diff --git a/src/main/runtime/orca-runtime-close-mobile-session-tab.ts b/src/main/runtime/orca-runtime-close-mobile-session-tab.ts
index fa624d6f3ce..d7c32c297d4 100644
--- a/src/main/runtime/orca-runtime-close-mobile-session-tab.ts
+++ b/src/main/runtime/orca-runtime-close-mobile-session-tab.ts
@@ -18,7 +18,6 @@ import {
 } from './mobile-session-tab-close-outcome'
 import { getRuntimeBrowserPageRegistry } from './runtime-browser-page-registry'
 import type { RuntimeCommandSurfaceHost } from './orca-runtime-core'
-import { structuredAgentSessionTabId } from '../../shared/structured-agent-session-projection'
 import { SESSION_TAB_NOT_FOUND_ERROR } from '../../shared/session-tab-close'
 import { rendererPublicationThrottle } from '../window/renderer-publication-throttle'
 
@@ -296,10 +295,8 @@ export class OrcaRuntimeWithCloseMobileSessionTab extends OrcaRuntimeWithRefuseU
     } else if (tab.type === 'agent-session') {
       if (this.notifier?.closeSessionTab) {
         try {
-          await this.notifier.closeSessionTab(
-            structuredAgentSessionTabId(tab.sessionId),
-            worktreeId
-          )
+          // Why: a reopened chat's window tab id is not derivable from its session; the window maps ours.
+          await this.notifier.closeSessionTab(tab.id, worktreeId)
         } catch (error) {
           // The renderer already having removed the tab is an idempotent close, not a veto.
           if (!(error instanceof Error && error.message === SESSION_TAB_NOT_FOUND_ERROR)) {
diff --git a/src/main/runtime/orca-runtime-structured-session-restore.test.ts b/src/main/runtime/orca-runtime-structured-session-restore.test.ts
index d6ec1e22782..1d8105d07f8 100644
--- a/src/main/runtime/orca-runtime-structured-session-restore.test.ts
+++ b/src/main/runtime/orca-runtime-structured-session-restore.test.ts
@@ -307,10 +307,7 @@ describe('structured session cold restoration', () => {
       reason: 'user'
     })
 
-    expect(closeSessionTab).toHaveBeenCalledWith(
-      'structured-agent-session-restored-session',
-      'workspace-1'
-    )
+    expect(closeSessionTab).toHaveBeenCalledWith('agent-session:restored-session', 'workspace-1')
     expect(closeStructuredSession).toHaveBeenCalledWith('restored-session')
     expect(setSessionTabVisibility).toHaveBeenCalledWith('restored-session', false)
     expect(setSessionTabVisibility.mock.invocationCallOrder[0]).toBeLessThan(
diff --git a/src/renderer/src/hooks/ipc-events/host-session-tab-target.ts b/src/renderer/src/hooks/ipc-events/host-session-tab-target.ts
new file mode 100644
index 00000000000..86397dd464d
--- /dev/null
+++ b/src/renderer/src/hooks/ipc-events/host-session-tab-target.ts
@@ -0,0 +1,13 @@
+import { LOCAL_STRUCTURED_SESSION_OWNER } from '@/runtime/local-structured-session-owner'
+import { resolveLocalTabIdForHostSessionTab } from '@/runtime/web-session-tabs-sync/tracking-mappings'
+
+/** Main addresses its own session-tab ids; a mirrored chat tab lives here under a different id. */
+export function resolveWindowTabIdForHostTab(worktreeId: string, tabId: string): string {
+  return (
+    resolveLocalTabIdForHostSessionTab({
+      environmentId: LOCAL_STRUCTURED_SESSION_OWNER,
+      worktreeId,
+      hostTabId: tabId
+    }) ?? tabId
+  )
+}
diff --git a/src/renderer/src/hooks/ipc-events/session-tab-ipc-bridge.ts b/src/renderer/src/hooks/ipc-events/session-tab-ipc-bridge.ts
index 47464072034..7cd2b65efb9 100644
--- a/src/renderer/src/hooks/ipc-events/session-tab-ipc-bridge.ts
+++ b/src/renderer/src/hooks/ipc-events/session-tab-ipc-bridge.ts
@@ -13,6 +13,7 @@ import {
 } from '../../store/pinned-tab-close-guard'
 import { useAppStore } from '../../store'
 import { resolveBrowserSessionTabTarget } from './browser-session-tab-target'
+import { resolveWindowTabIdForHostTab } from './host-session-tab-target'
 
 export function registerSessionTabIpcBridge(unsubs: (() => void)[]): void {
   unsubs.push(
@@ -20,8 +21,9 @@ export function registerSessionTabIpcBridge(unsubs: (() => void)[]): void {
       if (isLocalSessionTabCloseOwned(worktreeId, tabId)) {
         return
       }
+      const localTabId = resolveWindowTabIdForHostTab(worktreeId, tabId)
       const store = useAppStore.getState()
-      const browserTarget = resolveBrowserSessionTabTarget(store, worktreeId, tabId)
+      const browserTarget = resolveBrowserSessionTabTarget(store, worktreeId, localTabId)
       if (browserTarget) {
         guardPinnedTabClose({
           isPinned: isUnifiedTabPinned(store, worktreeId, browserTarget.workspaceId),
@@ -31,11 +33,11 @@ export function registerSessionTabIpcBridge(unsubs: (() => void)[]): void {
         return
       }
       guardPinnedTabClose({
-        isPinned: isUnifiedTabPinned(store, worktreeId, tabId),
-        tabLabel: resolvePinnedTabLabel(store, worktreeId, tabId),
+        isPinned: isUnifiedTabPinned(store, worktreeId, localTabId),
+        tabLabel: resolvePinnedTabLabel(store, worktreeId, localTabId),
         onClose: () => {
           const currentStore = useAppStore.getState()
-          closeMobileSessionTabInStore(currentStore, worktreeId, tabId)
+          closeMobileSessionTabInStore(currentStore, worktreeId, localTabId)
         }
       })
     })
@@ -43,8 +45,9 @@ export function registerSessionTabIpcBridge(unsubs: (() => void)[]): void {
 
   unsubs.push(
     window.api.ui.onSessionTabCloseRequest(({ requestId, tabId, worktreeId, expiresAt }) => {
+      const localTabId = resolveWindowTabIdForHostTab(worktreeId, tabId)
       const store = useAppStore.getState()
-      const browserTarget = resolveBrowserSessionTabTarget(store, worktreeId, tabId)
+      const browserTarget = resolveBrowserSessionTabTarget(store, worktreeId, localTabId)
       let cancelConfirmation: (() => void) | undefined
       let timeout: ReturnType<typeof setTimeout> | undefined
       let settled = false
@@ -78,7 +81,11 @@ export function registerSessionTabIpcBridge(unsubs: (() => void)[]): void {
             respond()
             return
           }
-          const closed = closeMobileSessionTabInStore(useAppStore.getState(), worktreeId, tabId)
+          const closed = closeMobileSessionTabInStore(
+            useAppStore.getState(),
+            worktreeId,
+            localTabId
+          )
           respond(closed ? undefined : SESSION_TAB_NOT_FOUND_ERROR)
         } catch (error) {
           respond(error instanceof Error ? error.message : SESSION_TAB_CLOSE_FAILED_ERROR)
@@ -92,7 +99,7 @@ export function registerSessionTabIpcBridge(unsubs: (() => void)[]): void {
         )
         return
       }
-      const visibleId = browserTarget?.workspaceId ?? tabId
+      const visibleId = browserTarget?.workspaceId ?? localTabId
       cancelConfirmation = guardPinnedTabClose({
         isPinned: isUnifiedTabPinned(store, worktreeId, visibleId),
         tabLabel: resolvePinnedTabLabel(store, worktreeId, visibleId),
diff --git a/src/renderer/src/hooks/ipc-events/terminal-ui-routing-ipc-bridge.ts b/src/renderer/src/hooks/ipc-events/terminal-ui-routing-ipc-bridge.ts
index 85460c88841..29ddc098726 100644
--- a/src/renderer/src/hooks/ipc-events/terminal-ui-routing-ipc-bridge.ts
+++ b/src/renderer/src/hooks/ipc-events/terminal-ui-routing-ipc-bridge.ts
@@ -9,6 +9,7 @@ import { activateTabAndFocusPane } from '@/lib/activate-tab-and-focus-pane'
 import { useAppStore } from '../../store'
 import type { AppState } from '../../store/types'
 import { resolveBrowserSessionTabTarget } from './browser-session-tab-target'
+import { resolveWindowTabIdForHostTab } from './host-session-tab-target'
 import {
   activateTerminalInitiatedWorktree,
   focusTerminalInitiatedTab
@@ -146,9 +147,12 @@ export function registerTerminalUiRoutingIpcBridge(unsubs: (() => void)[]): void
 
   unsubs.push(
     window.api.ui.onFocusEditorTab(({ tabId, worktreeId, userInitiated }) => {
+      const localTabId = resolveWindowTabIdForHostTab(worktreeId, tabId)
       const store = useAppStore.getState()
-      const tab = (store.unifiedTabsByWorktree[worktreeId] ?? []).find((item) => item.id === tabId)
-      const browserTarget = resolveBrowserSessionTabTarget(store, worktreeId, tabId)
+      const tab = (store.unifiedTabsByWorktree[worktreeId] ?? []).find(
+        (item) => item.id === localTabId
+      )
+      const browserTarget = resolveBrowserSessionTabTarget(store, worktreeId, localTabId)
       // Why: chat-completion focus is a courtesy reveal, not navigation — never yank the user
       // back into a workspace they deliberately left. A notification click is the opposite: the
       // user asked for this workspace, and the activateWorktree that precedes it is async, so
diff --git a/src/renderer/src/runtime/structured-agent-session-tab-retirement.test.ts b/src/renderer/src/runtime/structured-agent-session-tab-retirement.test.ts
index 7963b1c150e..5c3017998c0 100644
--- a/src/renderer/src/runtime/structured-agent-session-tab-retirement.test.ts
+++ b/src/renderer/src/runtime/structured-agent-session-tab-retirement.test.ts
@@ -84,7 +84,6 @@ describe('structured agent session tab retirement', () => {
     beginStructuredAgentSessionTabClose({
       target,
       worktreeId: 'wt-1',
-      tabId: 'agent-tab-1',
       sessionId: 'session-1',
       provisional: true
     })
@@ -119,13 +118,11 @@ describe('structured agent session tab retirement', () => {
     retireStructuredAgentSessionTab({
       target,
       worktreeId: 'wt-1',
-      tabId: 'agent-tab-1',
       sessionId: 'session-1'
     })
     retireStructuredAgentSessionTab({
       target,
       worktreeId: 'wt-1',
-      tabId: 'agent-tab-1',
       sessionId: 'session-1'
     })
     expect(mocks.closeSession).toHaveBeenCalledTimes(1)
diff --git a/src/renderer/src/runtime/structured-agent-session-tab-retirement.ts b/src/renderer/src/runtime/structured-agent-session-tab-retirement.ts
index 8489aa0e6a6..567e7459603 100644
--- a/src/renderer/src/runtime/structured-agent-session-tab-retirement.ts
+++ b/src/renderer/src/runtime/structured-agent-session-tab-retirement.ts
@@ -19,7 +19,6 @@ function retirementKey(target: RuntimeClientTarget, worktreeId: string, sessionI
 export function retireStructuredAgentSessionTab(args: {
   target: RuntimeClientTarget
   worktreeId: string
-  tabId: string
   sessionId: string
   onError?: (error: unknown) => void
 }): void {
@@ -28,11 +27,13 @@ export function retireStructuredAgentSessionTab(args: {
   if (existing) {
     return
   }
+  const hostTabId = `agent-session:${args.sessionId}`
+  // Why: main echoes the host tab id it was asked to close, never this window's tab id.
   const closeHostTab = () =>
-    withLocalSessionTabCloseOwner(args.worktreeId, args.tabId, () =>
+    withLocalSessionTabCloseOwner(args.worktreeId, hostTabId, () =>
       callRuntimeRpc(args.target, 'session.tabs.close', {
         worktree: toRuntimeWorktreeSelector(args.worktreeId),
-        tabId: `agent-session:${args.sessionId}`,
+        tabId: hostTabId,
         reason: 'user'
       })
     )
@@ -58,7 +59,6 @@ export function retireStructuredAgentSessionTab(args: {
 export function beginStructuredAgentSessionTabClose(args: {
   target: RuntimeClientTarget
   worktreeId: string
-  tabId: string
   sessionId: string
   provisional: boolean
   onError?: (error: unknown) => void
@@ -92,7 +92,6 @@ export function suppressCancelledStructuredSessionTabs(
     retireStructuredAgentSessionTab({
       target,
       worktreeId: snapshot.worktree,
-      tabId: `agent-session:${sessionId}`,
       sessionId,
       onError
     })
diff --git a/src/renderer/src/runtime/web-session-tabs-sync/tracking-mappings.ts b/src/renderer/src/runtime/web-session-tabs-sync/tracking-mappings.ts
index 83f8633f253..ed6ba998a1e 100644
--- a/src/renderer/src/runtime/web-session-tabs-sync/tracking-mappings.ts
+++ b/src/renderer/src/runtime/web-session-tabs-sync/tracking-mappings.ts
@@ -73,3 +73,20 @@ export function hostSessionTabIdsByLocalTabForWorktree(
   }
   return entries
 }
+
+/** The local tab mirroring a host tab, or null when no mirrored tab claims it. */
+export function resolveLocalTabIdForHostSessionTab(args: {
+  environmentId: string
+  worktreeId: string
+  hostTabId: string
+}): string | null {
+  for (const [tabId, hostTabId] of hostSessionTabIdsByLocalTabForWorktree(
+    args.environmentId,
+    args.worktreeId
+  )) {
+    if (hostTabId === args.hostTabId) {
+      return tabId
+    }
+  }
+  return null
+}
diff --git a/src/renderer/src/store/slices/tabs/tabs-close-actions.ts b/src/renderer/src/store/slices/tabs/tabs-close-actions.ts
index 35a7be70ced..b9187c8b0d8 100644
--- a/src/renderer/src/store/slices/tabs/tabs-close-actions.ts
+++ b/src/renderer/src/store/slices/tabs/tabs-close-actions.ts
@@ -64,7 +64,6 @@ export function createTabsCloseActions(
             activeRuntimeEnvironmentId: getRuntimeEnvironmentIdForWorktree(state, worktreeId)
           }),
           worktreeId,
-          tabId: tab.id,
           sessionId: tab.entityId,
           provisional
         })
diff --git a/tests/e2e/structured-session-reopened-tab-close.unit.test.ts b/tests/e2e/structured-session-reopened-tab-close.unit.test.ts
new file mode 100644
index 00000000000..35547145c32
--- /dev/null
+++ b/tests/e2e/structured-session-reopened-tab-close.unit.test.ts
@@ -0,0 +1,231 @@
+// @vitest-environment happy-dom
+
+/**
+ * After /clear the current chat keeps the tab id derived from its first session, so reopening that
+ * first session from history lands in a suffixed tab. Closing or focusing the reopened tab from
+ * main must reach that tab, not the current chat. Runs the real main close/focus path against the
+ * real window store, mirror and IPC bridges; only the process boundary is stubbed.
+ */
+
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+import type { RuntimeMobileSessionTabsResult } from '../../src/shared/runtime-types'
+import type * as RuntimeRpcClient from '../../src/renderer/src/runtime/runtime-rpc-client'
+import { OrcaRuntimeService } from '../../src/main/runtime/orca-runtime'
+import { setStructuredAgentSessionHost } from '../../src/main/native-chat/agent-session-wire/structured-agent-session-registry'
+import { useAppStore } from '../../src/renderer/src/store'
+import { applyStructuredSessionTabSnapshots } from '../../src/renderer/src/runtime/local-structured-session-tabs-sync/snapshot-apply'
+import { resetLocalStructuredSessionVersionForTests } from '../../src/renderer/src/runtime/local-structured-session-tabs-sync'
+import { resetWebSessionTabsSnapshotFreshnessForTests } from '../../src/renderer/src/runtime/web-session-tabs-sync'
+import { registerSessionTabIpcBridge } from '../../src/renderer/src/hooks/ipc-events/session-tab-ipc-bridge'
+import { registerTerminalUiRoutingIpcBridge } from '../../src/renderer/src/hooks/ipc-events/terminal-ui-routing-ipc-bridge'
+
+const WORKTREE = 'repo-1::/tmp/wt-reopen'
+const CURRENT_SESSION = 'clear-x'
+const REOPENED_SESSION = 'session-s'
+const CURRENT_TAB = `structured-agent-session-${REOPENED_SESSION}`
+const REOPENED_TAB = `${CURRENT_TAB}:history-1`
+
+type CloseRequest = { requestId: string; tabId: string; worktreeId: string; expiresAt?: number }
+type Listener<T> = (payload: T) => void
+
+type ProcessBoundary = {
+  runtime: Pick<OrcaRuntimeService, 'closeMobileSessionTab'> | null
+  rendererSessionCloses: string[]
+}
+
+const bridge = vi.hoisted((): ProcessBoundary => ({
+  runtime: null,
+  rendererSessionCloses: []
+}))
+
+vi.mock('../../src/renderer/src/runtime/runtime-rpc-client', async (importOriginal) => {
+  const actual = await importOriginal<typeof RuntimeRpcClient>()
+  return {
+    ...actual,
+    callRuntimeRpc: async (
+      _target: unknown,
+      method: string,
+      params: { worktree: string; tabId: string; reason?: 'user' }
+    ) => {
+      if (method !== 'session.tabs.close') {
+        throw new Error(`unexpected rpc ${method}`)
+      }
+      return bridge.runtime!.closeMobileSessionTab(params.worktree, params.tabId, {
+        reason: params.reason
+      })
+    }
+  }
+})
+
+vi.mock('../../src/renderer/src/runtime/structured-agent-session-close', () => ({
+  closeStructuredAgentSession: async (_target: unknown, sessionId: string) => {
+    bridge.rendererSessionCloses.push(sessionId)
+    return 'closed'
+  }
+}))
+
+async function setup() {
+  const listeners: {
+    closeSessionTab?: Listener<{ tabId: string; worktreeId: string }>
+    closeRequest?: Listener<CloseRequest>
+    focusEditorTab?: Listener<{ tabId: string; worktreeId: string; userInitiated?: boolean }>
+  } = {}
+  const pendingResponses = new Map<string, (error?: string) => void>()
+  const register =
+    <T>(assign: (listener: Listener<T>) => void) =>
+    (listener: Listener<T>) => {
+      assign(listener)
+      return () => {}
+    }
+  const noop = () => () => {}
+  vi.stubGlobal('api', {
+    ui: {
+      onCloseSessionTab: register((l) => (listeners.closeSessionTab = l)),
+      onSessionTabCloseRequest: register((l) => (listeners.closeRequest = l)),
+      onFocusEditorTab: register((l) => (listeners.focusEditorTab = l)),
+      onMoveSessionTab: noop,
+      onSplitTerminal: noop,
+      onRenameTerminal: noop,
+      onFocusTerminal: noop,
+      respondSessionTabClose: ({ requestId, error }: { requestId: string; error?: string }) =>
+        pendingResponses.get(requestId)?.(error)
+    }
+  })
+  registerSessionTabIpcBridge([])
+  registerTerminalUiRoutingIpcBridge([])
+
+  const hostSessionCloses: string[] = []
+  const closeResponses: (string | undefined)[] = []
+  const runtime = new OrcaRuntimeService()
+  bridge.runtime = runtime
+  let nextRequest = 0
+  runtime.setNotifier(
+    // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: the chat close and focus paths call only these two notifier members.
+    {
+      // Same contract as the window relay: a request the renderer answers with an optional error.
+      closeSessionTab: (tabId: string, worktreeId: string) =>
+        new Promise<void>((resolve, reject) => {
+          const requestId = `close-${++nextRequest}`
+          pendingResponses.set(requestId, (error) => {
+            closeResponses.push(error)
+            return error ? reject(new Error(error)) : resolve()
+          })
+          listeners.closeRequest!({ requestId, tabId, worktreeId })
+        }),
+      focusEditorTab: (tabId: string, worktreeId: string) =>
+        listeners.focusEditorTab!({ tabId, worktreeId })
+    } as never
+  )
+  // No durable store, PTYs or workspace session on disk: the host tab list below is the whole state.
+  Object.assign(runtime, {
+    hasPersistedStructuredAgentSessionStore: () => true,
+    getKnownWorkspaceSessionWorktreeIds: () => new Set(),
+    hydrateHeadlessMobileSessionTabsFromWorkspaceSession: () => new Set(),
+    refreshMobileSessionPtyRecords: async () => new Set(),
+    ensureStructuredAgentSessionHost: async () => undefined
+  })
+  setStructuredAgentSessionHost(
+    // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: restore and tab close call only these host members.
+    {
+      reconcileRestartLeases: async () => undefined,
+      restoreReadableSessions: async () => undefined,
+      close: async (sessionId: string) => {
+        hostSessionCloses.push(sessionId)
+      },
+      setSessionTabVisibility: async () => undefined,
+      listSessionTabs: () => [
+        { sessionId: CURRENT_SESSION, workspaceId: WORKTREE, agent: 'claude' },
+        { sessionId: REOPENED_SESSION, workspaceId: WORKTREE, agent: 'claude' }
+      ]
+    } as never
+  )
+  await runtime.restoreStructuredAgentSessionTabs()
+  const hostSnapshot: RuntimeMobileSessionTabsResult = await runtime.listMobileSessionTabs(
+    `id:${WORKTREE}`
+  )
+
+  // The current chat after /clear: first session's tab id, new session's entity.
+  useAppStore.setState({ activeWorktreeId: WORKTREE })
+  useAppStore.getState().createUnifiedTab(WORKTREE, 'agent-session', {
+    id: CURRENT_TAB,
+    entityId: CURRENT_SESSION,
+    label: 'Claude Chat'
+  })
+  applyStructuredSessionTabSnapshots([hostSnapshot])
+
+  const agentTabs = () =>
+    (useAppStore.getState().unifiedTabsByWorktree[WORKTREE] ?? [])
+      .filter((tab) => tab.contentType === 'agent-session')
+      .map((tab) => ({ id: tab.id, entityId: tab.entityId }))
+  return { runtime, agentTabs, hostSessionCloses, closeResponses }
+}
+
+const initialStoreState = useAppStore.getState()
+
+beforeEach(() => {
+  bridge.rendererSessionCloses = []
+})
+
+afterEach(() => {
+  setStructuredAgentSessionHost(null)
+  bridge.runtime = null
+  useAppStore.setState(initialStoreState, true)
+  resetLocalStructuredSessionVersionForTests()
+  resetWebSessionTabsSnapshotFreshnessForTests()
+  vi.unstubAllGlobals()
+})
+
+describe('closing a chat reopened from history after /clear', () => {
+  it('mirrors the reopened session into a suffixed tab beside the current chat', async () => {
+    const { agentTabs } = await setup()
+
+    expect(agentTabs()).toEqual(
+      expect.arrayContaining([
+        { id: CURRENT_TAB, entityId: CURRENT_SESSION },
+        { id: REOPENED_TAB, entityId: REOPENED_SESSION }
+      ])
+    )
+  })
+
+  it('closes only the reopened tab when the user closes it on the desktop', async () => {
+    const { agentTabs, hostSessionCloses, closeResponses } = await setup()
+
+    useAppStore.getState().closeUnifiedTab(REOPENED_TAB)
+
+    await vi.waitFor(() => expect(hostSessionCloses).toEqual([REOPENED_SESSION]))
+    // Let any stray echo reach the window before asserting the current chat survived.
+    await new Promise((resolve) => setTimeout(resolve, 0))
+    expect(agentTabs()).toEqual([{ id: CURRENT_TAB, entityId: CURRENT_SESSION }])
+    expect(bridge.rendererSessionCloses).toEqual([REOPENED_SESSION])
+    expect(hostSessionCloses).toEqual([REOPENED_SESSION])
+    // The window already removed the tab, so main's relay is acknowledged, not reported missing.
+    expect(closeResponses).toEqual([undefined])
+  })
+
+  it('closes only the reopened tab when a phone closes it through the runtime', async () => {
+    const { runtime, agentTabs, hostSessionCloses } = await setup()
+
+    await runtime.closeMobileSessionTab(`id:${WORKTREE}`, `agent-session:${REOPENED_SESSION}`, {
+      reason: 'user'
+    })
+
+    await vi.waitFor(() =>
+      expect(agentTabs()).toEqual([{ id: CURRENT_TAB, entityId: CURRENT_SESSION }])
+    )
+    expect(bridge.rendererSessionCloses).not.toContain(CURRENT_SESSION)
+    expect(hostSessionCloses).not.toContain(CURRENT_SESSION)
+  })
+
+  it('focuses the reopened tab when a phone activates it through the runtime', async () => {
+    const { runtime } = await setup()
+    useAppStore.getState().activateTab(CURRENT_TAB, { worktreeId: WORKTREE })
+
+    await runtime.activateMobileSessionTab(`id:${WORKTREE}`, `agent-session:${REOPENED_SESSION}`)
+
+    const state = useAppStore.getState()
+    const group = state.groupsByWorktree[WORKTREE]?.find((candidate) =>
+      candidate.tabOrder.includes(REOPENED_TAB)
+    )
+    expect(group?.activeTabId).toBe(REOPENED_TAB)
+  })
+})