From 3e950ca049f65091aefd8e8961ad132517649641 Mon Sep 17 00:00:00 2001
From: Neil <4138956+nwparker@users.noreply.github.com>
Date: Sun, 25 Oct 2026 02:45:52 -0700
Subject: [PATCH] refactor(native-chat): group tool attribution modules
 (#33482)

---
 .github/workflows/performance-contracts.yml   |  4 +-
 config/scripts/ci-shard-timings.json          |  6 +--
 config/scripts/native-chat-fold-benchmark.mjs | 49 +++++++++++++++++--
 .../native-chat-tool-pairing-benchmark.mjs    | 30 ++++++++++--
 config/vitest.performance.config.ts           |  4 +-
 ...tMessage.tool-result-availability.test.tsx |  2 +-
 .../src/session/MobileNativeChatMessage.tsx   |  2 +-
 .../src/session/MobileNativeChatToolRun.tsx   |  2 +-
 .../session/mobile-native-chat-blocks.test.ts |  3 +-
 .../mobile-native-chat-reading-place.test.tsx |  2 +-
 .../session/mobile-native-chat-render-data.ts |  2 +-
 .../mobile-native-chat-run-descriptors.ts     |  2 +-
 ...bile-native-chat-scroll-ownership.test.tsx |  2 +-
 ...e-chat-session-tool-result-paging.test.tsx |  2 +-
 ...ab-call-rows-on-positional-clients.test.ts |  4 +-
 ...journal-legacy-import-tool-pairing.test.ts |  3 +-
 .../transcript-tool-result-identity.test.ts   |  3 +-
 ...transcript-window-tool-attribution.test.ts |  3 +-
 .../structured-worker-journal-archive.test.ts |  3 +-
 .../NativeChatToolRunMemberList.tsx           |  2 +-
 ...ative-chat-message-list-projection.test.ts |  4 +-
 .../native-chat-task-list-state.test.ts       |  2 +-
 .../native-chat-task-list-state.ts            |  2 +-
 .../native-chat/native-chat-tool-fold.test.ts |  5 +-
 .../native-chat/native-chat-tool-fold.ts      |  6 ---
 .../native-chat-turn-diffs.test.ts            |  2 +-
 .../native-chat-work-run-pairing.test.ts      |  3 +-
 src/shared/native-chat-ask-row.ts             |  2 +-
 src/shared/native-chat-edit-cards.ts          |  2 +-
 src/shared/native-chat-row-content.ts         |  2 +-
 src/shared/native-chat-task-list-history.ts   |  2 +-
 .../native-chat-transcript-contracts.test.ts  |  8 +--
 .../native-chat-transcript-projection.ts      |  2 +-
 src/shared/native-chat-work-run.ts            |  2 +-
 .../tools}/native-chat-folded-tool-results.ts |  2 +-
 ...e-chat-tool-attribution-allocation.test.ts |  2 +-
 .../native-chat-tool-fold-attribution.spec.ts |  5 +-
 .../tools}/native-chat-tool-fold.ts           | 10 ++--
 .../native-chat-tool-pair-limit.spec.ts       |  4 +-
 ...tive-chat-tool-pairing.performance.test.ts |  4 +-
 .../tools}/native-chat-tool-pairing.spec.ts   |  2 +-
 .../tools}/native-chat-tool-pairing.ts        |  4 +-
 .../tools}/native-chat-tool-pairs.ts          |  2 +-
 .../native-chat-tool-result-orphans.spec.ts   | 11 +++--
 ...t-turn-membership-derived-tool-row.test.ts | 14 +++---
 45 files changed, 149 insertions(+), 85 deletions(-)
 delete mode 100644 src/renderer/src/components/native-chat/native-chat-tool-fold.ts
 rename src/shared/{ => native-chat/tools}/native-chat-folded-tool-results.ts (98%)
 rename src/shared/{ => native-chat/tools}/native-chat-tool-attribution-allocation.test.ts (99%)
 rename src/shared/{ => native-chat/tools}/native-chat-tool-fold-attribution.spec.ts (93%)
 rename src/shared/{ => native-chat/tools}/native-chat-tool-fold.ts (94%)
 rename src/shared/{ => native-chat/tools}/native-chat-tool-pair-limit.spec.ts (98%)
 rename src/shared/{ => native-chat/tools}/native-chat-tool-pairing.performance.test.ts (99%)
 rename src/shared/{ => native-chat/tools}/native-chat-tool-pairing.spec.ts (98%)
 rename src/shared/{ => native-chat/tools}/native-chat-tool-pairing.ts (95%)
 rename src/shared/{ => native-chat/tools}/native-chat-tool-pairs.ts (99%)
 rename src/shared/{ => native-chat/tools}/native-chat-tool-result-orphans.spec.ts (94%)
 rename src/shared/{ => native-chat/tools}/native-chat-turn-membership-derived-tool-row.test.ts (94%)

diff --git a/.github/workflows/performance-contracts.yml b/.github/workflows/performance-contracts.yml
index 16b84f2910e..72946ababa2 100644
--- a/.github/workflows/performance-contracts.yml
+++ b/.github/workflows/performance-contracts.yml
@@ -18,8 +18,8 @@ on:
       # without these a rename lands green and only breaks the next nightly.
       - 'src/main/sqlite/sync-database.test.ts'
       - 'src/main/runtime/orchestration/db/row-column-lists.test.ts'
-      - 'src/shared/native-chat-tool-attribution-allocation.test.ts'
-      - 'src/shared/native-chat-tool-pairing.performance.test.ts'
+      - 'src/shared/native-chat/tools/native-chat-tool-attribution-allocation.test.ts'
+      - 'src/shared/native-chat/tools/native-chat-tool-pairing.performance.test.ts'
       - 'src/main/codex-usage/codex-rollout-file-lifetime.test.ts'
       - 'src/main/codex-usage/scanner-incremental-append.test.ts'
       - 'src/main/usage/jsonl-file-reader.test.ts'
diff --git a/config/scripts/ci-shard-timings.json b/config/scripts/ci-shard-timings.json
index f5815cc86ab..719c5b82bd1 100644
--- a/config/scripts/ci-shard-timings.json
+++ b/config/scripts/ci-shard-timings.json
@@ -11585,13 +11585,13 @@
       "src/shared/native-chat-subagent-summary.test.ts": 54,
       "src/shared/native-chat-task-list.test.ts": 45,
       "src/shared/native-chat-tool-activity.test.ts": 49,
-      "src/shared/native-chat-tool-attribution-allocation.test.ts": 112,
+      "src/shared/native-chat/tools/native-chat-tool-attribution-allocation.test.ts": 112,
       "src/shared/native-chat-tool-fold-attribution.test.ts": 39,
       "src/shared/native-chat-tool-icon.test.ts": 83,
       "src/shared/native-chat-tool-identity.test.ts": 64,
       "src/shared/native-chat-tool-line-identity.test.ts": 33,
       "src/shared/native-chat-tool-pair-limit.test.ts": 75,
-      "src/shared/native-chat-tool-pairing.performance.test.ts": 463,
+      "src/shared/native-chat/tools/native-chat-tool-pairing.performance.test.ts": 463,
       "src/shared/native-chat-tool-pairing.test.ts": 41,
       "src/shared/native-chat-tool-preview-prefix.test.ts": 31,
       "src/shared/native-chat-tool-preview-scan.test.ts": 37,
@@ -11604,7 +11604,7 @@
       "src/shared/native-chat-turn-activity.test.ts": 216,
       "src/shared/native-chat-turn-fold.test.ts": 42,
       "src/shared/native-chat-turn-grouping.test.ts": 212,
-      "src/shared/native-chat-turn-membership-derived-tool-row.test.ts": 328,
+      "src/shared/native-chat/tools/native-chat-turn-membership-derived-tool-row.test.ts": 328,
       "src/shared/native-chat-turn-membership.test.ts": 253,
       "src/shared/native-chat-turn-status.test.ts": 69,
       "src/shared/native-chat-unverifiable-turn-status.test.ts": 245,
diff --git a/config/scripts/native-chat-fold-benchmark.mjs b/config/scripts/native-chat-fold-benchmark.mjs
index 6dcc743f305..c1a05cbedfb 100644
--- a/config/scripts/native-chat-fold-benchmark.mjs
+++ b/config/scripts/native-chat-fold-benchmark.mjs
@@ -22,11 +22,11 @@ const refs = {
   published: 'b1e44269d655608447dc535f0a4d7d05c37c80b7',
   current: null
 }
-const entry = `
-  export { foldToolMessages as fold } from './src/shared/native-chat-tool-fold'
+const entry = (ref) => `
+  export { foldToolMessages as fold } from '${ref ? './src/shared/native-chat-tool-fold' : './src/shared/native-chat/tools/native-chat-tool-fold'}'
   import { createNativeChatMessageListProjection } from './src/renderer/src/components/native-chat/native-chat-message-list-projection'
   import { deriveNativeChatRowContent } from './src/shared/native-chat-row-content'
-  import { pairNativeChatToolResults } from './src/shared/native-chat-tool-pairing'
+  import { pairNativeChatToolResults } from '${ref ? './src/shared/native-chat-tool-pairing' : './src/shared/native-chat/tools/native-chat-tool-pairing'}'
   export function createPipeline() {
     const project = createNativeChatMessageListProjection()
     return (messages) => {
@@ -74,10 +74,25 @@ if (process.argv.includes('--memory-control')) {
 }
 
 async function load(ref) {
+  let snapshotFiles
+  if (ref) {
+    const listed = runProcessSync({
+      program: 'git',
+      args: ['ls-tree', '-r', '--name-only', ref, '--', 'src'],
+      cwd: root,
+      env: { ...process.env, ORCA_BACKGROUND_LAUNCH: '1' },
+      timeoutMs: 30_000,
+      maxOutputBytes: 2 * 1024 * 1024
+    })
+    if (listed.code !== 0 || listed.timedOut || listed.outputTruncated) {
+      throw new Error(describeProcessFailure(listed))
+    }
+    snapshotFiles = new Set(listed.stdout.trim().split('\n'))
+  }
   const modules = new Map()
   const built = await build({
     stdin: {
-      contents: entry,
+      contents: entry(ref),
       resolveDir: root,
       sourcefile: 'fold-benchmark-entry.ts',
       loader: 'ts'
@@ -90,6 +105,32 @@ async function load(ref) {
       {
         name: 'exact-chat-source-snapshot',
         setup(builder) {
+          builder.onResolve({ filter: /^\./ }, (args) => {
+            if (!ref) {
+              return undefined
+            }
+            const target = path
+              .relative(root, path.resolve(args.resolveDir, args.path))
+              .split(path.sep)
+              .join('/')
+            if (!target.startsWith('src/')) {
+              return undefined
+            }
+            const candidates = [
+              target,
+              ...['.tsx', '.ts', '.jsx', '.js', '.css', '.json'].map(
+                (extension) => target + extension
+              ),
+              ...['.tsx', '.ts', '.jsx', '.js', '.css', '.json'].map(
+                (extension) => `${target}/index${extension}`
+              )
+            ]
+            const file = candidates.find((candidate) => snapshotFiles.has(candidate))
+            if (!file) {
+              throw new Error(`Missing snapshot source: ${ref}:${target}`)
+            }
+            return { path: path.join(root, file) }
+          })
           builder.onLoad({ filter: /\.[cm]?[jt]sx?$/ }, ({ path: file }) => {
             const relative = path.relative(root, file).split(path.sep).join('/')
             if (!relative.startsWith('src/')) {
diff --git a/config/scripts/native-chat-tool-pairing-benchmark.mjs b/config/scripts/native-chat-tool-pairing-benchmark.mjs
index 5dae5c3f3b3..cc6479bfe61 100644
--- a/config/scripts/native-chat-tool-pairing-benchmark.mjs
+++ b/config/scripts/native-chat-tool-pairing-benchmark.mjs
@@ -9,18 +9,35 @@ import { summarizeBenchmarkSamples } from './benchmark-sample-summary.mjs'
 
 // git show <baseline>:src/shared/native-chat-tool-fold.ts | node config/scripts/native-chat-tool-pairing-benchmark.mjs
 const root = path.resolve(import.meta.dirname, '../..')
-async function load(source) {
+async function load(source, sourcefile = 'src/shared/native-chat-tool-fold.ts') {
   const built = await build({
     stdin: {
       contents: source,
-      sourcefile: 'native-chat-tool-fold.ts',
-      resolveDir: path.join(root, 'src/shared'),
+      sourcefile: path.basename(sourcefile),
+      resolveDir: path.dirname(path.join(root, sourcefile)),
       loader: 'ts'
     },
     bundle: true,
     write: false,
     platform: 'node',
-    format: 'esm'
+    format: 'esm',
+    plugins: [
+      {
+        name: 'relocated-current-pairing-dependencies',
+        setup(builder) {
+          builder.onResolve({ filter: /^\./ }, (args) => {
+            const target = path.resolve(args.resolveDir, args.path)
+            for (const name of ['native-chat-tool-pairs', 'native-chat-folded-tool-results']) {
+              const previous = path.join(root, 'src/shared', name)
+              if (target === previous || target === `${previous}.ts`) {
+                return { path: path.join(root, 'src/shared/native-chat/tools', `${name}.ts`) }
+              }
+            }
+            return undefined
+          })
+        }
+      }
+    ]
   })
   const code = built.outputFiles[0].text
   return {
@@ -32,7 +49,10 @@ async function load(source) {
 
 const loaded = {
   before: await load(readFileSync(0, 'utf8')),
-  after: await load(readFileSync(path.join(root, 'src/shared/native-chat-tool-fold.ts'), 'utf8'))
+  after: await load(
+    readFileSync(path.join(root, 'src/shared/native-chat/tools/native-chat-tool-pairs.ts'), 'utf8'),
+    'src/shared/native-chat/tools/native-chat-tool-pairs.ts'
+  )
 }
 const call = (callId) => ({ type: 'tool-call', name: 'Bash', input: {}, callId })
 const result = (callId) => ({ type: 'tool-result', output: 'done', callId })
diff --git a/config/vitest.performance.config.ts b/config/vitest.performance.config.ts
index 0922d28a917..df26313b144 100644
--- a/config/vitest.performance.config.ts
+++ b/config/vitest.performance.config.ts
@@ -11,8 +11,8 @@ const contracts = [
   'src/renderer/src/components/tab-bar/use-new-tab-agent-menu-host-preferences.test.tsx',
   'src/main/sqlite/sync-database.test.ts',
   'src/main/runtime/orchestration/db/row-column-lists.test.ts',
-  'src/shared/native-chat-tool-attribution-allocation.test.ts',
-  'src/shared/native-chat-tool-pairing.performance.test.ts',
+  'src/shared/native-chat/tools/native-chat-tool-attribution-allocation.test.ts',
+  'src/shared/native-chat/tools/native-chat-tool-pairing.performance.test.ts',
   'src/main/codex-usage/codex-rollout-file-lifetime.test.ts',
   'src/main/codex-usage/scanner-incremental-append.test.ts',
   'src/main/usage/jsonl-file-reader.test.ts',
diff --git a/mobile/src/session/MobileNativeChatMessage.tool-result-availability.test.tsx b/mobile/src/session/MobileNativeChatMessage.tool-result-availability.test.tsx
index c3d7a3b92be..02e4fd96201 100644
--- a/mobile/src/session/MobileNativeChatMessage.tool-result-availability.test.tsx
+++ b/mobile/src/session/MobileNativeChatMessage.tool-result-availability.test.tsx
@@ -6,7 +6,7 @@ import type {
   AgentJournalItemBody,
   AgentJournalRenderItem
 } from '../../../src/shared/agent-session-journal-types'
-import * as toolFold from '../../../src/shared/native-chat-tool-fold'
+import * as toolFold from '../../../src/shared/native-chat/tools/native-chat-tool-pairs'
 import { projectStructuredItemsToNativeChat } from '../../../src/shared/structured-agent-session-projection'
 import { foldMobileNativeChatMessages } from './mobile-native-chat-render-data'
 import { useMobileNativeChatTurnDisclosure } from './use-mobile-native-chat-turn-disclosure'
diff --git a/mobile/src/session/MobileNativeChatMessage.tsx b/mobile/src/session/MobileNativeChatMessage.tsx
index d240eeccb4a..177a47c3189 100644
--- a/mobile/src/session/MobileNativeChatMessage.tsx
+++ b/mobile/src/session/MobileNativeChatMessage.tsx
@@ -2,7 +2,7 @@ import { memo, useCallback, useContext, useLayoutEffect, useMemo, useRef } from
 import { Text, View } from 'react-native'
 import { INLINE_TEXT_SELECTION } from '../components/inline-text-selection'
 import { MobileNativeChatLongPressContent as Content } from './MobileNativeChatLongPressContent'
-import { splitNativeChatBlocks } from '../../../src/shared/native-chat-tool-fold'
+import { splitNativeChatBlocks } from '../../../src/shared/native-chat/tools/native-chat-tool-fold'
 import { selectActiveToolCall } from '../../../src/shared/native-chat-tool-activity'
 import {
   isImageRefBlock,
diff --git a/mobile/src/session/MobileNativeChatToolRun.tsx b/mobile/src/session/MobileNativeChatToolRun.tsx
index cd59281c968..646a7bd5c8f 100644
--- a/mobile/src/session/MobileNativeChatToolRun.tsx
+++ b/mobile/src/session/MobileNativeChatToolRun.tsx
@@ -26,7 +26,7 @@ import {
 } from '../../../src/shared/native-chat-tool-activity'
 import { nativeChatToolRunIconName } from '../../../src/shared/native-chat-tool-icon'
 import { nativeChatToolLineIdentity } from '../../../src/shared/native-chat-tool-line-identity'
-import { pairNativeChatToolResults } from '../../../src/shared/native-chat-tool-pairing'
+import { pairNativeChatToolResults } from '../../../src/shared/native-chat/tools/native-chat-tool-pairing'
 import { nativeChatToolRunOutcome } from '../../../src/shared/native-chat-tool-run-outcome'
 import {
   NATIVE_CHAT_TOOL_RUN_SENTENCE_ENGLISH,
diff --git a/mobile/src/session/mobile-native-chat-blocks.test.ts b/mobile/src/session/mobile-native-chat-blocks.test.ts
index 54fca957d17..5d8fe46e41b 100644
--- a/mobile/src/session/mobile-native-chat-blocks.test.ts
+++ b/mobile/src/session/mobile-native-chat-blocks.test.ts
@@ -1,5 +1,6 @@
 import { describe, expect, it } from 'vitest'
-import { foldToolMessages, pairToolBlocks } from '../../../src/shared/native-chat-tool-fold'
+import { foldToolMessages } from '../../../src/shared/native-chat/tools/native-chat-tool-fold'
+import { pairToolBlocks } from '../../../src/shared/native-chat/tools/native-chat-tool-pairs'
 import type { NativeChatMessage } from '../../../src/shared/native-chat-types'
 
 function msg(
diff --git a/mobile/src/session/mobile-native-chat-reading-place.test.tsx b/mobile/src/session/mobile-native-chat-reading-place.test.tsx
index 9c31b3ad31f..f50f05c6a66 100644
--- a/mobile/src/session/mobile-native-chat-reading-place.test.tsx
+++ b/mobile/src/session/mobile-native-chat-reading-place.test.tsx
@@ -6,7 +6,7 @@ import {
   type ReactTestRendererJSON as Node
 } from 'react-test-renderer'
 import { afterEach, expect, it, vi } from 'vitest'
-import { splitNativeChatBlocks } from '../../../src/shared/native-chat-tool-fold'
+import { splitNativeChatBlocks } from '../../../src/shared/native-chat/tools/native-chat-tool-fold'
 import type { NativeChatBlock, NativeChatMessage } from '../../../src/shared/native-chat-types'
 import { foldMobileNativeChatMessages } from './mobile-native-chat-render-data'
 import {
diff --git a/mobile/src/session/mobile-native-chat-render-data.ts b/mobile/src/session/mobile-native-chat-render-data.ts
index edca0c8fe81..d68f40cca89 100644
--- a/mobile/src/session/mobile-native-chat-render-data.ts
+++ b/mobile/src/session/mobile-native-chat-render-data.ts
@@ -10,7 +10,7 @@ import { isWordlessProviderFrameMessage } from '../../../src/shared/native-chat/
 import {
   foldToolMessages,
   isUndrawnProviderFrameMessage
-} from '../../../src/shared/native-chat-tool-fold'
+} from '../../../src/shared/native-chat/tools/native-chat-tool-fold'
 import { projectNativeChatTaskListFrames } from '../../../src/shared/native-chat-task-list-frames'
 import { foldSubagentItems } from '../../../src/shared/native-chat-subagent-items'
 import { prepareNativeChatMessages } from '../../../src/shared/native-chat-message-preparation'
diff --git a/mobile/src/session/mobile-native-chat-run-descriptors.ts b/mobile/src/session/mobile-native-chat-run-descriptors.ts
index 743cbb6087d..b73a997b661 100644
--- a/mobile/src/session/mobile-native-chat-run-descriptors.ts
+++ b/mobile/src/session/mobile-native-chat-run-descriptors.ts
@@ -1,6 +1,6 @@
 import type { NativeChatMessage } from '../../../src/shared/native-chat-types'
 import type { NativeChatResolvedPrompt } from '../../../src/shared/native-chat-resolution-receipt'
-import { splitNativeChatBlocks } from '../../../src/shared/native-chat-tool-fold'
+import { splitNativeChatBlocks } from '../../../src/shared/native-chat/tools/native-chat-tool-fold'
 import { nativeChatWorkRunEntries } from '../../../src/shared/native-chat-work-run'
 import { nativeChatAskRunBlocks } from '../../../src/shared/native-chat-ask-row'
 import type { MobileNativeChatWorkRuns } from './use-mobile-native-chat-transcript-rows'
diff --git a/mobile/src/session/mobile-native-chat-scroll-ownership.test.tsx b/mobile/src/session/mobile-native-chat-scroll-ownership.test.tsx
index fa2a135ab6f..27bc20eecfc 100644
--- a/mobile/src/session/mobile-native-chat-scroll-ownership.test.tsx
+++ b/mobile/src/session/mobile-native-chat-scroll-ownership.test.tsx
@@ -12,7 +12,7 @@ import {
 import { createRoot, type Root } from 'react-dom/client'
 import { afterEach, expect, it, vi } from 'vitest'
 import type { NativeChatMessage } from '../../../src/shared/native-chat-types'
-import { foldToolMessages } from '../../../src/shared/native-chat-tool-fold'
+import { foldToolMessages } from '../../../src/shared/native-chat/tools/native-chat-tool-fold'
 import { MobileNativeChatMessage } from './MobileNativeChatMessage'
 import { MobileNativeChatScrollRootsBoundary } from './MobileNativeChatScrollRootsBoundary'
 import { MobileNativeChatScrollMotion } from './mobile-native-chat-scroll-motion'
diff --git a/mobile/src/session/use-mobile-native-chat-session-tool-result-paging.test.tsx b/mobile/src/session/use-mobile-native-chat-session-tool-result-paging.test.tsx
index 5392718155d..c561592a031 100644
--- a/mobile/src/session/use-mobile-native-chat-session-tool-result-paging.test.tsx
+++ b/mobile/src/session/use-mobile-native-chat-session-tool-result-paging.test.tsx
@@ -1,7 +1,7 @@
 import { createElement } from 'react'
 import { act, create, type ReactTestRenderer } from 'react-test-renderer'
 import { afterEach, describe, expect, it, vi } from 'vitest'
-import { pairToolBlocks } from '../../../src/shared/native-chat-tool-fold'
+import { pairToolBlocks } from '../../../src/shared/native-chat/tools/native-chat-tool-pairs'
 import { nativeChatTurnMembership } from '../../../src/shared/native-chat-turn-membership'
 import type { NativeChatMessage } from '../../../src/shared/native-chat-types'
 import type { RpcClient } from '../transport/rpc-client'
diff --git a/src/main/codex/codex-collab-call-rows-on-positional-clients.test.ts b/src/main/codex/codex-collab-call-rows-on-positional-clients.test.ts
index d0bfd337b71..20a790cf6b2 100644
--- a/src/main/codex/codex-collab-call-rows-on-positional-clients.test.ts
+++ b/src/main/codex/codex-collab-call-rows-on-positional-clients.test.ts
@@ -5,8 +5,8 @@ import type {
   AgentJournalItemBody,
   AgentJournalRenderItem
 } from '../../shared/agent-session-journal-types'
-import { pairToolBlocks } from '../../shared/native-chat-tool-fold'
-import { pairNativeChatToolResults } from '../../shared/native-chat-tool-pairing'
+import { pairToolBlocks } from '../../shared/native-chat/tools/native-chat-tool-pairs'
+import { pairNativeChatToolResults } from '../../shared/native-chat/tools/native-chat-tool-pairing'
 import { projectNativeChatTranscript } from '../../shared/native-chat-transcript-projection'
 import type { NativeChatBlock, NativeChatMessage } from '../../shared/native-chat-types'
 import { projectStructuredAgentSessionMessages } from '../../shared/structured-agent-session-message-projection'
diff --git a/src/main/native-chat/agent-session-journal/journal-legacy-import-tool-pairing.test.ts b/src/main/native-chat/agent-session-journal/journal-legacy-import-tool-pairing.test.ts
index 52ed9b810aa..ac5eb4363fb 100644
--- a/src/main/native-chat/agent-session-journal/journal-legacy-import-tool-pairing.test.ts
+++ b/src/main/native-chat/agent-session-journal/journal-legacy-import-tool-pairing.test.ts
@@ -4,7 +4,8 @@ import { join } from 'node:path'
 import { afterEach, describe, expect, it } from 'vitest'
 import { agentJournalItemKey } from '../../../shared/agent-session-journal-item-key'
 import type { AgentJournalRenderItem } from '../../../shared/agent-session-journal-types'
-import { foldToolMessages, pairToolBlocks } from '../../../shared/native-chat-tool-fold'
+import { foldToolMessages } from '../../../shared/native-chat/tools/native-chat-tool-fold'
+import { pairToolBlocks } from '../../../shared/native-chat/tools/native-chat-tool-pairs'
 import { projectNativeChatTranscriptMessages } from '../../../shared/native-chat-transcript-projection'
 import { projectStructuredItemsToNativeChat } from '../../../shared/structured-agent-session-projection'
 import { prepareLegacyTranscriptImport } from './journal-legacy-import'
diff --git a/src/main/native-chat/transcript-tool-result-identity.test.ts b/src/main/native-chat/transcript-tool-result-identity.test.ts
index 1eeb3e74520..0a32eaf027e 100644
--- a/src/main/native-chat/transcript-tool-result-identity.test.ts
+++ b/src/main/native-chat/transcript-tool-result-identity.test.ts
@@ -2,7 +2,8 @@ import { mkdtemp, rm, writeFile } from 'node:fs/promises'
 import { tmpdir } from 'node:os'
 import { join } from 'node:path'
 import { afterEach, describe, expect, it } from 'vitest'
-import { foldToolMessages, pairToolBlocks } from '../../shared/native-chat-tool-fold'
+import { foldToolMessages } from '../../shared/native-chat/tools/native-chat-tool-fold'
+import { pairToolBlocks } from '../../shared/native-chat/tools/native-chat-tool-pairs'
 import type { NativeChatMessage } from '../../shared/native-chat-types'
 import { decodeClaudeTranscriptLine } from './transcript-line-decoders-claude'
 import { decodeCodexTranscriptLine } from './transcript-line-decoders-codex'
diff --git a/src/main/native-chat/transcript-window-tool-attribution.test.ts b/src/main/native-chat/transcript-window-tool-attribution.test.ts
index 306101853cb..d43a1c10186 100644
--- a/src/main/native-chat/transcript-window-tool-attribution.test.ts
+++ b/src/main/native-chat/transcript-window-tool-attribution.test.ts
@@ -4,7 +4,8 @@ import { join } from 'node:path'
 import { afterEach, describe, expect, it } from 'vitest'
 import { stripNoiseMessages } from '../../shared/native-chat-noise'
 import { mergeNativeChatMessages } from '../../shared/native-chat-merge'
-import { foldToolMessages, pairToolBlocks } from '../../shared/native-chat-tool-fold'
+import { foldToolMessages } from '../../shared/native-chat/tools/native-chat-tool-fold'
+import { pairToolBlocks } from '../../shared/native-chat/tools/native-chat-tool-pairs'
 import { isToolCallBlock, isToolResultBlock } from '../../shared/native-chat-types'
 import type { NativeChatMessage } from '../../shared/native-chat-types'
 import { decodeClaudeTranscriptLine } from './transcript-line-decoders-claude'
diff --git a/src/main/runtime/orchestration/structured-worker-journal-archive.test.ts b/src/main/runtime/orchestration/structured-worker-journal-archive.test.ts
index 7c263efc1d1..f35544bf681 100644
--- a/src/main/runtime/orchestration/structured-worker-journal-archive.test.ts
+++ b/src/main/runtime/orchestration/structured-worker-journal-archive.test.ts
@@ -2,7 +2,8 @@ import { describe, expect, it } from 'vitest'
 import type { AgentJournalRenderItem } from '../../../shared/agent-session-journal-types'
 import type { NativeChatMessage } from '../../../shared/native-chat-types'
 import { buildStructuredJournalArchive } from './structured-worker-journal-archive'
-import { foldToolMessages, pairToolBlocks } from '../../../shared/native-chat-tool-fold'
+import { foldToolMessages } from '../../../shared/native-chat/tools/native-chat-tool-fold'
+import { pairToolBlocks } from '../../../shared/native-chat/tools/native-chat-tool-pairs'
 
 const STRUCTURED_ARCHIVE_MAX_BYTES = 262_144
 
diff --git a/src/renderer/src/components/native-chat/NativeChatToolRunMemberList.tsx b/src/renderer/src/components/native-chat/NativeChatToolRunMemberList.tsx
index a79472e5f1c..be21bdb71ec 100644
--- a/src/renderer/src/components/native-chat/NativeChatToolRunMemberList.tsx
+++ b/src/renderer/src/components/native-chat/NativeChatToolRunMemberList.tsx
@@ -1,7 +1,7 @@
 import { useMemo } from 'react'
 import type { CommentMarkdownLinkClickHandler } from '@/components/sidebar/CommentMarkdown'
 import type { NativeChatBlock, NativeChatToolCallBlock } from '../../../../shared/native-chat-types'
-import { pairNativeChatToolResults } from '../../../../shared/native-chat-tool-pairing'
+import { pairNativeChatToolResults } from '../../../../shared/native-chat/tools/native-chat-tool-pairing'
 import { nativeChatToolLineIdentity } from '../../../../shared/native-chat-tool-line-identity'
 import { NativeChatDiffCard } from './NativeChatDiffCard'
 import { NativeChatTaskList } from './NativeChatTaskList'
diff --git a/src/renderer/src/components/native-chat/native-chat-message-list-projection.test.ts b/src/renderer/src/components/native-chat/native-chat-message-list-projection.test.ts
index 662d1028b74..7f849b4f456 100644
--- a/src/renderer/src/components/native-chat/native-chat-message-list-projection.test.ts
+++ b/src/renderer/src/components/native-chat/native-chat-message-list-projection.test.ts
@@ -3,8 +3,8 @@ import type { NativeChatMessage } from '../../../../shared/native-chat-types'
 import { createNativeChatMessageListProjection } from './native-chat-message-list-projection'
 import { orderNativeChatMessages } from './native-chat-message-grouping'
 import { stripNoiseMessages } from './native-chat-noise'
-import { foldToolMessages } from './native-chat-tool-fold'
-import { pairToolBlocks } from '../../../../shared/native-chat-tool-pairs'
+import { foldToolMessages } from '../../../../shared/native-chat/tools/native-chat-tool-fold'
+import { pairToolBlocks } from '../../../../shared/native-chat/tools/native-chat-tool-pairs'
 
 function message(
   id: string,
diff --git a/src/renderer/src/components/native-chat/native-chat-task-list-state.test.ts b/src/renderer/src/components/native-chat/native-chat-task-list-state.test.ts
index 5a321d191af..36eedff0a90 100644
--- a/src/renderer/src/components/native-chat/native-chat-task-list-state.test.ts
+++ b/src/renderer/src/components/native-chat/native-chat-task-list-state.test.ts
@@ -1,6 +1,6 @@
 import { describe, expect, it } from 'vitest'
 import type { NativeChatBlock, NativeChatMessage } from '../../../../shared/native-chat-types'
-import { foldToolMessages } from './native-chat-tool-fold'
+import { foldToolMessages } from '../../../../shared/native-chat/tools/native-chat-tool-fold'
 import { nativeChatTaskListState } from './native-chat-task-list-state'
 
 function message(id: string, blocks: NativeChatBlock[]): NativeChatMessage {
diff --git a/src/renderer/src/components/native-chat/native-chat-task-list-state.ts b/src/renderer/src/components/native-chat/native-chat-task-list-state.ts
index f45d6531600..1dfa9e31f21 100644
--- a/src/renderer/src/components/native-chat/native-chat-task-list-state.ts
+++ b/src/renderer/src/components/native-chat/native-chat-task-list-state.ts
@@ -3,7 +3,7 @@ import {
   type NativeChatTaskList
 } from '../../../../shared/native-chat-task-list'
 import type { NativeChatMessage } from '../../../../shared/native-chat-types'
-import { pairToolBlocks } from './native-chat-tool-fold'
+import { pairToolBlocks } from '../../../../shared/native-chat/tools/native-chat-tool-pairs'
 
 const snapshots = new WeakMap<NativeChatMessage, NativeChatTaskList | null>()
 
diff --git a/src/renderer/src/components/native-chat/native-chat-tool-fold.test.ts b/src/renderer/src/components/native-chat/native-chat-tool-fold.test.ts
index a4a8bf63a6a..0ea1602ae20 100644
--- a/src/renderer/src/components/native-chat/native-chat-tool-fold.test.ts
+++ b/src/renderer/src/components/native-chat/native-chat-tool-fold.test.ts
@@ -1,7 +1,10 @@
 import { describe, it, expect } from 'vitest'
 import type { NativeChatMessage } from '../../../../shared/native-chat-types'
 import { stripNoiseMessages } from './native-chat-noise'
-import { foldToolMessages, splitNativeChatBlocks } from './native-chat-tool-fold'
+import {
+  foldToolMessages,
+  splitNativeChatBlocks
+} from '../../../../shared/native-chat/tools/native-chat-tool-fold'
 
 function msg(
   overrides: Partial<NativeChatMessage> & Pick<NativeChatMessage, 'id'>
diff --git a/src/renderer/src/components/native-chat/native-chat-tool-fold.ts b/src/renderer/src/components/native-chat/native-chat-tool-fold.ts
deleted file mode 100644
index e18bf8f4764..00000000000
--- a/src/renderer/src/components/native-chat/native-chat-tool-fold.ts
+++ /dev/null
@@ -1,6 +0,0 @@
-export {
-  foldToolMessages,
-  pairToolBlocks,
-  splitNativeChatBlocks,
-  type NativeChatToolPair
-} from '../../../../shared/native-chat-tool-fold'
diff --git a/src/renderer/src/components/native-chat/native-chat-turn-diffs.test.ts b/src/renderer/src/components/native-chat/native-chat-turn-diffs.test.ts
index b18d78f8917..c6ae2329374 100644
--- a/src/renderer/src/components/native-chat/native-chat-turn-diffs.test.ts
+++ b/src/renderer/src/components/native-chat/native-chat-turn-diffs.test.ts
@@ -1,7 +1,7 @@
 import { MAX_EDIT_LINES } from '../../../../shared/native-chat-edit-model'
 import { describe, expect, it } from 'vitest'
 import type { NativeChatBlock, NativeChatMessage } from '../../../../shared/native-chat-types'
-import { foldToolMessages } from './native-chat-tool-fold'
+import { foldToolMessages } from '../../../../shared/native-chat/tools/native-chat-tool-fold'
 import { buildDiffSummaries, buildEditCards } from '../../../../shared/native-chat-edit-cards'
 import { nativeChatTurnDiffEditFile, nativeChatTurnDiffs } from './native-chat-turn-diffs'
 
diff --git a/src/renderer/src/components/native-chat/native-chat-work-run-pairing.test.ts b/src/renderer/src/components/native-chat/native-chat-work-run-pairing.test.ts
index c906aadb415..072d5142def 100644
--- a/src/renderer/src/components/native-chat/native-chat-work-run-pairing.test.ts
+++ b/src/renderer/src/components/native-chat/native-chat-work-run-pairing.test.ts
@@ -1,7 +1,8 @@
 import { describe, expect, it } from 'vitest'
 import type { AgentJournalRenderItem } from '../../../../shared/agent-session-journal-types'
 import type { NativeChatMessage } from '../../../../shared/native-chat-types'
-import { foldToolMessages, pairToolBlocks } from '../../../../shared/native-chat-tool-fold'
+import { foldToolMessages } from '../../../../shared/native-chat/tools/native-chat-tool-fold'
+import { pairToolBlocks } from '../../../../shared/native-chat/tools/native-chat-tool-pairs'
 import {
   nativeChatWorkRunEditKey,
   nativeChatWorkRunEntries
diff --git a/src/shared/native-chat-ask-row.ts b/src/shared/native-chat-ask-row.ts
index b5255fdee17..e1fc2544efe 100644
--- a/src/shared/native-chat-ask-row.ts
+++ b/src/shared/native-chat-ask-row.ts
@@ -6,7 +6,7 @@ import { isAskUserQuestionTool } from './agent-question-answered-intent'
 import { CODEX_ASYNC_QUESTION_TOOL } from './codex-async-question-input'
 import { parseAskFromToolInput } from './native-chat-ask'
 import { isToolCallBlock, type NativeChatBlock } from './native-chat-types'
-import { pairToolBlocks } from './native-chat-tool-fold'
+import { pairToolBlocks } from './native-chat/tools/native-chat-tool-pairs'
 
 export const NATIVE_CHAT_ASK_ROW_COPY = {
   awaiting: 'Awaiting user input:',
diff --git a/src/shared/native-chat-edit-cards.ts b/src/shared/native-chat-edit-cards.ts
index 7afd4f59816..9e880e87013 100644
--- a/src/shared/native-chat-edit-cards.ts
+++ b/src/shared/native-chat-edit-cards.ts
@@ -9,7 +9,7 @@ import {
   editFilesFromPatchText,
   type NativeChatEditFileSummary
 } from './native-chat-edit-patch-files'
-import { pairToolBlocks } from './native-chat-tool-fold'
+import { pairToolBlocks } from './native-chat/tools/native-chat-tool-pairs'
 
 /** A diff card's own words. Desktop maps these onto `translate`; mobile renders them. */
 export const NATIVE_CHAT_DIFF_CARD_COPY = {
diff --git a/src/shared/native-chat-row-content.ts b/src/shared/native-chat-row-content.ts
index 4c59cfdbe46..2a8f7120566 100644
--- a/src/shared/native-chat-row-content.ts
+++ b/src/shared/native-chat-row-content.ts
@@ -14,7 +14,7 @@ import {
   isSubagentGroupBlock,
   type NativeChatBlock
 } from './native-chat-types'
-import { splitNativeChatBlocks } from './native-chat-tool-fold'
+import { splitNativeChatBlocks } from './native-chat/tools/native-chat-tool-fold'
 import { nativeChatProseToMarkdown } from './native-chat-prose'
 
 /** Inferred from `derive` so the shape cannot drift from what it returns. */
diff --git a/src/shared/native-chat-task-list-history.ts b/src/shared/native-chat-task-list-history.ts
index 0cec64dc85f..881e12194a6 100644
--- a/src/shared/native-chat-task-list-history.ts
+++ b/src/shared/native-chat-task-list-history.ts
@@ -9,7 +9,7 @@ import type {
   NativeChatMessage,
   NativeChatToolCallBlock
 } from './native-chat-types'
-import { pairToolBlocks } from './native-chat-tool-fold'
+import { pairToolBlocks } from './native-chat/tools/native-chat-tool-pairs'
 
 export type NativeChatTaskListPredecessors = Partial<
   Record<NativeChatTaskListTool, NativeChatToolCallBlock>
diff --git a/src/shared/native-chat-transcript-contracts.test.ts b/src/shared/native-chat-transcript-contracts.test.ts
index 1395566848a..08ef1b1d528 100644
--- a/src/shared/native-chat-transcript-contracts.test.ts
+++ b/src/shared/native-chat-transcript-contracts.test.ts
@@ -1,14 +1,14 @@
 import './native-chat-reasoning-row.spec'
 import './native-chat-reasoning-order.spec'
 import './native-chat-tool-activity.spec'
-import './native-chat-tool-pair-limit.spec'
-import './native-chat-tool-fold-attribution.spec'
+import './native-chat/tools/native-chat-tool-pair-limit.spec'
+import './native-chat/tools/native-chat-tool-fold-attribution.spec'
 import './native-chat-turn-grouping.spec'
 import './native-chat-ask-row.spec'
-import './native-chat-tool-pairing.spec'
+import './native-chat/tools/native-chat-tool-pairing.spec'
 import './native-chat-live-line.spec'
 import './native-chat-merge-pairs.spec'
 import './native-chat/native-chat-command-envelope.spec'
 import './native-chat/native-chat-streaming.spec'
 import './native-chat-subagent-group-header.spec'
-import './native-chat-tool-result-orphans.spec'
+import './native-chat/tools/native-chat-tool-result-orphans.spec'
diff --git a/src/shared/native-chat-transcript-projection.ts b/src/shared/native-chat-transcript-projection.ts
index 97278ffc4e8..7c6e219f991 100644
--- a/src/shared/native-chat-transcript-projection.ts
+++ b/src/shared/native-chat-transcript-projection.ts
@@ -11,7 +11,7 @@ import { nativeChatSemanticRowId, type NativeChatMessage } from './native-chat-t
 import { compareAgentJournalPositions } from './agent-session-journal-position'
 import { agentJournalItemSubagentId } from './agent-session-journal-producer'
 import { stripNoiseMessages } from './native-chat-noise'
-import { foldToolMessages } from './native-chat-tool-fold'
+import { foldToolMessages } from './native-chat/tools/native-chat-tool-fold'
 import { foldSubagentItems } from './native-chat-subagent-items'
 import { nativeChatTurnMembership, type NativeChatTurnJournal } from './native-chat-turn-membership'
 
diff --git a/src/shared/native-chat-work-run.ts b/src/shared/native-chat-work-run.ts
index 48988a7e00e..0743370817f 100644
--- a/src/shared/native-chat-work-run.ts
+++ b/src/shared/native-chat-work-run.ts
@@ -5,7 +5,7 @@
 import { isNativeChatAskCall } from './native-chat-ask-row'
 import { deriveNativeChatRowContent } from './native-chat-row-content'
 import { isStoppedBeforeStartBlock } from './native-chat-stopped-before-start'
-import { pairToolBlocks } from './native-chat-tool-fold'
+import { pairToolBlocks } from './native-chat/tools/native-chat-tool-pairs'
 import type { NativeChatBlock, NativeChatMessage } from './native-chat-types'
 
 /** `lead`: the agent's words with calls already folded under them, which may head a run but
diff --git a/src/shared/native-chat-folded-tool-results.ts b/src/shared/native-chat/tools/native-chat-folded-tool-results.ts
similarity index 98%
rename from src/shared/native-chat-folded-tool-results.ts
rename to src/shared/native-chat/tools/native-chat-folded-tool-results.ts
index f6b5c3b81a7..926a5ab6746 100644
--- a/src/shared/native-chat-folded-tool-results.ts
+++ b/src/shared/native-chat/tools/native-chat-folded-tool-results.ts
@@ -1,5 +1,5 @@
 import { unpairedToolResultIndices } from './native-chat-tool-pairs'
-import type { NativeChatBlock, NativeChatMessage } from './native-chat-types'
+import type { NativeChatBlock, NativeChatMessage } from '../../native-chat-types'
 
 type ToolContribution = {
   source: NativeChatMessage
diff --git a/src/shared/native-chat-tool-attribution-allocation.test.ts b/src/shared/native-chat/tools/native-chat-tool-attribution-allocation.test.ts
similarity index 99%
rename from src/shared/native-chat-tool-attribution-allocation.test.ts
rename to src/shared/native-chat/tools/native-chat-tool-attribution-allocation.test.ts
index aadfcac8bc6..e663365f840 100644
--- a/src/shared/native-chat-tool-attribution-allocation.test.ts
+++ b/src/shared/native-chat/tools/native-chat-tool-attribution-allocation.test.ts
@@ -5,7 +5,7 @@ import type {
   NativeChatBackgroundTaskBlock,
   NativeChatBlock,
   NativeChatMessage
-} from './native-chat-types'
+} from '../../native-chat-types'
 
 function message(id: string, blocks: NativeChatBlock[]): NativeChatMessage {
   return {
diff --git a/src/shared/native-chat-tool-fold-attribution.spec.ts b/src/shared/native-chat/tools/native-chat-tool-fold-attribution.spec.ts
similarity index 93%
rename from src/shared/native-chat-tool-fold-attribution.spec.ts
rename to src/shared/native-chat/tools/native-chat-tool-fold-attribution.spec.ts
index 89b9772206e..9d0afe54e5f 100644
--- a/src/shared/native-chat-tool-fold-attribution.spec.ts
+++ b/src/shared/native-chat/tools/native-chat-tool-fold-attribution.spec.ts
@@ -1,6 +1,7 @@
 import { expect, it } from 'vitest'
-import { foldToolMessages, pairToolBlocks } from './native-chat-tool-fold'
-import type { NativeChatBlock, NativeChatMessage } from './native-chat-types'
+import { foldToolMessages } from './native-chat-tool-fold'
+import { pairToolBlocks } from './native-chat-tool-pairs'
+import type { NativeChatBlock, NativeChatMessage } from '../../native-chat-types'
 
 function message(id: string, blocks: NativeChatBlock[]): NativeChatMessage {
   return { id, role: 'assistant', source: 'transcript', timestamp: 1, blocks }
diff --git a/src/shared/native-chat-tool-fold.ts b/src/shared/native-chat/tools/native-chat-tool-fold.ts
similarity index 94%
rename from src/shared/native-chat-tool-fold.ts
rename to src/shared/native-chat/tools/native-chat-tool-fold.ts
index b9a6f1bfa1a..d0b5569bdc4 100644
--- a/src/shared/native-chat-tool-fold.ts
+++ b/src/shared/native-chat/tools/native-chat-tool-fold.ts
@@ -5,17 +5,15 @@ import {
   isToolResultBlock,
   type NativeChatBlock,
   type NativeChatMessage
-} from './native-chat-types'
-import { isKnownHarnessInjectedUserTurnText } from './harness-injected-user-turns'
-import { isNoiseMessage } from './native-chat-noise'
+} from '../../native-chat-types'
+import { isKnownHarnessInjectedUserTurnText } from '../../harness-injected-user-turns'
+import { isNoiseMessage } from '../../native-chat-noise'
 import {
   CODEX_PLAN_UPDATED_FRAME_KIND,
   isWordlessProviderFrameMessage
-} from './native-chat/native-chat-provider-frame-summary'
+} from '../native-chat-provider-frame-summary'
 import { FoldedToolResultSources } from './native-chat-folded-tool-results'
 
-export { pairToolBlocks, type NativeChatToolPair } from './native-chat-tool-pairs'
-
 function isToolOnlyMessage(message: NativeChatMessage): boolean {
   return (
     message.blocks.length > 0 &&
diff --git a/src/shared/native-chat-tool-pair-limit.spec.ts b/src/shared/native-chat/tools/native-chat-tool-pair-limit.spec.ts
similarity index 98%
rename from src/shared/native-chat-tool-pair-limit.spec.ts
rename to src/shared/native-chat/tools/native-chat-tool-pair-limit.spec.ts
index d54bfc9b89b..749cab49d90 100644
--- a/src/shared/native-chat-tool-pair-limit.spec.ts
+++ b/src/shared/native-chat/tools/native-chat-tool-pair-limit.spec.ts
@@ -1,6 +1,6 @@
 import { describe, expect, it } from 'vitest'
-import { pairToolBlocks, type NativeChatToolPair } from './native-chat-tool-fold'
-import type { NativeChatBlock } from './native-chat-types'
+import { pairToolBlocks, type NativeChatToolPair } from './native-chat-tool-pairs'
+import type { NativeChatBlock } from '../../native-chat-types'
 
 function original(blocks: readonly NativeChatBlock[], limit: number): NativeChatToolPair[] {
   const pairs: NativeChatToolPair[] = []
diff --git a/src/shared/native-chat-tool-pairing.performance.test.ts b/src/shared/native-chat/tools/native-chat-tool-pairing.performance.test.ts
similarity index 99%
rename from src/shared/native-chat-tool-pairing.performance.test.ts
rename to src/shared/native-chat/tools/native-chat-tool-pairing.performance.test.ts
index aef416f5239..86e970cf2e0 100644
--- a/src/shared/native-chat-tool-pairing.performance.test.ts
+++ b/src/shared/native-chat/tools/native-chat-tool-pairing.performance.test.ts
@@ -1,10 +1,10 @@
 import { describe, expect, it } from 'vitest'
-import { pairToolBlocks, type NativeChatToolPair } from './native-chat-tool-fold'
+import { pairToolBlocks, type NativeChatToolPair } from './native-chat-tool-pairs'
 import type {
   NativeChatBlock,
   NativeChatToolCallBlock,
   NativeChatToolResultBlock
-} from './native-chat-types'
+} from '../../native-chat-types'
 
 function call(callId?: string): NativeChatToolCallBlock {
   return { type: 'tool-call', name: 'Bash', input: {}, ...(callId !== undefined ? { callId } : {}) }
diff --git a/src/shared/native-chat-tool-pairing.spec.ts b/src/shared/native-chat/tools/native-chat-tool-pairing.spec.ts
similarity index 98%
rename from src/shared/native-chat-tool-pairing.spec.ts
rename to src/shared/native-chat/tools/native-chat-tool-pairing.spec.ts
index 72d7c46d656..eaae410abf9 100644
--- a/src/shared/native-chat-tool-pairing.spec.ts
+++ b/src/shared/native-chat/tools/native-chat-tool-pairing.spec.ts
@@ -4,7 +4,7 @@ import type {
   NativeChatBlock,
   NativeChatToolCallBlock,
   NativeChatToolResultBlock
-} from './native-chat-types'
+} from '../../native-chat-types'
 
 const call = (name: string): NativeChatToolCallBlock => ({ type: 'tool-call', name, input: {} })
 const result = (output: string): NativeChatToolResultBlock => ({ type: 'tool-result', output })
diff --git a/src/shared/native-chat-tool-pairing.ts b/src/shared/native-chat/tools/native-chat-tool-pairing.ts
similarity index 95%
rename from src/shared/native-chat-tool-pairing.ts
rename to src/shared/native-chat/tools/native-chat-tool-pairing.ts
index 5db9e30fa24..472f4a6cc2a 100644
--- a/src/shared/native-chat-tool-pairing.ts
+++ b/src/shared/native-chat/tools/native-chat-tool-pairing.ts
@@ -14,12 +14,12 @@
 // that has not been answered yet. Position alone misattributes every later result once
 // one call finishes with no output, which is why a producer that knows the call names it.
 
-import { pairToolBlocks } from './native-chat-tool-fold'
+import { pairToolBlocks } from './native-chat-tool-pairs'
 import type {
   NativeChatBlock,
   NativeChatToolCallBlock,
   NativeChatToolResultBlock
-} from './native-chat-types'
+} from '../../native-chat-types'
 
 export type NativeChatToolPairing = {
   /** The result each call owns. A call still running has none. */
diff --git a/src/shared/native-chat-tool-pairs.ts b/src/shared/native-chat/tools/native-chat-tool-pairs.ts
similarity index 99%
rename from src/shared/native-chat-tool-pairs.ts
rename to src/shared/native-chat/tools/native-chat-tool-pairs.ts
index 3adea0a6586..0a0adca41bb 100644
--- a/src/shared/native-chat-tool-pairs.ts
+++ b/src/shared/native-chat/tools/native-chat-tool-pairs.ts
@@ -2,7 +2,7 @@ import type {
   NativeChatBlock,
   NativeChatToolCallBlock,
   NativeChatToolResultBlock
-} from './native-chat-types'
+} from '../../native-chat-types'
 
 export type NativeChatToolPair = {
   call?: NativeChatToolCallBlock
diff --git a/src/shared/native-chat-tool-result-orphans.spec.ts b/src/shared/native-chat/tools/native-chat-tool-result-orphans.spec.ts
similarity index 94%
rename from src/shared/native-chat-tool-result-orphans.spec.ts
rename to src/shared/native-chat/tools/native-chat-tool-result-orphans.spec.ts
index 8d0c3724870..66745f598ac 100644
--- a/src/shared/native-chat-tool-result-orphans.spec.ts
+++ b/src/shared/native-chat/tools/native-chat-tool-result-orphans.spec.ts
@@ -1,14 +1,15 @@
 import { describe, expect, it } from 'vitest'
-import { foldToolMessages, pairToolBlocks } from './native-chat-tool-fold'
-import { nativeChatToolRunOutcome } from './native-chat-tool-run-outcome'
-import { nativeChatWorkRunMember } from './native-chat-work-run'
-import { nativeChatMessagesShareTranscriptRow } from './native-chat-types'
+import { foldToolMessages } from './native-chat-tool-fold'
+import { pairToolBlocks } from './native-chat-tool-pairs'
+import { nativeChatToolRunOutcome } from '../../native-chat-tool-run-outcome'
+import { nativeChatWorkRunMember } from '../../native-chat-work-run'
+import { nativeChatMessagesShareTranscriptRow } from '../../native-chat-types'
 import type {
   NativeChatBlock,
   NativeChatMessage,
   NativeChatToolCallBlock,
   NativeChatToolResultBlock
-} from './native-chat-types'
+} from '../../native-chat-types'
 
 function row(
   id: string,
diff --git a/src/shared/native-chat-turn-membership-derived-tool-row.test.ts b/src/shared/native-chat/tools/native-chat-turn-membership-derived-tool-row.test.ts
similarity index 94%
rename from src/shared/native-chat-turn-membership-derived-tool-row.test.ts
rename to src/shared/native-chat/tools/native-chat-turn-membership-derived-tool-row.test.ts
index 4252a92ea82..779c05d2126 100644
--- a/src/shared/native-chat-turn-membership-derived-tool-row.test.ts
+++ b/src/shared/native-chat/tools/native-chat-turn-membership-derived-tool-row.test.ts
@@ -1,14 +1,14 @@
 import { describe, expect, it } from 'vitest'
 import type {
   AgentJournalItemBody,
-  AgentJournalRenderItem,
-  AgentJournalTurnScope
-} from './agent-session-journal-types'
+  AgentJournalRenderItem
+} from '../../agent-session-journal-types'
+import type { AgentJournalTurnScope } from '../../agent-session-journal-turn-scope'
 import { foldToolMessages } from './native-chat-tool-fold'
-import { nativeChatRowsInDrawOrder } from './native-chat-turn-grouping'
-import { nativeChatTurnMembership } from './native-chat-turn-membership'
-import type { NativeChatMessage, NativeChatRole } from './native-chat-types'
-import { projectStructuredItemsToNativeChat } from './structured-agent-session-projection'
+import { nativeChatRowsInDrawOrder } from '../../native-chat-turn-grouping'
+import { nativeChatTurnMembership } from '../../native-chat-turn-membership'
+import type { NativeChatMessage, NativeChatRole } from '../../native-chat-types'
+import { projectStructuredItemsToNativeChat } from '../../structured-agent-session-projection'
 
 const THREAD: AgentJournalTurnScope = { kind: 'thread' }
 const inTurn = (turnItemId: string): AgentJournalTurnScope => ({ kind: 'turn', turnItemId })