeTrigger } from '../../shared/agent-session-resume-marker'
 import {
   structuredAgentSessionTeardownTrigger,
@@ -53,7 +52,12 @@ import { createStructuredAgentEnvironmentResolvers } from './structured-agent-sh
 import type { ClaudeStructuredAuthPolicy } from '../claude-accounts/claude-structured-auth-policy'
 import { createStructuredClaudeRuntimeAdapter } from './structured-claude-runtime-adapter'
 import { createStructuredAgentSessionLifecycleDelivery } from './structured-agent-session-lifecycle-delivery'
+import { createStructuredAgentSessionDispatchFollowUps } from './structured-agent-session-dispatch-followups'
 import { agentModelCatalogStore } from '../native-chat/agent-model-catalog/agent-model-catalog-store'
+import {
+  neverThrowingStructuredAgentSessionLogger,
+  type StructuredAgentSessionLogger
+} from '../native-chat/agent-session-wire/structured-agent-session-logger'
 import {
   modelCatalogHostDeps,
   type RuntimeAgentAccountHomeResolver
@@ -113,7 +117,9 @@ export type StructuredAgentSessionRuntimeDeps = {
   /** Which login-shell variables Codex and Claude children inherit; absent inherits all. */
   resolveShellEnvironmentPolicy?: () => NativeChatShellEnvironmentPolicy
   resolveCodexOverrides?: () => NodeJS.ProcessEnv
-  onError?: (input: { scope: string; error: unknown }) => void
+  /** Where every failure the runtime and its host carry on past is reported. Required, so no path
+   *  can drop one: the desktop and headless hosts both pass the trace-file logger. */
+  logger: StructuredAgentSessionLogger
   /** Every structured-session status projection, for host-side reactions such as the first-work
    *  workspace rename that CLI agents get from their hooks. */
   onSessionStatusChanged?: StructuredAgentSessionHostDeps['onSessionStatusChanged']
@@ -132,6 +138,11 @@ let installing: Promise<InstalledRuntime> | null = null
 export const CLAUDE_STRUCTURED_AUTH_POLICY_REQUIRED =
   'structured agent-session host requires a Claude auth policy resolver'
 
+/** Thrown when the host is installed without a logger: every failure it carries on past would
+ *  otherwise reach nobody. */
+export const STRUCTURED_AGENT_SESSION_LOGGER_REQUIRED =
+  'structured agent-session host requires a logger'
+
 /**
  * Runtimes whose teardown did not finish. `installing` is cleared regardless so
  * nothing new attaches, but dropping the runtime as well would strand every
@@ -206,16 +217,18 @@ async function install(deps: StructuredAgentSessionRuntimeDeps): Promise<Install
   if (typeof deps.resolveClaudeAuthPolicy !== 'function') {
     throw new Error(CLAUDE_STRUCTURED_AUTH_POLICY_REQUIRED)
   }
+  const declared: Partial<StructuredAgentSessionLogger> | undefined = deps.logger
+  if (typeof declared?.warn !== 'function' || typeof declared.error !== 'function') {
+    throw new Error(STRUCTURED_AGENT_SESSION_LOGGER_REQUIRED)
+  }
+  const logger = neverThrowingStructuredAgentSessionLogger(deps.logger)
   const journalDatabase = await openStructuredAgentSessionJournalDatabase({
     stateDirectory: deps.stateDirectory,
     hostId: deps.hostId,
-    onLegacyRecordImportReport: (report) =>
-      deps.onError
-        ? deps.onError({ scope: 'structured-agent-session-record-import', error: report })
-        : console.warn('[structured-agent-session] importing the chat records file', report)
+    logger
   })
   try {
-    return await installOnJournal(deps, journalDatabase)
+    return await installOnJournal({ ...deps, logger }, journalDatabase)
   } catch (error) {
     // Nothing else holds the connection yet, and the next install opens its own.
     journalDatabase.close()
@@ -233,35 +246,13 @@ async function installOnJournal(
   let host: StructuredAgentSessionHost | null = null
   const lifecycle = createStructuredAgentSessionLifecycleDelivery({
     handle: (event) => host?.handleAdapterEvent(event),
-    ...(deps.onError ? { onError: deps.onError } : {}),
+    logger: deps.logger,
     // Claude publishes an observed exit only after its close ladder and transcript write; Codex
     // publishes inside its own exit callback and needs nothing.
     drainObservedExits: () => claude.drainObservedExits()
   })
-  const onDispatchSettledLate = (
-    settlement: Parameters<StructuredAgentSessionHost['settleLateDispatch']>[0]
-  ): void => {
-    void host?.settleLateDispatch(settlement).catch((error) =>
-      deps.onError?.({
-        scope: `structured-agent-session-late-settlement:${settlement.sessionId}`,
-        error
-      })
-    )
-  }
-  // The provider going idle is what re-derives a doubted send; a late echo still accepts it.
-  const releaseUnansweredDispatches = ({ sessionId }: { sessionId: string }): void => {
-    void host
-      ?.releaseUnansweredDispatches({
-        sessionId,
-        reason: DISPATCH_DOUBT_PROVIDER_IDLE
-      })
-      .catch((error) =>
-        deps.onError?.({
-          scope: `structured-agent-session-unanswered-dispatch:${sessionId}`,
-          error
-        })
-      )
-  }
+  const { onDispatchSettledLate, releaseUnansweredDispatches } =
+    createStructuredAgentSessionDispatchFollowUps({ host: () => host, logger: deps.logger })
   const codex = new CodexStructuredSessionAdapter({
     resolveLaunch: createCodexStructuredLaunchResolver({
       store,
@@ -327,12 +318,7 @@ async function installOnJournal(
             await deps.resolveLaunchArgs!(provider)
         }
       : {}),
-    onEventSinkError: ({ sessionId, error }) =>
-      deps.onError?.({ scope: `structured-agent-session-journal:${sessionId}`, error }),
-    onLeaseReconcileFailure: (error) =>
-      deps.onError
-        ? deps.onError({ scope: 'structured-agent-session-lease-reconcile', error })
-        : console.warn('[structured-agent-session] reconciling chat leases failed', error),
+    logger: deps.logger,
     ...(deps.onSessionStatusChanged ? { onSessionStatusChanged: deps.onSessionStatusChanged } : {}),
     ...(deps.statusSink ? { statusSink: deps.statusSink } : {}),
     ...(deps.hasOpenDispatch ? { hasOpenDispatch: deps.hasOpenDispatch } : {}),
diff --git a/src/main/runtime/structured-agent-session-spawn-token-descendants.test.ts b/src/main/runtime/structured-agent-session-spawn-token-descendants.test.ts
index d86c54282c1..aee47ab15ba 100644
--- a/src/main/runtime/structured-agent-session-spawn-token-descendants.test.ts
+++ b/src/main/runtime/structured-agent-session-spawn-token-descendants.test.ts
@@ -17,6 +17,7 @@ import {
   ensureStructuredAgentSessionHost,
   stopStructuredAgentSessionRuntime
 } from './structured-agent-session-runtime'
+import { createStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 
 /** pid -> the NUL-separated environment block `/proc/<pid>/environ` serves. */
 const fakeProc = vi.hoisted(() => ({ environs: new Map<number, string>() }))
@@ -135,6 +136,7 @@ describe('a process that inherited a spawn token', () => {
     const kill = vi.spyOn(process, 'kill').mockImplementation(() => true)
 
     const host = await ensureStructuredAgentSessionHost({
+      logger: createStructuredAgentSessionLogger(),
       stateDirectory,
       hostId: HOST_ID,
       claimKeyId: 'key-1',
diff --git a/src/main/runtime/structured-agent-session-startup-reconcile.test.ts b/src/main/runtime/structured-agent-session-startup-reconcile.test.ts
index 32b30a5dc77..43d457790e3 100644
--- a/src/main/runtime/structured-agent-session-startup-reconcile.test.ts
+++ b/src/main/runtime/structured-agent-session-startup-reconcile.test.ts
@@ -21,6 +21,7 @@ import {
   ensureStructuredAgentSessionHost,
   stopStructuredAgentSessionRuntime
 } from './structured-agent-session-runtime'
+import { recordingStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 const writes = vi.hoisted(() => ({ failing: false }))
 
@@ -62,7 +63,7 @@ async function seedChat(options: { newer?: boolean } = {}) {
   return { path: journalDatabasePath(root), sessionId: record.sessionId }
 }
 
-function startupRuntime(onError?: (input: { scope: string; error: unknown }) => void) {
+function startupRuntime(log = recordingStructuredAgentSessionLogger()) {
   const runtime = new OrcaRuntimeService()
   // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: these are the runtime's own protected members; the test roots the host at `root` and stubs the PTY daemon.
   const internal = runtime as unknown as {
@@ -73,13 +74,13 @@ function startupRuntime(onError?: (input: { scope: string; error: unknown }) =>
   internal.hasPersistedStructuredAgentSessionStore = () => true
   internal.ensureStructuredAgentSessionHost = () =>
     ensureStructuredAgentSessionHost({
+      logger: log.logger,
       stateDirectory: root,
       hostId: 'local',
       claimKeyId: 'key-1',
       resolveWorkspacePath: async () => root,
       resolveEnvironment: async () => ({}),
-      resolveClaudeAuthPolicy: () => ({ stripAuthEnv: true }),
-      ...(onError ? { onError } : {})
+      resolveClaudeAuthPolicy: () => ({ stripAuthEnv: true })
     })
   internal.refreshMobileSessionPtyRecords = async () => new Set<string>()
   return runtime
@@ -88,13 +89,13 @@ function startupRuntime(onError?: (input: { scope: string; error: unknown }) =>
 it('finishes startup over records a newer Orca wrote, reads them, and writes nothing', async () => {
   const { path, sessionId } = await seedChat({ newer: true })
   const bytes = await readFile(path)
-  const onError = vi.fn()
-  const runtime = startupRuntime(onError)
+  const log = recordingStructuredAgentSessionLogger()
+  const runtime = startupRuntime(log)
 
   // What the renderer's startup awaits through `app:prepareTerminalStartupRestoration`.
   await expect(runtime.prepareStructuredAgentSessionStartupRestoration()).resolves.toBeUndefined()
 
-  expect(onError).not.toHaveBeenCalled()
+  expect(log.entries).toEqual([])
   const host = getStructuredAgentSessionHost()
   expect(host?.sessionAgent(sessionId)).toBe('claude')
   // Adjudicated in memory only: the verdict is re-derived at the next start.
@@ -105,45 +106,32 @@ it('finishes startup over records a newer Orca wrote, reads them, and writes not
 
 it('finishes startup when the reconcile cannot write, and reports it', async () => {
   const { sessionId } = await seedChat()
-  const onError = vi.fn()
-  const runtime = startupRuntime(onError)
+  const log = recordingStructuredAgentSessionLogger()
+  const runtime = startupRuntime(log)
   writes.failing = true
 
   await expect(runtime.prepareStructuredAgentSessionStartupRestoration()).resolves.toBeUndefined()
 
-  expect(onError).toHaveBeenCalledOnce()
-  expect(onError).toHaveBeenCalledWith({
-    scope: 'structured-agent-session-lease-reconcile',
-    error: expect.objectContaining({ message: 'disk I/O error' })
-  })
+  expect(log.entries).toEqual([
+    expect.objectContaining({
+      fields: {
+        scope: 'lease-reconcile',
+        error: expect.objectContaining({ message: 'disk I/O error' })
+      }
+    })
+  ])
   expect(getStructuredAgentSessionHost()?.sessionAgent(sessionId)).toBe('claude')
 })
 
-// The desktop installs its host with no error sink, so the failure is logged rather than dropped.
-it('logs the failure when the host has no error sink', async () => {
-  await seedChat()
-  const warn = vi.spyOn(console, 'warn').mockImplementation(() => undefined)
-  writes.failing = true
-
-  await expect(
-    startupRuntime().prepareStructuredAgentSessionStartupRestoration()
-  ).resolves.toBeUndefined()
-
-  expect(warn).toHaveBeenCalledWith(
-    '[structured-agent-session] reconciling chat leases failed',
-    expect.objectContaining({ message: 'disk I/O error' })
-  )
-})
-
 // Closing a chat tab drops it from the restore index, which a newer Orca's records refuse: the
 // close is reported and goes on, since bookkeeping never keeps a tab open.
 it('closes a chat tab over records a newer Orca wrote, reporting the index it cannot write', async () => {
   const { sessionId } = await seedChat({ newer: true })
-  const runtime = startupRuntime(vi.fn())
+  const log = recordingStructuredAgentSessionLogger()
+  const runtime = startupRuntime(log)
   await runtime.prepareStructuredAgentSessionStartupRestoration()
   const host = getStructuredAgentSessionHost()
   const close = vi.spyOn(host!, 'close')
-  const warn = vi.spyOn(console, 'warn').mockImplementation(() => undefined)
   // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: the runtime's own protected close path, reached with the one field it reads.
   const internal = runtime as unknown as {
     closeStructuredAgentSessionTab(tab: { sessionId: string }, cause: 'user-close'): Promise<void>
@@ -153,11 +141,16 @@ it('closes a chat tab over records a newer Orca wrote, reporting the index it ca
     internal.closeStructuredAgentSessionTab({ sessionId }, 'user-close')
   ).resolves.toBeUndefined()
 
-  expect(warn).toHaveBeenCalledWith(
-    '[structured-agent-session] recording a closed chat tab failed',
-    expect.objectContaining({
-      refusal: expect.objectContaining({ details: { reason: 'journalWrittenByNewerOrca' } })
-    })
-  )
+  expect(log.entries).toContainEqual({
+    level: 'warn',
+    message: 'recording a closed chat tab failed',
+    fields: {
+      scope: 'tab-visibility-close',
+      sessionId,
+      error: expect.objectContaining({
+        refusal: expect.objectContaining({ details: { reason: 'journalWrittenByNewerOrca' } })
+      })
+    }
+  })
   expect(close).toHaveBeenCalledWith(sessionId, 'user-close')
 })
diff --git a/src/main/runtime/structured-agent-session-startup-tab-restore.test.ts b/src/main/runtime/structured-agent-session-startup-tab-restore.test.ts
index 84c14b2e23c..ac6df4c4b2b 100644
--- a/src/main/runtime/structured-agent-session-startup-tab-restore.test.ts
+++ b/src/main/runtime/structured-agent-session-startup-tab-restore.test.ts
@@ -35,6 +35,8 @@ import {
   ensureStructuredAgentSessionHost,
   stopStructuredAgentSessionRuntime
 } from './structured-agent-session-runtime'
+import { createStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
+import { recordingStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 // `failing` fails every record write; `grants` lets that many more through, then fails.
 const writes = vi.hoisted(() => ({ failing: false, grants: Infinity, refused: 0 }))
@@ -134,9 +136,9 @@ async function seedProfile(
     })
   )
   const database = await openStructuredAgentSessionJournalDatabase({
+    logger: createStructuredAgentSessionLogger(),
     stateDirectory: root,
-    hostId: 'local',
-    onLegacyRecordImportReport: () => undefined
+    hostId: 'local'
   })
   for (const record of options.history ?? records) {
     const fence = record.lease.runtimeFence
@@ -174,9 +176,9 @@ async function seedChatOpenedWhileOwed(record: AgentSessionRecord, tabId: string
   // A directory where the file belongs: the read fails in a way that can clear.
   await mkdir(legacyAgentSessionStorePath(root), { recursive: true })
   const database = await openStructuredAgentSessionJournalDatabase({
+    logger: createStructuredAgentSessionLogger(),
     stateDirectory: root,
-    hostId: 'local',
-    onLegacyRecordImportReport: () => undefined
+    hostId: 'local'
   })
   database.db
     .prepare('INSERT INTO agent_session_records (session_id, record_json) VALUES (?, ?)')
@@ -190,7 +192,7 @@ async function seedChatOpenedWhileOwed(record: AgentSessionRecord, tabId: string
 }
 
 function startupRuntime(options: { afterInstall?: () => void; profileChats?: string[] } = {}) {
-  const onError = vi.fn()
+  const log = recordingStructuredAgentSessionLogger()
   const runtime = new OrcaRuntimeService()
   // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: these are the runtime's own protected members; the test roots the host at `root`, stubs the PTY daemon and gives it a profile.
   const internal = runtime as unknown as {
@@ -203,13 +205,13 @@ function startupRuntime(options: { afterInstall?: () => void; profileChats?: str
   internal.hasPersistedStructuredAgentSessionStore = () => true
   internal.ensureStructuredAgentSessionHost = async () => {
     const installed = await ensureStructuredAgentSessionHost({
+      logger: log.logger,
       stateDirectory: root,
       hostId: 'local',
       claimKeyId: 'key-1',
       resolveWorkspacePath: async () => root,
       resolveEnvironment: async () => ({}),
-      resolveClaudeAuthPolicy: () => ({ stripAuthEnv: true }),
-      onError
+      resolveClaudeAuthPolicy: () => ({ stripAuthEnv: true })
     })
     options.afterInstall?.()
     return installed
@@ -241,7 +243,7 @@ function startupRuntime(options: { afterInstall?: () => void; profileChats?: str
   }
   return {
     runtime,
-    onError,
+    log,
     published: () => internal.mobileSessionTabsByWorktree.get('workspace-1')?.tabs ?? []
   }
 }
@@ -283,7 +285,7 @@ describe('restoring the chat tabs open at quit', () => {
       const tabWrites = spyOnTabWrites()
       vi.spyOn(console, 'warn').mockImplementation(() => undefined)
       // Writable when the store opens, then failing for good.
-      const { runtime, onError, published } = startupRuntime({
+      const { runtime, log, published } = startupRuntime({
         afterInstall: () => {
           writes.failing = writesFail
         }
@@ -300,13 +302,16 @@ describe('restoring the chat tabs open at quit', () => {
       await expectHistory(CHAT_B)
       // A newer Orca's leases are adjudicated in memory, so nothing fails there.
       if (newer) {
-        expect(onError).not.toHaveBeenCalled()
+        expect(log.entries).toEqual([])
       } else {
-        expect(onError).toHaveBeenCalledOnce()
-        expect(onError).toHaveBeenCalledWith({
-          scope: 'structured-agent-session-lease-reconcile',
-          error: expect.objectContaining({ message: 'disk I/O error' })
-        })
+        expect(log.entries).toEqual([
+          expect.objectContaining({
+            fields: {
+              scope: 'lease-reconcile',
+              error: expect.objectContaining({ message: 'disk I/O error' })
+            }
+          })
+        ])
       }
       expect(tabWrites.visibility).not.toHaveBeenCalled()
       expect(tabWrites.seed).not.toHaveBeenCalled()
@@ -408,8 +413,7 @@ describe('restoring the chat tabs open at quit', () => {
     it('still lists the chats when that write fails, and leaves the index absent', async () => {
       const records = legacyChats()
       await seedProfile(records)
-      const warn = vi.spyOn(console, 'warn').mockImplementation(() => undefined)
-      const { runtime, published } = startupRuntime({ profileChats: [CHAT_A, CHAT_B] })
+      const { runtime, published, log } = startupRuntime({ profileChats: [CHAT_A, CHAT_B] })
       await runtime.prepareStructuredAgentSessionStartupRestoration()
       writes.failing = true
 
@@ -417,13 +421,15 @@ describe('restoring the chat tabs open at quit', () => {
 
       expect(published()).toHaveLength(2)
       await expectHistory(CHAT_A)
-      expect(warn).toHaveBeenCalledWith(
-        '[structured-agent-session] recording restored chat tabs failed',
-        {
+      expect(log.entries).toContainEqual({
+        level: 'warn',
+        message: 'recording restored chat tabs failed',
+        fields: {
+          scope: 'tab-index-seed',
           sessionIds: [CHAT_A, CHAT_B],
           error: expect.objectContaining({ message: 'disk I/O error' })
         }
-      )
+      })
       expect(await tabIndexOnDisk()).toBeUndefined()
     })
   })
diff --git a/src/main/runtime/structured-agent-session-tab-index-seed.ts b/src/main/runtime/structured-agent-session-tab-index-seed.ts
index 188a419f31e..3e2245148a2 100644
--- a/src/main/runtime/structured-agent-session-tab-index-seed.ts
+++ b/src/main/runtime/structured-agent-session-tab-index-seed.ts
@@ -11,7 +11,7 @@ type TabIndexHost = Pick<
 
 /** Best-effort: the tabs publish either way, and an index still absent is seeded again next launch. */
 export async function seedStructuredAgentSessionTabIndex(
-  host: Partial<TabIndexHost> | null | undefined,
+  host: (Partial<TabIndexHost> & Pick<StructuredAgentSessionHost, 'deps'>) | null | undefined,
   targets: readonly string[],
   restored: readonly string[]
 ): Promise<void> {
@@ -27,7 +27,8 @@ export async function seedStructuredAgentSessionTabIndex(
   )
   if (unlisted.length > 0) {
     await host.showSessionTabs(unlisted).catch((error: unknown) =>
-      console.warn('[structured-agent-session] recording restored chat tabs failed', {
+      host.deps.logger.warn('recording restored chat tabs failed', {
+        scope: 'tab-index-seed',
         sessionIds: unlisted,
         error
       })
diff --git a/src/main/runtime/structured-chat-coordinator-mail.test.ts b/src/main/runtime/structured-chat-coordinator-mail.test.ts
index 7b2f0d2fe85..c9c3b8448ad 100644
--- a/src/main/runtime/structured-chat-coordinator-mail.test.ts
+++ b/src/main/runtime/structured-chat-coordinator-mail.test.ts
@@ -42,6 +42,7 @@ import {
   resetProviderFaults,
   type FakeConnection
 } from './structured-chat-coordinator-fake-codex-fixture'
+import { createStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 
 const COORDINATOR = '4a1f6c2e-8b3d-4e7a-9c15-0d2b6e8f1a37'
 const PEER_CHAT = '7e3b9d15-2c4a-4f86-a0b1-5c9e2d7f3b64'
@@ -255,6 +256,7 @@ beforeEach(async () => {
   db = new OrchestrationDb(':memory:')
   runtime = startRuntime()
   host = await ensureStructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     stateDirectory: root,
     hostId: 'local',
     claimKeyId: 'key-1',
diff --git a/src/main/runtime/structured-child-records-switch.test.ts b/src/main/runtime/structured-child-records-switch.test.ts
index ea3559e3059..eaf5644164f 100644
--- a/src/main/runtime/structured-child-records-switch.test.ts
+++ b/src/main/runtime/structured-child-records-switch.test.ts
@@ -33,6 +33,7 @@ import {
   ensureStructuredAgentSessionHost,
   stopStructuredAgentSessionRuntime
 } from './structured-agent-session-runtime'
+import { createStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 
 vi.mock('../telemetry/client', () => ({ track: vi.fn() }))
 vi.mock('../telemetry/cohort-classifier', () => ({ getCohortAtEmit: vi.fn() }))
@@ -117,6 +118,7 @@ describe('the chat strip and the session list read the same host child records',
       readChildWork: (subject) => server.getStructuredChildWorkViews(subject)
     }
     const host = await ensureStructuredAgentSessionHost({
+      logger: createStructuredAgentSessionLogger(),
       stateDirectory: root,
       hostId: 'local',
       claimKeyId: 'key-1',
diff --git a/src/main/runtime/structured-claude-pending-rewind.test.ts b/src/main/runtime/structured-claude-pending-rewind.test.ts
index c521ef8b6d9..47fa6d20100 100644
--- a/src/main/runtime/structured-claude-pending-rewind.test.ts
+++ b/src/main/runtime/structured-claude-pending-rewind.test.ts
@@ -24,6 +24,7 @@ import type { AgentSessionRecordStore } from './agent-session-record-store'
 import { openTestAgentSessionRecordStore } from './agent-session-record-store-test-harness'
 import { createStructuredClaudeRuntimeAdapter } from './structured-claude-runtime-adapter'
 import { openTestJournalHostDatabase } from '../native-chat/agent-session-journal/journal-host-database-test-support'
+import { recordingStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 const caller = { callerKey: 'desktop' }
 const PROVIDER_SESSION_ID = claudeSessionIdForOrcaSession(HOST_TEST_SESSION)
@@ -37,6 +38,7 @@ let store: AgentSessionRecordStore
 let claude: ReturnType<typeof fakeClaude>
 let adapter: ReturnType<typeof createStructuredClaudeRuntimeAdapter>
 let host: StructuredAgentSessionHost
+let log: ReturnType<typeof recordingStructuredAgentSessionLogger>
 
 function attachParams(fence: number | null) {
   return hostTestAttachParams(fence, {
@@ -118,7 +120,9 @@ beforeEach(async () => {
     readProcessStartTime: async () => HOST_TEST_NOW,
     onLifecycleEvent: () => {}
   })
+  log = recordingStructuredAgentSessionLogger()
   host = new StructuredAgentSessionHost({
+    logger: log.logger,
     store,
     // Only Claude sessions are attached here; the router supplies the production create gate.
     adapter: new StructuredAgentSessionAdapterRouter({ claude: adapter, codex: adapter }, () =>
@@ -173,7 +177,6 @@ describe('Claude rewind is unsupported', () => {
   )
 
   it('still attaches when settling the pending rewind fails, and logs it', async () => {
-    const warn = vi.spyOn(console, 'warn').mockImplementation(() => {})
     await seedPendingRewind('prepared')
     const transition = store.transitionHandoff.bind(store)
     vi.spyOn(store, 'transitionHandoff').mockImplementation((sessionId, apply) =>
@@ -189,9 +192,14 @@ describe('Claude rewind is unsupported', () => {
     await reattach()
 
     expect(store.getRecord(HOST_TEST_SESSION)?.rewind?.phase).toBe('prepared')
-    expect(warn).toHaveBeenCalledWith(
-      '[structured-rewind] pending Claude rewind was not settled:',
-      expect.objectContaining({ sessionId: HOST_TEST_SESSION, error: expect.any(Error) })
+    expect(log.entries).toContainEqual(
+      expect.objectContaining({
+        fields: expect.objectContaining({
+          scope: 'rewind-unsupported-settlement',
+          sessionId: HOST_TEST_SESSION,
+          error: expect.any(Error)
+        })
+      })
     )
   })
 })
diff --git a/src/main/runtime/structured-claude-scripted-runtime-test-support.ts b/src/main/runtime/structured-claude-scripted-runtime-test-support.ts
index 07de5e58761..7a69cbe9c86 100644
--- a/src/main/runtime/structured-claude-scripted-runtime-test-support.ts
+++ b/src/main/runtime/structured-claude-scripted-runtime-test-support.ts
@@ -20,6 +20,7 @@ import {
   ensureStructuredAgentSessionHost,
   stopStructuredAgentSessionRuntime
 } from './structured-agent-session-runtime'
+import { createStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 
 /** The error a real CLI's exit reaches the adapter as: Orca's message, the stderr as a log detail. */
 export function scriptedClaudeExitError(diagnostic: string): Error {
@@ -223,6 +224,7 @@ export function createScriptedClaudeRuntime(sessionIds: readonly string[]) {
       await mkdir(join(root, 'claude-home'), { recursive: true })
       const directory = root
       return ensureStructuredAgentSessionHost({
+        logger: createStructuredAgentSessionLogger(),
         stateDirectory: directory,
         hostId: 'local',
         claimKeyId: 'key-1',
diff --git a/src/main/runtime/structured-codex-child-work-runtime.test.ts b/src/main/runtime/structured-codex-child-work-runtime.test.ts
index d03ab6f1be5..5e0cf36f14d 100644
--- a/src/main/runtime/structured-codex-child-work-runtime.test.ts
+++ b/src/main/runtime/structured-codex-child-work-runtime.test.ts
@@ -19,6 +19,7 @@ import {
   ensureStructuredAgentSessionHost,
   stopStructuredAgentSessionRuntime
 } from './structured-agent-session-runtime'
+import { createStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 
 const THREAD = 'thread-runtime-child-work'
 const CHILD = 'thread-runtime-reviewer'
@@ -70,6 +71,7 @@ describe('structured Codex child work through the production runtime', () => {
       NonNullable<StructuredAgentSessionStatusSink['publishChildWork']>
     >[] = []
     const host = await ensureStructuredAgentSessionHost({
+      logger: createStructuredAgentSessionLogger(),
       stateDirectory: root,
       hostId: 'local',
       claimKeyId: 'key-1',
diff --git a/src/main/runtime/structured-codex-session-rpc-test-harness.ts b/src/main/runtime/structured-codex-session-rpc-test-harness.ts
index 9d6c0ef30fb..81e7d3f1d8c 100644
--- a/src/main/runtime/structured-codex-session-rpc-test-harness.ts
+++ b/src/main/runtime/structured-codex-session-rpc-test-harness.ts
@@ -28,6 +28,7 @@ import {
   ensureStructuredAgentSessionHost,
   stopStructuredAgentSessionRuntime
 } from './structured-agent-session-runtime'
+import { createStructuredAgentSessionLogger } from '../native-chat/agent-session-wire/structured-agent-session-logger'
 
 export const SESSION = 'session-integration-1'
 export const THREAD = 'thread-integration'
@@ -206,6 +207,7 @@ export async function openStructuredCodexRpcHarness(
     })
   })
   const hostConfig = (): Parameters<typeof ensureStructuredAgentSessionHost>[0] => ({
+    logger: createStructuredAgentSessionLogger(),
     stateDirectory: root,
     hostId: 'local',
     claimKeyId: 'key-1',
diff --git a/src/main/runtime/structured-session-worktree-teardown.ts b/src/main/runtime/structured-session-worktree-teardown.ts
index 3f8ab31b3ec..047b4a21644 100644
--- a/src/main/runtime/structured-session-worktree-teardown.ts
+++ b/src/main/runtime/structured-session-worktree-teardown.ts
@@ -336,12 +336,14 @@ export async function retireStructuredSessionTabsForWorktree(
  * proved after that close had already rolled the hide back.
  */
 async function dropDurableChatTabReference(sessionId: string): Promise<void> {
+  const host = getStructuredAgentSessionHost()
   try {
-    await getStructuredAgentSessionHost()?.setSessionTabVisibility?.(sessionId, false)
+    await host?.setSessionTabVisibility?.(sessionId, false)
   } catch (error) {
-    console.warn(
-      `[worktree-teardown] could not drop the chat tab reference for ${sessionId}`,
+    host?.deps.logger.warn('dropping a removed workspace chat tab reference failed', {
+      scope: 'teardown-tab-drop',
+      sessionId,
       error
-    )
+    })
   }
 }
diff --git a/tests/e2e/codex-child-approval-activity-row.unit.test.ts b/tests/e2e/codex-child-approval-activity-row.unit.test.ts
index c2df9b1f3e3..27f00644ec1 100644
--- a/tests/e2e/codex-child-approval-activity-row.unit.test.ts
+++ b/tests/e2e/codex-child-approval-activity-row.unit.test.ts
@@ -71,6 +71,8 @@ vi.mock('@/runtime/structured-agent-session-client', () => ({
 
 import { StructuredAgentSessionStatusBridge } from '../../src/renderer/src/components/native-chat/StructuredAgentSessionStatusBridge'
 import { resetStructuredAgentSessionStatusFeedsForTests } from '../../src/renderer/src/runtime/structured-agent-session-status-feed'
+import { createStructuredAgentSessionLogger } from '../../src/main/native-chat/agent-session-wire/structured-agent-session-logger'
+import { testEventSinkLogging } from '../../src/main/native-chat/agent-session-wire/structured-agent-session-logger-test-support'
 
 const SESSION = 'codex-child-approval'
 const CODEX_THREAD = 'thread-parent'
@@ -143,6 +145,7 @@ async function openHost() {
     stateDirectory: join(root, SESSION)
   })
   const feed = new StructuredAgentSessionStatusFeed({
+    logger: createStructuredAgentSessionLogger(),
     sessions: new Map([
       [SESSION, indexedStatusFeedSession({ journal, child: { phase: 'ready' } })]
     ]),
@@ -151,7 +154,7 @@ async function openHost() {
   })
   const events: AgentSessionStatusEvent[] = []
   feed.subscribe({ id: 'renderer', emit: (event) => events.push(event) })
-  const deferred = createDeferredStructuredAgentSessionEventSink()
+  const deferred = createDeferredStructuredAgentSessionEventSink(testEventSinkLogging())
   const publish = (): void => feed.publish(SESSION, journal)
   deferred.bind({ journal, fence: 1, publish })
   const prompts: string[] = []
diff --git a/tests/e2e/cross-version-wire/cross-version-agent-session-wire.unit.test.ts b/tests/e2e/cross-version-wire/cross-version-agent-session-wire.unit.test.ts
index 4aaa02037ec..4969357ba87 100644
--- a/tests/e2e/cross-version-wire/cross-version-agent-session-wire.unit.test.ts
+++ b/tests/e2e/cross-version-wire/cross-version-agent-session-wire.unit.test.ts
@@ -62,6 +62,7 @@ import {
   type RpcReply
 } from './versioned-agent-session-wire'
 import { openTestJournalHostDatabase } from '../../../src/main/native-chat/agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from '../../../src/main/native-chat/agent-session-wire/structured-agent-session-logger'
 
 // Why: a cold CI run extracts the baseline checkout before the first pairing.
 const SUITE_TIMEOUT_MS = 180_000
@@ -475,6 +476,7 @@ describe('cross-version structured agent sessions', () => {
       root = await mkdtemp(join(tmpdir(), 'orca-cross-version-ai-vault-'))
       store = await openTestAgentSessionRecordStore(root)
       const host = new StructuredAgentSessionHost({
+        logger: createStructuredAgentSessionLogger(),
         store,
         adapter: {
           acquire: async ({ fence }) => ({
@@ -701,6 +703,7 @@ describe('cross-version structured agent sessions', () => {
     async function bootHost(generation: string): Promise<StructuredAgentSessionHost> {
       store = await openTestAgentSessionRecordStore(root)
       const host = new StructuredAgentSessionHost({
+        logger: createStructuredAgentSessionLogger(),
         store,
         adapter: adapter(),
         journalDatabase: openTestJournalHostDatabase(root),
diff --git a/tests/e2e/structured-agent-session-read-owner.unit.test.ts b/tests/e2e/structured-agent-session-read-owner.unit.test.ts
index dafa6e8089d..b7734f2759d 100644
--- a/tests/e2e/structured-agent-session-read-owner.unit.test.ts
+++ b/tests/e2e/structured-agent-session-read-owner.unit.test.ts
@@ -32,6 +32,7 @@ import {
   getStructuredAgentSessionReadOwner,
   resetStructuredAgentSessionReadOwnersForTests
 } from '../../src/renderer/src/components/native-chat/structured-agent-session-read-owner'
+import { createStructuredAgentSessionLogger } from '../../src/main/native-chat/agent-session-wire/structured-agent-session-logger'
 
 const SESSION = 'cursor-body-regression'
 const target = { kind: 'local' } as const
@@ -125,6 +126,7 @@ describe('structured session cursor/body regression', () => {
       const { journal, appendOutput, accept } = await fixture()
       let hostSummary: AgentSessionStatusSummary | undefined
       const feed = new StructuredAgentSessionStatusFeed({
+        logger: createStructuredAgentSessionLogger(),
         sessions: new Map([
           [
             SESSION,
diff --git a/tests/e2e/structured-chat-owner-status-activation.unit.test.ts b/tests/e2e/structured-chat-owner-status-activation.unit.test.ts
index e656b320b62..a5827937358 100644
--- a/tests/e2e/structured-chat-owner-status-activation.unit.test.ts
+++ b/tests/e2e/structured-chat-owner-status-activation.unit.test.ts
@@ -25,6 +25,7 @@ import { runWorktreeAgentActivationGate } from '../../src/renderer/src/lib/workt
 import { readWorktreeStructuredActivationInventory } from '../../src/renderer/src/lib/worktree-agent-structured-inventory'
 import type { RuntimeMobileSessionTabsResult } from '../../src/shared/runtime-types'
 import { openTestJournalHostDatabase } from '../../src/main/native-chat/agent-session-journal/journal-host-database-test-support'
+import { createStructuredAgentSessionLogger } from '../../src/main/native-chat/agent-session-wire/structured-agent-session-logger'
 
 const WORKTREE = 'repo-1::/workspace/repo'
 
@@ -36,6 +37,7 @@ let closeSession: Mock<NonNullable<StructuredAgentSessionAdapter['closeSession']
 
 function openHost(): void {
   host = new StructuredAgentSessionHost({
+    logger: createStructuredAgentSessionLogger(),
     store,
     adapter: {
       acquire: async ({ fence, spawnToken }) => ({