diff --git a/src/main/runtime/runtime-mobile-agent-status-projection.ts b/src/main/runtime/runtime-mobile-agent-status-projection.ts
index 4ac6f32c7fe..ee0af6d268b 100644
--- a/src/main/runtime/runtime-mobile-agent-status-projection.ts
+++ b/src/main/runtime/runtime-mobile-agent-status-projection.ts
@@ -12,6 +12,46 @@ import { terminalTitleBlocksExplicitAgentStatus } from './runtime-worktree-statu
 import type { HookLiveAgentRow } from './runtime-terminal-contracts'
 import type { RuntimePtyWorktreeRecord } from './runtime-terminal-state-records'
 
+// Why: only a completed turn's reply is final; mid-turn hook snapshots carry tool stdout.
+function completedTurnFields(
+  status: AgentStatusEntry
+): Pick<
+  AgentStatusEntry,
+  'lastAssistantMessage' | 'lastAssistantMessageIsToolOutput' | 'interrupted'
+> {
+  if (status.state !== 'done') {
+    return {}
+  }
+  return {
+    ...(status.lastAssistantMessage
+      ? {
+          lastAssistantMessage: status.lastAssistantMessage,
+          ...(status.lastAssistantMessageIsToolOutput != null
+            ? { lastAssistantMessageIsToolOutput: status.lastAssistantMessageIsToolOutput }
+            : {})
+        }
+      : {}),
+    ...(status.interrupted != null ? { interrupted: status.interrupted } : {})
+  }
+}
+
+export function demoteRuntimeMobileAgentStatus(
+  status: AgentStatusEntry,
+  pty: RuntimePtyWorktreeRecord | null
+): AgentStatusEntry {
+  return {
+    state: 'done',
+    prompt: '',
+    updatedAt: pty?.lastOscTitleEpochMs ?? status.updatedAt,
+    stateStartedAt: pty?.lastAgentStatusStartedAtEpochMs ?? status.stateStartedAt,
+    paneKey: status.paneKey,
+    stateHistory: [],
+    agentType: status.agentType,
+    ...completedTurnFields(status),
+    ...(status.providerSession ? { providerSession: status.providerSession } : {})
+  }
+}
+
 export function renewRuntimeMobileAgentStatusFromPtyTitle(
   status: AgentStatusEntry | null,
   pty: RuntimePtyWorktreeRecord | null,
@@ -59,7 +99,8 @@ export function renewRuntimeMobileAgentStatusFromPtyTitle(
     ...(status.worktreeId ? { worktreeId: status.worktreeId } : {}),
     ...(status.tabId ? { tabId: status.tabId } : {}),
     ...(status.terminalTitle ? { terminalTitle: status.terminalTitle } : {}),
-    ...(status.providerSession ? { providerSession: status.providerSession } : {})
+    ...(status.providerSession ? { providerSession: status.providerSession } : {}),
+    ...(state === 'done' ? completedTurnFields(status) : {})
   })
   const titleConfirmsState =
     (pty.lastAgentStatus === 'working' && status.state === 'working') ||
diff --git a/src/main/runtime/runtime-mobile-last-assistant-message.test.ts b/src/main/runtime/runtime-mobile-last-assistant-message.test.ts
new file mode 100644
index 00000000000..bf945e6f304
--- /dev/null
+++ b/src/main/runtime/runtime-mobile-last-assistant-message.test.ts
@@ -0,0 +1,201 @@
+import { describe, expect, it, vi } from 'vitest'
+import type { AgentStatusEntry } from '../../shared/agent-status-types'
+import type { RuntimeMobileSessionTabsSnapshot } from '../../shared/runtime-types'
+import { renewRuntimeMobileAgentStatusFromPtyTitle } from './runtime-mobile-agent-status-projection'
+import { projectRuntimeMobileSessionTabs } from './runtime-mobile-session-projection'
+import type { RuntimeMobileSessionProjectionHost } from './runtime-mobile-session-projection-contract'
+import type { RuntimePtyWorktreeRecord } from './runtime-terminal-state-records'
+
+const MESSAGE = '좌→우 가로 파이프라인으로 다시 그렸습니다'
+
+function workingStatus(overrides: Partial<AgentStatusEntry> = {}): AgentStatusEntry {
+  return {
+    state: 'working',
+    prompt: 'stale task',
+    updatedAt: 1_700_000_000_000,
+    stateStartedAt: 1_699_999_999_000,
+    agentType: 'claude',
+    paneKey: 'tab:leaf',
+    terminalTitle: 'claude working',
+    lastAssistantMessage: MESSAGE,
+    interrupted: false,
+    stateHistory: [],
+    ...overrides
+  }
+}
+
+describe('mobile completion status projection', () => {
+  it.each([false, true])(
+    'keeps the completion subtitle and interrupted verdict %s under a shell title',
+    (interrupted) => {
+      // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: renew reads only the title clock and status fields this stub sets.
+      const pty = {
+        lastOscTitle: 'bash',
+        lastOscTitleEpochMs: 1_700_000_000_500,
+        lastAgentStatus: 'idle',
+        lastAgentStatusStartedAtEpochMs: 1_700_000_000_500,
+        lastAgentStatusRichInvalidatedAtEpochMs: 1_700_000_000_400
+      } as RuntimePtyWorktreeRecord
+
+      expect(
+        renewRuntimeMobileAgentStatusFromPtyTitle(
+          workingStatus({ state: 'done', interrupted }),
+          pty
+        )
+      ).toMatchObject({
+        state: 'done',
+        prompt: '',
+        agentType: 'claude',
+        lastAssistantMessage: MESSAGE,
+        interrupted
+      })
+    }
+  )
+
+  it.each(['working', 'permission'] as const)(
+    'does not carry an interrupted verdict into a new %s title',
+    (titleState) => {
+      // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: renewal reads only the title clock and status fields provided here.
+      const pty = {
+        lastOscTitle: 'Claude Code',
+        lastOscTitleEpochMs: 1_700_000_000_500,
+        lastAgentStatus: titleState,
+        lastAgentStatusStartedAtEpochMs: 1_700_000_000_500,
+        lastAgentStatusRichInvalidatedAtEpochMs: 1_700_000_000_400
+      } as RuntimePtyWorktreeRecord
+
+      const renewed = renewRuntimeMobileAgentStatusFromPtyTitle(
+        workingStatus({
+          state: 'done',
+          interrupted: true,
+          lastAssistantMessageIsToolOutput: false
+        }),
+        pty
+      )
+      expect(renewed?.state).toBe(titleState === 'working' ? 'working' : 'blocked')
+      expect(renewed?.interrupted).toBeUndefined()
+      expect(renewed?.lastAssistantMessage).toBeUndefined()
+      expect(renewed?.lastAssistantMessageIsToolOutput).toBeUndefined()
+    }
+  )
+
+  it.each([
+    { titleState: 'working', sourceState: 'done', toolOutput: false },
+    { titleState: 'working', sourceState: 'done', toolOutput: true },
+    { titleState: 'idle', sourceState: 'done', toolOutput: true },
+    { titleState: 'idle', sourceState: 'working', toolOutput: false }
+  ] as const)(
+    'keeps the reply only for a completed turn under a completed title $titleState/$sourceState/$toolOutput',
+    ({ titleState, sourceState, toolOutput }) => {
+      // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: renewal reads only the title clock and status fields provided here.
+      const pty = {
+        lastOscTitle: 'Claude Code',
+        lastOscTitleEpochMs: 1_700_000_000_500,
+        lastAgentStatus: titleState,
+        lastAgentStatusStartedAtEpochMs: 1_700_000_000_500,
+        lastAgentStatusRichInvalidatedAtEpochMs: 1_700_000_000_400
+      } as RuntimePtyWorktreeRecord
+
+      const renewed = renewRuntimeMobileAgentStatusFromPtyTitle(
+        workingStatus({ state: sourceState, lastAssistantMessageIsToolOutput: toolOutput }),
+        pty
+      )
+      expect(renewed?.state).toBe(titleState === 'working' ? 'working' : 'done')
+      if (titleState === 'working' || sourceState === 'working') {
+        expect(renewed?.lastAssistantMessage).toBeUndefined()
+        expect(renewed?.lastAssistantMessageIsToolOutput).toBeUndefined()
+      } else {
+        expect(renewed).toMatchObject({
+          lastAssistantMessage: MESSAGE,
+          lastAssistantMessageIsToolOutput: toolOutput
+        })
+      }
+    }
+  )
+
+  it.each([
+    { sourceState: 'done', toolOutput: false },
+    { sourceState: 'done', toolOutput: true },
+    { sourceState: 'working', toolOutput: false }
+  ] as const)(
+    'keeps only a completed reply when a shell leaf title demotes the mobile projection $sourceState/$toolOutput',
+    ({ sourceState, toolOutput }) => {
+      // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: the stub sets the pty fields the title clock and handle publication read.
+      const pty = {
+        ptyId: 'live-pty',
+        connected: true,
+        incarnationId: 'live-incarnation',
+        lastOscTitleEpochMs: null,
+        lastAgentStatus: null,
+        lastAgentStatusStartedAtEpochMs: null,
+        lastAgentStatusRichInvalidatedAtEpochMs: null
+      } as RuntimePtyWorktreeRecord
+      // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: the stub implements every host member this terminal projection path calls.
+      const host = {
+        tabs: new Map(),
+        leaves: new Map([
+          [
+            'leaf',
+            {
+              ptyId: pty.ptyId,
+              connected: true,
+              paneTitle: 'bash',
+              paneTitleUpdatedAt: 1
+            }
+          ]
+        ]),
+        ptysById: new Map([[pty.ptyId, pty]]),
+        getLiveBrowserTabs: () => new Map(),
+        getProviderSessionRows: () => [],
+        getProviderSessionSnapshot: () => [],
+        getLeafKey: () => 'leaf',
+        findPty: () => pty,
+        getRetainedStatus: () => null,
+        getTrackedTitle: () => null,
+        getTitleDisplayClear: () => null,
+        issuePtyHandle: vi.fn(() => 'handle'),
+        recordPty: vi.fn(() => pty),
+        buildPtyStatus: () => ({}),
+        sanitizeGroups: () => [],
+        pruneGroupLayout: () => null,
+        collectTabIds: () => new Set()
+      } as unknown as RuntimeMobileSessionProjectionHost
+      // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: one terminal tab is the only snapshot field this projection path reads.
+      const snapshot = {
+        worktree: 'workspace',
+        publicationEpoch: 'headless:epoch',
+        tabs: [
+          {
+            type: 'terminal',
+            id: 'tab::leaf',
+            parentTabId: 'tab',
+            leafId: 'leaf',
+            title: 'bash',
+            agentStatus: workingStatus({
+              state: sourceState,
+              interrupted: true,
+              lastAssistantMessageIsToolOutput: toolOutput
+            }),
+            isActive: true
+          }
+        ]
+      } as RuntimeMobileSessionTabsSnapshot
+
+      const tab = projectRuntimeMobileSessionTabs(snapshot, host).tabs[0]
+      const agentStatus = tab?.type === 'terminal' ? tab.agentStatus : undefined
+      expect(agentStatus).toMatchObject({ state: 'done', agentType: 'claude', prompt: '' })
+      expect(agentStatus?.terminalTitle).toBeUndefined()
+      if (sourceState === 'done') {
+        expect(agentStatus).toMatchObject({
+          lastAssistantMessage: MESSAGE,
+          lastAssistantMessageIsToolOutput: toolOutput,
+          interrupted: true
+        })
+      } else {
+        expect(agentStatus?.lastAssistantMessage).toBeUndefined()
+        expect(agentStatus?.lastAssistantMessageIsToolOutput).toBeUndefined()
+        expect(agentStatus?.interrupted).toBeUndefined()
+      }
+    }
+  )
+})
diff --git a/src/main/runtime/runtime-mobile-session-projection.ts b/src/main/runtime/runtime-mobile-session-projection.ts
index 2bce38db342..e5a0769c276 100644
--- a/src/main/runtime/runtime-mobile-session-projection.ts
+++ b/src/main/runtime/runtime-mobile-session-projection.ts
@@ -14,6 +14,7 @@ import { isTerminalLeafId, makePaneKey } from '../../shared/stable-pane-id'
 import { resolveTerminalTabTitle } from '../../shared/tab-title-resolution'
 import { indexAgentStatusRowsByPaneKey } from '../agent-hooks/agent-status-pane-index'
 import {
+  demoteRuntimeMobileAgentStatus,
   renewRuntimeMobileAgentStatusFromPtyTitle,
   selectRuntimeHookAgentRowForPane
 } from './runtime-mobile-agent-status-projection'
@@ -242,20 +243,7 @@ export function projectRuntimeMobileSessionTabs(
       : // Why: idle live title → drop stale "working" (no spinner) but keep agent identity so native chat can still address the transcript.
         normalizedTabAgentStatus?.agentType != null
         ? {
-            agentStatus: {
-              state: 'done' as const,
-              prompt: '',
-              updatedAt: statusPty?.lastOscTitleEpochMs ?? normalizedTabAgentStatus.updatedAt,
-              stateStartedAt:
-                statusPty?.lastAgentStatusStartedAtEpochMs ??
-                normalizedTabAgentStatus.stateStartedAt,
-              paneKey: normalizedTabAgentStatus.paneKey,
-              stateHistory: [],
-              agentType: normalizedTabAgentStatus.agentType,
-              ...(normalizedTabAgentStatus.providerSession
-                ? { providerSession: normalizedTabAgentStatus.providerSession }
-                : {})
-            }
+            agentStatus: demoteRuntimeMobileAgentStatus(normalizedTabAgentStatus, statusPty)
           }
         : null
     // Why: web/mobile clients hold handles across renderer graph syncs; leaf handles are epoch-bound but PTY handles stay streamable.