diff --git a/CHANGELOG.md b/CHANGELOG.md
index 675a9f9b5b..5015c07d07 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@ Docs: https://docs.openclaw.ai
 
 ### Fixes
 
+- Agents: add a safety timeout around embedded `session.compact()` to ensure stalled compaction runs settle and release blocked session lanes. (#16331) Thanks @BinHPdev.
 - Agents: keep unresolved mutating tool failures visible until the same action retry succeeds, scope mutation-error surfacing to mutating calls (including `session_status` model changes), and dedupe duplicate failure warnings in outbound replies. (#16131) Thanks @Swader.
 - Agents: classify external timeout aborts during compaction the same as internal timeouts, preventing unnecessary auth-profile rotation and preserving compaction-timeout snapshot fallback behavior. (#9855) Thanks @mverrilli.
 - Sessions/Agents: harden transcript path resolution for mismatched agent context by preserving explicit store roots and adding safe absolute-path fallback to the correct agent sessions directory. (#16288) Thanks @robbyczgw-cla.
diff --git a/src/agents/pi-embedded-runner.compaction-safety-timeout.test.ts b/src/agents/pi-embedded-runner.compaction-safety-timeout.test.ts
new file mode 100644
index 0000000000..31906dd733
--- /dev/null
+++ b/src/agents/pi-embedded-runner.compaction-safety-timeout.test.ts
@@ -0,0 +1,45 @@
+import { afterEach, describe, expect, it, vi } from "vitest";
+import {
+  compactWithSafetyTimeout,
+  EMBEDDED_COMPACTION_TIMEOUT_MS,
+} from "./pi-embedded-runner/compaction-safety-timeout.js";
+
+describe("compactWithSafetyTimeout", () => {
+  afterEach(() => {
+    vi.useRealTimers();
+  });
+
+  it("rejects with timeout when compaction never settles", async () => {
+    vi.useFakeTimers();
+    const compactPromise = compactWithSafetyTimeout(() => new Promise<never>(() => {}));
+    const timeoutAssertion = expect(compactPromise).rejects.toThrow("Compaction timed out");
+
+    await vi.advanceTimersByTimeAsync(EMBEDDED_COMPACTION_TIMEOUT_MS);
+    await timeoutAssertion;
+    expect(vi.getTimerCount()).toBe(0);
+  });
+
+  it("returns result and clears timer when compaction settles first", async () => {
+    vi.useFakeTimers();
+    const compactPromise = compactWithSafetyTimeout(
+      () => new Promise<string>((resolve) => setTimeout(() => resolve("ok"), 10)),
+      30,
+    );
+
+    await vi.advanceTimersByTimeAsync(10);
+    await expect(compactPromise).resolves.toBe("ok");
+    expect(vi.getTimerCount()).toBe(0);
+  });
+
+  it("preserves compaction errors and clears timer", async () => {
+    vi.useFakeTimers();
+    const error = new Error("provider exploded");
+
+    await expect(
+      compactWithSafetyTimeout(async () => {
+        throw error;
+      }, 30),
+    ).rejects.toBe(error);
+    expect(vi.getTimerCount()).toBe(0);
+  });
+});
diff --git a/src/agents/pi-embedded-runner/compact.ts b/src/agents/pi-embedded-runner/compact.ts
index 1ada5c626a..6a100bd84a 100644
--- a/src/agents/pi-embedded-runner/compact.ts
+++ b/src/agents/pi-embedded-runner/compact.ts
@@ -57,6 +57,7 @@ import {
   type SkillSnapshot,
 } from "../skills.js";
 import { resolveTranscriptPolicy } from "../transcript-policy.js";
+import { compactWithSafetyTimeout } from "./compaction-safety-timeout.js";
 import { buildEmbeddedExtensionPaths } from "./extensions.js";
 import {
   logToolSchemasForGoogle,
@@ -107,7 +108,7 @@ export type CompactEmbeddedPiSessionParams = {
   reasoningLevel?: ReasoningLevel;
   bashElevated?: ExecElevatedDefaults;
   customInstructions?: string;
-  trigger?: "overflow" | "manual" | "cache_ttl" | "safeguard";
+  trigger?: "overflow" | "manual";
   diagId?: string;
   attempt?: number;
   maxAttempts?: number;
@@ -632,7 +633,9 @@ export async function compactEmbeddedPiSessionDirect(
         }
 
         const compactStartedAt = Date.now();
-        const result = await session.compact(params.customInstructions);
+        const result = await compactWithSafetyTimeout(() =>
+          session.compact(params.customInstructions),
+        );
         // Estimate tokens after compaction by summing token estimates for remaining messages
         let tokensAfter: number | undefined;
         try {
diff --git a/src/agents/pi-embedded-runner/compaction-safety-timeout.ts b/src/agents/pi-embedded-runner/compaction-safety-timeout.ts
new file mode 100644
index 0000000000..689aa9a931
--- /dev/null
+++ b/src/agents/pi-embedded-runner/compaction-safety-timeout.ts
@@ -0,0 +1,10 @@
+import { withTimeout } from "../../node-host/with-timeout.js";
+
+export const EMBEDDED_COMPACTION_TIMEOUT_MS = 300_000;
+
+export async function compactWithSafetyTimeout<T>(
+  compact: () => Promise<T>,
+  timeoutMs: number = EMBEDDED_COMPACTION_TIMEOUT_MS,
+): Promise<T> {
+  return await withTimeout(() => compact(), timeoutMs, "Compaction");
+}
diff --git a/src/agents/pi-embedded-runner/run.overflow-compaction.test.ts b/src/agents/pi-embedded-runner/run.overflow-compaction.test.ts
new file mode 100644
index 0000000000..1a2c297917
--- /dev/null
+++ b/src/agents/pi-embedded-runner/run.overflow-compaction.test.ts
@@ -0,0 +1,240 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+
+vi.mock("./run/attempt.js", () => ({
+  runEmbeddedAttempt: vi.fn(),
+}));
+
+vi.mock("./compact.js", () => ({
+  compactEmbeddedPiSessionDirect: vi.fn(),
+}));
+
+vi.mock("./model.js", () => ({
+  resolveModel: vi.fn(() => ({
+    model: {
+      id: "test-model",
+      provider: "anthropic",
+      contextWindow: 200000,
+      api: "messages",
+    },
+    error: null,
+    authStorage: {
+      setRuntimeApiKey: vi.fn(),
+    },
+    modelRegistry: {},
+  })),
+}));
+
+vi.mock("../model-auth.js", () => ({
+  ensureAuthProfileStore: vi.fn(() => ({})),
+  getApiKeyForModel: vi.fn(async () => ({
+    apiKey: "test-key",
+    profileId: "test-profile",
+    source: "test",
+  })),
+  resolveAuthProfileOrder: vi.fn(() => []),
+}));
+
+vi.mock("../models-config.js", () => ({
+  ensureOpenClawModelsJson: vi.fn(async () => {}),
+}));
+
+vi.mock("../context-window-guard.js", () => ({
+  CONTEXT_WINDOW_HARD_MIN_TOKENS: 1000,
+  CONTEXT_WINDOW_WARN_BELOW_TOKENS: 5000,
+  evaluateContextWindowGuard: vi.fn(() => ({
+    shouldWarn: false,
+    shouldBlock: false,
+    tokens: 200000,
+    source: "model",
+  })),
+  resolveContextWindowInfo: vi.fn(() => ({
+    tokens: 200000,
+    source: "model",
+  })),
+}));
+
+vi.mock("../../process/command-queue.js", () => ({
+  enqueueCommandInLane: vi.fn((_lane: string, task: () => unknown) => task()),
+}));
+
+vi.mock("../../utils/message-channel.js", () => ({
+  isMarkdownCapableMessageChannel: vi.fn(() => true),
+}));
+
+vi.mock("../agent-paths.js", () => ({
+  resolveOpenClawAgentDir: vi.fn(() => "/tmp/agent-dir"),
+}));
+
+vi.mock("../auth-profiles.js", () => ({
+  isProfileInCooldown: vi.fn(() => false),
+  markAuthProfileFailure: vi.fn(async () => {}),
+  markAuthProfileGood: vi.fn(async () => {}),
+  markAuthProfileUsed: vi.fn(async () => {}),
+}));
+
+vi.mock("../defaults.js", () => ({
+  DEFAULT_CONTEXT_TOKENS: 200000,
+  DEFAULT_MODEL: "test-model",
+  DEFAULT_PROVIDER: "anthropic",
+}));
+
+vi.mock("../failover-error.js", () => ({
+  FailoverError: class extends Error {},
+  resolveFailoverStatus: vi.fn(),
+}));
+
+vi.mock("../usage.js", () => ({
+  normalizeUsage: vi.fn((usage?: unknown) =>
+    usage && typeof usage === "object" ? usage : undefined,
+  ),
+  derivePromptTokens: vi.fn(
+    (usage?: { input?: number; cacheRead?: number; cacheWrite?: number }) => {
+      if (!usage) {
+        return undefined;
+      }
+      const input = usage.input ?? 0;
+      const cacheRead = usage.cacheRead ?? 0;
+      const cacheWrite = usage.cacheWrite ?? 0;
+      const sum = input + cacheRead + cacheWrite;
+      return sum > 0 ? sum : undefined;
+    },
+  ),
+}));
+
+vi.mock("../workspace-run.js", () => ({
+  resolveRunWorkspaceDir: vi.fn((params: { workspaceDir: string }) => ({
+    workspaceDir: params.workspaceDir,
+    usedFallback: false,
+    fallbackReason: undefined,
+    agentId: "main",
+  })),
+  redactRunIdentifier: vi.fn((value?: string) => value ?? ""),
+}));
+
+vi.mock("./lanes.js", () => ({
+  resolveSessionLane: vi.fn(() => "session-lane"),
+  resolveGlobalLane: vi.fn(() => "global-lane"),
+}));
+
+vi.mock("./logger.js", () => ({
+  log: {
+    debug: vi.fn(),
+    info: vi.fn(),
+    warn: vi.fn(),
+    error: vi.fn(),
+    isEnabled: vi.fn(() => false),
+  },
+}));
+
+vi.mock("./run/payloads.js", () => ({
+  buildEmbeddedRunPayloads: vi.fn(() => []),
+}));
+
+vi.mock("./tool-result-truncation.js", () => ({
+  truncateOversizedToolResultsInSession: vi.fn(async () => ({
+    truncated: false,
+    truncatedCount: 0,
+    reason: "no oversized tool results",
+  })),
+  sessionLikelyHasOversizedToolResults: vi.fn(() => false),
+}));
+
+vi.mock("./utils.js", () => ({
+  describeUnknownError: vi.fn((err: unknown) => {
+    if (err instanceof Error) {
+      return err.message;
+    }
+    return String(err);
+  }),
+}));
+
+vi.mock("../pi-embedded-helpers.js", () => ({
+  formatBillingErrorMessage: vi.fn(() => ""),
+  classifyFailoverReason: vi.fn(() => null),
+  formatAssistantErrorText: vi.fn(() => ""),
+  isAuthAssistantError: vi.fn(() => false),
+  isBillingAssistantError: vi.fn(() => false),
+  isCompactionFailureError: vi.fn(() => false),
+  isLikelyContextOverflowError: vi.fn((msg?: string) => {
+    const lower = (msg ?? "").toLowerCase();
+    return lower.includes("request_too_large") || lower.includes("context window exceeded");
+  }),
+  isFailoverAssistantError: vi.fn(() => false),
+  isFailoverErrorMessage: vi.fn(() => false),
+  parseImageSizeError: vi.fn(() => null),
+  parseImageDimensionError: vi.fn(() => null),
+  isRateLimitAssistantError: vi.fn(() => false),
+  isTimeoutErrorMessage: vi.fn(() => false),
+  pickFallbackThinkingLevel: vi.fn(() => null),
+}));
+
+import type { EmbeddedRunAttemptResult } from "./run/types.js";
+import { compactEmbeddedPiSessionDirect } from "./compact.js";
+import { runEmbeddedPiAgent } from "./run.js";
+import { runEmbeddedAttempt } from "./run/attempt.js";
+
+const mockedRunEmbeddedAttempt = vi.mocked(runEmbeddedAttempt);
+const mockedCompactDirect = vi.mocked(compactEmbeddedPiSessionDirect);
+
+function makeAttemptResult(
+  overrides: Partial<EmbeddedRunAttemptResult> = {},
+): EmbeddedRunAttemptResult {
+  return {
+    aborted: false,
+    timedOut: false,
+    timedOutDuringCompaction: false,
+    promptError: null,
+    sessionIdUsed: "test-session",
+    assistantTexts: ["Hello!"],
+    toolMetas: [],
+    lastAssistant: undefined,
+    messagesSnapshot: [],
+    didSendViaMessagingTool: false,
+    messagingToolSentTexts: [],
+    messagingToolSentTargets: [],
+    cloudCodeAssistFormatError: false,
+    ...overrides,
+  };
+}
+
+describe("runEmbeddedPiAgent overflow compaction trigger routing", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("passes trigger=overflow when retrying compaction after context overflow", async () => {
+    const overflowError = new Error("request_too_large: Request size exceeds model context window");
+
+    mockedRunEmbeddedAttempt
+      .mockResolvedValueOnce(makeAttemptResult({ promptError: overflowError }))
+      .mockResolvedValueOnce(makeAttemptResult({ promptError: null }));
+
+    mockedCompactDirect.mockResolvedValueOnce({
+      ok: true,
+      compacted: true,
+      result: {
+        summary: "Compacted session",
+        firstKeptEntryId: "entry-5",
+        tokensBefore: 150000,
+      },
+    });
+
+    await runEmbeddedPiAgent({
+      sessionId: "test-session",
+      sessionKey: "test-key",
+      sessionFile: "/tmp/session.json",
+      workspaceDir: "/tmp/workspace",
+      prompt: "hello",
+      timeoutMs: 30000,
+      runId: "run-1",
+    });
+
+    expect(mockedCompactDirect).toHaveBeenCalledTimes(1);
+    expect(mockedCompactDirect).toHaveBeenCalledWith(
+      expect.objectContaining({
+        trigger: "overflow",
+        authProfileId: "test-profile",
+      }),
+    );
+  });
+});
diff --git a/src/auto-reply/reply/commands-compact.test.ts b/src/auto-reply/reply/commands-compact.test.ts
new file mode 100644
index 0000000000..7c418ac239
--- /dev/null
+++ b/src/auto-reply/reply/commands-compact.test.ts
@@ -0,0 +1,114 @@
+import { beforeEach, describe, expect, it, vi } from "vitest";
+import type { OpenClawConfig } from "../../config/config.js";
+import { compactEmbeddedPiSession } from "../../agents/pi-embedded.js";
+import { handleCompactCommand } from "./commands-compact.js";
+import { buildCommandTestParams } from "./commands.test-harness.js";
+
+vi.mock("../../agents/pi-embedded.js", () => ({
+  abortEmbeddedPiRun: vi.fn(),
+  compactEmbeddedPiSession: vi.fn(),
+  isEmbeddedPiRunActive: vi.fn().mockReturnValue(false),
+  waitForEmbeddedPiRunEnd: vi.fn().mockResolvedValue(undefined),
+}));
+
+vi.mock("../../infra/system-events.js", () => ({
+  enqueueSystemEvent: vi.fn(),
+}));
+
+vi.mock("./session-updates.js", () => ({
+  incrementCompactionCount: vi.fn(),
+}));
+
+describe("/compact command", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("returns null when command is not /compact", async () => {
+    const cfg = {
+      commands: { text: true },
+      channels: { whatsapp: { allowFrom: ["*"] } },
+    } as OpenClawConfig;
+    const params = buildCommandTestParams("/status", cfg);
+
+    const result = await handleCompactCommand(
+      {
+        ...params,
+      },
+      true,
+    );
+
+    expect(result).toBeNull();
+    expect(vi.mocked(compactEmbeddedPiSession)).not.toHaveBeenCalled();
+  });
+
+  it("rejects unauthorized /compact commands", async () => {
+    const cfg = {
+      commands: { text: true },
+      channels: { whatsapp: { allowFrom: ["*"] } },
+    } as OpenClawConfig;
+    const params = buildCommandTestParams("/compact", cfg);
+
+    const result = await handleCompactCommand(
+      {
+        ...params,
+        command: {
+          ...params.command,
+          isAuthorizedSender: false,
+          senderId: "unauthorized",
+        },
+      },
+      true,
+    );
+
+    expect(result).toEqual({ shouldContinue: false });
+    expect(vi.mocked(compactEmbeddedPiSession)).not.toHaveBeenCalled();
+  });
+
+  it("routes manual compaction with explicit trigger and context metadata", async () => {
+    const cfg = {
+      commands: { text: true },
+      channels: { whatsapp: { allowFrom: ["*"] } },
+      session: { store: "/tmp/openclaw-session-store.json" },
+    } as OpenClawConfig;
+    const params = buildCommandTestParams("/compact: focus on decisions", cfg, {
+      From: "+15550001",
+      To: "+15550002",
+    });
+    vi.mocked(compactEmbeddedPiSession).mockResolvedValueOnce({
+      ok: true,
+      compacted: false,
+    });
+
+    const result = await handleCompactCommand(
+      {
+        ...params,
+        sessionEntry: {
+          sessionId: "session-1",
+          groupId: "group-1",
+          groupChannel: "#general",
+          space: "workspace-1",
+          spawnedBy: "agent:main:parent",
+          totalTokens: 12345,
+        },
+      },
+      true,
+    );
+
+    expect(result?.shouldContinue).toBe(false);
+    expect(vi.mocked(compactEmbeddedPiSession)).toHaveBeenCalledOnce();
+    expect(vi.mocked(compactEmbeddedPiSession)).toHaveBeenCalledWith(
+      expect.objectContaining({
+        sessionId: "session-1",
+        sessionKey: "agent:main:main",
+        trigger: "manual",
+        customInstructions: "focus on decisions",
+        messageChannel: "whatsapp",
+        groupId: "group-1",
+        groupChannel: "#general",
+        groupSpace: "workspace-1",
+        spawnedBy: "agent:main:parent",
+      }),
+    );
+  });
+});
diff --git a/src/auto-reply/reply/commands-compact.ts b/src/auto-reply/reply/commands-compact.ts
index 00b00e7ede..3362950872 100644
--- a/src/auto-reply/reply/commands-compact.ts
+++ b/src/auto-reply/reply/commands-compact.ts
@@ -103,6 +103,7 @@ export const handleCompactCommand: CommandHandler = async (params) => {
       defaultLevel: "off",
     },
     customInstructions,
+    trigger: "manual",
     senderIsOwner: params.command.senderIsOwner,
     ownerNumbers: params.command.ownerList.length > 0 ? params.command.ownerList : undefined,
   });
diff --git a/src/node-host/with-timeout.ts b/src/node-host/with-timeout.ts
index 07ea141549..1acf525a79 100644
--- a/src/node-host/with-timeout.ts
+++ b/src/node-host/with-timeout.ts
@@ -14,6 +14,7 @@ export async function withTimeout<T>(
   const abortCtrl = new AbortController();
   const timeoutError = new Error(`${label ?? "request"} timed out`);
   const timer = setTimeout(() => abortCtrl.abort(timeoutError), resolved);
+  timer.unref?.();
 
   let abortListener: (() => void) | undefined;
   const abortPromise: Promise<never> = abortCtrl.signal.aborted