diff --git a/docs/.generated/plugin-sdk-api-baseline.sha256 b/docs/.generated/plugin-sdk-api-baseline.sha256
index e086e690a94..eafa67247ca 100644
--- a/docs/.generated/plugin-sdk-api-baseline.sha256
+++ b/docs/.generated/plugin-sdk-api-baseline.sha256
@@ -1,2 +1,2 @@
-4ec700ac180b7eca81ca48885bc7f645dbf5016e2438e44678f4c206eed4b643  plugin-sdk-api-baseline.json
-ff0d1541e7220c67d97444304568285303e423770bd6af6227afdf470bf233cc  plugin-sdk-api-baseline.jsonl
+c1d52cab340bc37d6750de609ba565598cbfc883291786092b0bfebec9d0c926  plugin-sdk-api-baseline.json
+d03fa4539c6a2f0a138da3c658543315ad56648c3fd375591d09253d5db09298  plugin-sdk-api-baseline.jsonl
diff --git a/src/commands/tasks.ts b/src/commands/tasks.ts
index cb111ed647c..65dc46778d7 100644
--- a/src/commands/tasks.ts
+++ b/src/commands/tasks.ts
@@ -531,7 +531,7 @@ export async function tasksMaintenanceCommand(
 
   runtime.log(
     info(
-      `Tasks maintenance (${opts.apply ? "applied" : "preview"}): tasks ${taskMaintenance.reconciled} reconcile · ${taskMaintenance.cleanupStamped} cleanup stamp · ${taskMaintenance.pruned} prune; task-flows ${flowMaintenance.reconciled} reconcile · ${flowMaintenance.pruned} prune`,
+      `Tasks maintenance (${opts.apply ? "applied" : "preview"}): tasks ${taskMaintenance.reconciled} reconcile · ${taskMaintenance.recovered} recovered · ${taskMaintenance.cleanupStamped} cleanup stamp · ${taskMaintenance.pruned} prune; task-flows ${flowMaintenance.reconciled} reconcile · ${flowMaintenance.pruned} prune`,
     ),
   );
   runtime.log(
diff --git a/src/tasks/detached-task-runtime-contract.ts b/src/tasks/detached-task-runtime-contract.ts
index e1e82d9f09f..018f8115a24 100644
--- a/src/tasks/detached-task-runtime-contract.ts
+++ b/src/tasks/detached-task-runtime-contract.ts
@@ -97,6 +97,17 @@ export type DetachedTaskCancelResult = {
   task?: TaskRecord;
 };
 
+export type DetachedTaskRecoveryAttemptParams = {
+  taskId: string;
+  runtime: TaskRuntime;
+  task: TaskRecord;
+  now: number;
+};
+
+export type DetachedTaskRecoveryAttemptResult = {
+  recovered: boolean;
+};
+
 export type DetachedTaskLifecycleRuntime = {
   createQueuedTaskRun: (params: DetachedTaskCreateParams) => TaskRecord;
   createRunningTaskRun: (params: DetachedRunningTaskCreateParams) => TaskRecord;
@@ -112,6 +123,13 @@ export type DetachedTaskLifecycleRuntime = {
   cancelDetachedTaskRunById: (
     params: DetachedTaskCancelParams,
   ) => Promise<DetachedTaskCancelResult>;
+  /**
+   * Give a registered detached runtime one last chance to recover a stale task
+   * before core marks it lost during maintenance.
+   */
+  tryRecoverTaskBeforeMarkLost?: (
+    params: DetachedTaskRecoveryAttemptParams,
+  ) => DetachedTaskRecoveryAttemptResult | Promise<DetachedTaskRecoveryAttemptResult>;
 };
 
 export type DetachedTaskLifecycleRuntimeRegistration = {
diff --git a/src/tasks/detached-task-runtime.test.ts b/src/tasks/detached-task-runtime.test.ts
index 26eaea3280f..01ae49d1376 100644
--- a/src/tasks/detached-task-runtime.test.ts
+++ b/src/tasks/detached-task-runtime.test.ts
@@ -13,9 +13,28 @@ import {
   setDetachedTaskLifecycleRuntime,
   setDetachedTaskDeliveryStatusByRunId,
   startTaskRunByRunId,
+  tryRecoverTaskBeforeMarkLost,
 } from "./detached-task-runtime.js";
 import type { TaskRecord } from "./task-registry.types.js";
 
+const { mockLogWarn } = vi.hoisted(() => ({
+  mockLogWarn: vi.fn(),
+}));
+vi.mock("../logging/subsystem.js", () => ({
+  createSubsystemLogger: () => ({
+    subsystem: "tasks/detached-runtime",
+    isEnabled: () => true,
+    trace: vi.fn(),
+    debug: vi.fn(),
+    info: vi.fn(),
+    warn: mockLogWarn,
+    error: vi.fn(),
+    fatal: vi.fn(),
+    raw: vi.fn(),
+    child: vi.fn(),
+  }),
+}));
+
 function createFakeTaskRecord(overrides?: Partial<TaskRecord>): TaskRecord {
   return {
     taskId: "task-fake",
@@ -36,6 +55,7 @@ function createFakeTaskRecord(overrides?: Partial<TaskRecord>): TaskRecord {
 describe("detached-task-runtime", () => {
   afterEach(() => {
     resetDetachedTaskLifecycleRuntimeForTests();
+    mockLogWarn.mockClear();
   });
 
   it("dispatches lifecycle operations through the installed runtime", async () => {
@@ -145,4 +165,109 @@ describe("detached-task-runtime", () => {
     });
     expect(getDetachedTaskLifecycleRuntime()).toBe(runtime);
   });
+
+  describe("tryRecoverTaskBeforeMarkLost", () => {
+    it("returns recovered when hook returns recovered true", async () => {
+      const task = createFakeTaskRecord({ taskId: "task-recover", runtime: "subagent" });
+      setDetachedTaskLifecycleRuntime({
+        ...getDetachedTaskLifecycleRuntime(),
+        tryRecoverTaskBeforeMarkLost: vi.fn(() => ({ recovered: true })),
+      });
+      const result = await tryRecoverTaskBeforeMarkLost({
+        taskId: task.taskId,
+        runtime: task.runtime,
+        task,
+        now: 123,
+      });
+      expect(result).toEqual({ recovered: true });
+    });
+
+    it("returns not recovered when hook returns recovered false", async () => {
+      const task = createFakeTaskRecord({ taskId: "task-no-recover", runtime: "cron" });
+      setDetachedTaskLifecycleRuntime({
+        ...getDetachedTaskLifecycleRuntime(),
+        tryRecoverTaskBeforeMarkLost: vi.fn(() => ({ recovered: false })),
+      });
+      const result = await tryRecoverTaskBeforeMarkLost({
+        taskId: task.taskId,
+        runtime: task.runtime,
+        task,
+        now: 456,
+      });
+      expect(result).toEqual({ recovered: false });
+    });
+
+    it("returns not recovered when hook is not provided", async () => {
+      const task = createFakeTaskRecord({ taskId: "task-no-hook", runtime: "cli" });
+      const result = await tryRecoverTaskBeforeMarkLost({
+        taskId: task.taskId,
+        runtime: task.runtime,
+        task,
+        now: 789,
+      });
+      expect(result).toEqual({ recovered: false });
+    });
+
+    it("returns not recovered and logs warning when hook throws", async () => {
+      const task = createFakeTaskRecord({ taskId: "task-throw", runtime: "acp" });
+      setDetachedTaskLifecycleRuntime({
+        ...getDetachedTaskLifecycleRuntime(),
+        tryRecoverTaskBeforeMarkLost: vi.fn(() => {
+          throw new Error("plugin crashed");
+        }),
+      });
+      const result = await tryRecoverTaskBeforeMarkLost({
+        taskId: task.taskId,
+        runtime: task.runtime,
+        task,
+        now: 1_000,
+      });
+      expect(result).toEqual({ recovered: false });
+      expect(mockLogWarn).toHaveBeenCalledWith(
+        "Detached task recovery hook threw, proceeding with markTaskLost",
+        expect.objectContaining({ taskId: "task-throw", runtime: "acp", elapsedMs: 0 }),
+      );
+    });
+
+    it("returns not recovered and logs warning when hook returns invalid result", async () => {
+      const task = createFakeTaskRecord({ taskId: "task-invalid", runtime: "cron" });
+      setDetachedTaskLifecycleRuntime({
+        ...getDetachedTaskLifecycleRuntime(),
+        tryRecoverTaskBeforeMarkLost: vi.fn(() => ({ nope: true }) as never),
+      });
+      const result = await tryRecoverTaskBeforeMarkLost({
+        taskId: task.taskId,
+        runtime: task.runtime,
+        task,
+        now: 2_000,
+      });
+      expect(result).toEqual({ recovered: false });
+      expect(mockLogWarn).toHaveBeenCalledWith(
+        "Detached task recovery hook returned invalid result, proceeding with markTaskLost",
+        expect.objectContaining({ taskId: "task-invalid", runtime: "cron" }),
+      );
+    });
+
+    it("logs when the recovery hook is slow", async () => {
+      const task = createFakeTaskRecord({ taskId: "task-slow", runtime: "subagent" });
+      const dateNowSpy = vi.spyOn(Date, "now");
+      dateNowSpy.mockReturnValueOnce(10_000).mockReturnValueOnce(16_000);
+      setDetachedTaskLifecycleRuntime({
+        ...getDetachedTaskLifecycleRuntime(),
+        tryRecoverTaskBeforeMarkLost: vi.fn(async () => ({ recovered: true })),
+      });
+      const result = await tryRecoverTaskBeforeMarkLost({
+        taskId: task.taskId,
+        runtime: task.runtime,
+        task,
+        now: 3_000,
+      });
+      expect(result).toEqual({ recovered: true });
+      expect(mockLogWarn).toHaveBeenCalledWith(
+        "Detached task recovery hook was slow",
+        expect.objectContaining({ taskId: "task-slow", runtime: "subagent", elapsedMs: 6_000 }),
+      );
+      dateNowSpy.mockRestore();
+    });
+  });
 });
diff --git a/src/tasks/detached-task-runtime.ts b/src/tasks/detached-task-runtime.ts
index 643f15af13f..a62042177c8 100644
--- a/src/tasks/detached-task-runtime.ts
+++ b/src/tasks/detached-task-runtime.ts
@@ -1,4 +1,7 @@
+import { createSubsystemLogger } from "../logging/subsystem.js";
 import type {
+  DetachedTaskRecoveryAttemptParams,
+  DetachedTaskRecoveryAttemptResult,
   DetachedTaskLifecycleRuntime,
   DetachedTaskLifecycleRuntimeRegistration,
 } from "./detached-task-runtime-contract.js";
@@ -19,6 +22,9 @@ import {
   startTaskRunByRunId as startTaskRunByRunIdFromExecutor,
 } from "./task-executor.js";
 
+const log = createSubsystemLogger("tasks/detached-runtime");
+const DETACHED_TASK_RECOVERY_WARN_MS = 5_000;
+
 export type { DetachedTaskLifecycleRuntime, DetachedTaskLifecycleRuntimeRegistration };
 
 const DEFAULT_DETACHED_TASK_LIFECYCLE_RUNTIME: DetachedTaskLifecycleRuntime = {
@@ -104,3 +110,41 @@ export function cancelDetachedTaskRunById(
 ): ReturnType<DetachedTaskLifecycleRuntime["cancelDetachedTaskRunById"]> {
   return getDetachedTaskLifecycleRuntime().cancelDetachedTaskRunById(...args);
 }
+
+export async function tryRecoverTaskBeforeMarkLost(
+  params: DetachedTaskRecoveryAttemptParams,
+): Promise<DetachedTaskRecoveryAttemptResult> {
+  const hook = getDetachedTaskLifecycleRuntime().tryRecoverTaskBeforeMarkLost;
+  if (!hook) {
+    return { recovered: false };
+  }
+  const startedAt = Date.now();
+  try {
+    const result = await hook(params);
+    const elapsedMs = Date.now() - startedAt;
+    if (elapsedMs >= DETACHED_TASK_RECOVERY_WARN_MS) {
+      log.warn("Detached task recovery hook was slow", {
+        taskId: params.taskId,
+        runtime: params.runtime,
+        elapsedMs,
+      });
+    }
+    if (result && typeof result.recovered === "boolean") {
+      return result;
+    }
+    log.warn("Detached task recovery hook returned invalid result, proceeding with markTaskLost", {
+      taskId: params.taskId,
+      runtime: params.runtime,
+      result,
+    });
+    return { recovered: false };
+  } catch (err) {
+    log.warn("Detached task recovery hook threw, proceeding with markTaskLost", {
+      taskId: params.taskId,
+      runtime: params.runtime,
+      elapsedMs: Date.now() - startedAt,
+      error: err,
+    });
+    return { recovered: false };
+  }
+}
diff --git a/src/tasks/task-registry.maintenance.issue-60299.test.ts b/src/tasks/task-registry.maintenance.issue-60299.test.ts
index 59af8e61658..239e7f97733 100644
--- a/src/tasks/task-registry.maintenance.issue-60299.test.ts
+++ b/src/tasks/task-registry.maintenance.issue-60299.test.ts
@@ -1,8 +1,14 @@
-import { afterEach, describe, expect, it } from "vitest";
+import { afterEach, describe, expect, it, vi } from "vitest";
 import type { AcpSessionStoreEntry } from "../acp/runtime/session-meta.js";
 import type { SessionEntry } from "../config/sessions.js";
 import type { ParsedAgentSessionKey } from "../routing/session-key.js";
 import {
+  resetDetachedTaskLifecycleRuntimeForTests,
+  setDetachedTaskLifecycleRuntime,
+  getDetachedTaskLifecycleRuntime,
+} from "./detached-task-runtime.js";
+import {
+  previewTaskRegistryMaintenance,
   resetTaskRegistryMaintenanceRuntimeForTests,
   runTaskRegistryMaintenance,
   setTaskRegistryMaintenanceRuntimeForTests,
@@ -38,6 +44,7 @@ type TaskRegistryMaintenanceRuntime = Parameters<
 afterEach(() => {
   stopTaskRegistryMaintenanceForTests();
   resetTaskRegistryMaintenanceRuntimeForTests();
+  resetDetachedTaskLifecycleRuntimeForTests();
 });
 
 function createTaskRegistryMaintenanceHarness(params: {
@@ -197,4 +204,35 @@ describe("task-registry maintenance issue #60299", () => {
     expect(await runTaskRegistryMaintenance()).toMatchObject({ reconciled: 0 });
     expect(currentTasks.get(task.taskId)).toMatchObject({ status: "running" });
   });
+
+  it("skips markTaskLost and counts recovered when recovery hook recovers a stale task", async () => {
+    const task = makeStaleTask({
+      runtime: "cron",
+      sourceId: "cron-job-recovered",
+      childSessionKey: undefined,
+    });
+
+    const { currentTasks } = createTaskRegistryMaintenanceHarness({
+      tasks: [task],
+    });
+
+    const recoveryHook = vi.fn(() => ({ recovered: true }));
+    setDetachedTaskLifecycleRuntime({
+      ...getDetachedTaskLifecycleRuntime(),
+      tryRecoverTaskBeforeMarkLost: recoveryHook,
+    });
+
+    expect(previewTaskRegistryMaintenance()).toMatchObject({ reconciled: 1, recovered: 0 });
+    const result = await runTaskRegistryMaintenance();
+    expect(result).toMatchObject({ reconciled: 0, recovered: 1 });
+    expect(currentTasks.get(task.taskId)).toMatchObject({ status: "running" });
+    expect(recoveryHook).toHaveBeenCalledWith(
+      expect.objectContaining({
+        taskId: task.taskId,
+        runtime: "cron",
+        task: expect.objectContaining({ taskId: task.taskId }),
+        now: expect.any(Number),
+      }),
+    );
+  });
 });
diff --git a/src/tasks/task-registry.maintenance.ts b/src/tasks/task-registry.maintenance.ts
index afb47b075aa..eb1257f4ceb 100644
--- a/src/tasks/task-registry.maintenance.ts
+++ b/src/tasks/task-registry.maintenance.ts
@@ -5,6 +5,7 @@ import { getAgentRunContext } from "../infra/agent-events.js";
 import { parseAgentSessionKey } from "../routing/session-key.js";
 import { deriveSessionChatType } from "../sessions/session-chat-type.js";
 import { normalizeLowercaseStringOrEmpty } from "../shared/string-coerce.js";
+import { tryRecoverTaskBeforeMarkLost } from "./detached-task-runtime.js";
 import {
   deleteTaskRecordById,
   ensureTaskRegistryReady,
@@ -77,6 +78,7 @@ let taskRegistryMaintenanceRuntime: TaskRegistryMaintenanceRuntime =
 
 export type TaskRegistryMaintenanceSummary = {
   reconciled: number;
+  recovered: number;
   cleanupStamped: number;
   pruned: number;
 };
@@ -250,6 +252,9 @@ export function reconcileTaskLookupToken(token: string): TaskRecord | undefined
   return task ? reconcileTaskRecordForOperatorInspection(task) : undefined;
 }
 
+// Preview is synchronous and cannot call the async detached-task recovery hook,
+// so recovered tasks are counted under reconciled here. The real sweep
+// in runTaskRegistryMaintenance splits them into reconciled vs recovered.
 export function previewTaskRegistryMaintenance(): TaskRegistryMaintenanceSummary {
   taskRegistryMaintenanceRuntime.ensureTaskRegistryReady();
   const now = Date.now();
@@ -269,7 +274,7 @@ export function previewTaskRegistryMaintenance(): TaskRegistryMaintenanceSummary
       cleanupStamped += 1;
     }
   }
-  return { reconciled, cleanupStamped, pruned };
+  return { reconciled, recovered: 0, cleanupStamped, pruned };
 }
 
 /**
@@ -296,6 +301,7 @@ export async function runTaskRegistryMaintenance(): Promise<TaskRegistryMaintena
   taskRegistryMaintenanceRuntime.ensureTaskRegistryReady();
   const now = Date.now();
   let reconciled = 0;
+  let recovered = 0;
   let cleanupStamped = 0;
   let pruned = 0;
   const tasks = taskRegistryMaintenanceRuntime.listTaskRecords();
@@ -306,7 +312,29 @@ export async function runTaskRegistryMaintenance(): Promise<TaskRegistryMaintena
       continue;
     }
     if (shouldMarkLost(current, now)) {
-      const next = markTaskLost(current, now);
+      const recovery = await tryRecoverTaskBeforeMarkLost({
+        taskId: current.taskId,
+        runtime: current.runtime,
+        task: current,
+        now,
+      });
+      const freshAfterHook = taskRegistryMaintenanceRuntime.getTaskById(current.taskId);
+      if (!freshAfterHook || !shouldMarkLost(freshAfterHook, now)) {
+        processed += 1;
+        if (processed % SWEEP_YIELD_BATCH_SIZE === 0) {
+          await yieldToEventLoop();
+        }
+        continue;
+      }
+      if (recovery.recovered) {
+        recovered += 1;
+        processed += 1;
+        if (processed % SWEEP_YIELD_BATCH_SIZE === 0) {
+          await yieldToEventLoop();
+        }
+        continue;
+      }
+      const next = markTaskLost(freshAfterHook, now);
       if (next.status === "lost") {
         reconciled += 1;
       }
@@ -341,7 +369,7 @@ export async function runTaskRegistryMaintenance(): Promise<TaskRegistryMaintena
       await yieldToEventLoop();
     }
   }
-  return { reconciled, cleanupStamped, pruned };
+  return { reconciled, recovered, cleanupStamped, pruned };
 }
 
 export async function sweepTaskRegistry(): Promise<TaskRegistryMaintenanceSummary> {
diff --git a/src/tasks/task-registry.test.ts b/src/tasks/task-registry.test.ts
index c575b00668e..28c44ff2907 100644
--- a/src/tasks/task-registry.test.ts
+++ b/src/tasks/task-registry.test.ts
@@ -1328,6 +1328,7 @@ describe("task-registry", () => {
 
       expect(await runTaskRegistryMaintenance()).toEqual({
         reconciled: 1,
+        recovered: 0,
         cleanupStamped: 0,
         pruned: 0,
       });
@@ -1363,6 +1364,7 @@ describe("task-registry", () => {
 
       expect(await sweepTaskRegistry()).toEqual({
         reconciled: 0,
+        recovered: 0,
         cleanupStamped: 0,
         pruned: 1,
       });
@@ -1406,12 +1408,14 @@ describe("task-registry", () => {
 
       expect(previewTaskRegistryMaintenance()).toEqual({
         reconciled: 0,
+        recovered: 0,
         cleanupStamped: 1,
         pruned: 0,
       });
 
       expect(await runTaskRegistryMaintenance()).toEqual({
         reconciled: 0,
+        recovered: 0,
         cleanupStamped: 1,
         pruned: 0,
       });
@@ -1530,6 +1534,7 @@ describe("task-registry", () => {
 
     expect(await runTaskRegistryMaintenance()).toEqual({
       reconciled: 0,
+      recovered: 0,
       cleanupStamped: 0,
       pruned: 0,
     });
@@ -1570,6 +1575,7 @@ describe("task-registry", () => {
 
     expect(await sweepTaskRegistry()).toEqual({
       reconciled: 0,
+      recovered: 0,
       cleanupStamped: 0,
       pruned: 0,
     });