diff --git a/extensions/whatsapp/src/auto-reply/monitor-state.test.ts b/extensions/whatsapp/src/auto-reply/monitor-state.test.ts
new file mode 100644
index 00000000000..c0e0c218cf5
--- /dev/null
+++ b/extensions/whatsapp/src/auto-reply/monitor-state.test.ts
@@ -0,0 +1,53 @@
+import { describe, expect, it } from "vitest";
+import { createWebChannelStatusController } from "./monitor-state.js";
+
+describe("createWebChannelStatusController", () => {
+  it("sets lastTransportActivityAt on noteConnected", () => {
+    const patches: Record<string, unknown>[] = [];
+    const controller = createWebChannelStatusController((s) => patches.push({ ...s }));
+
+    controller.noteConnected(1000);
+
+    const last = patches.at(-1)!;
+    expect(last.connected).toBe(true);
+    expect(last.lastTransportActivityAt).toBe(1000);
+  });
+
+  it("updates lastTransportActivityAt on noteInbound", () => {
+    const patches: Record<string, unknown>[] = [];
+    const controller = createWebChannelStatusController((s) => patches.push({ ...s }));
+
+    controller.noteConnected(1000);
+    controller.noteInbound(2000);
+
+    const last = patches.at(-1)!;
+    expect(last.lastTransportActivityAt).toBe(2000);
+  });
+
+  it("does not set lastTransportActivityAt on noteWatchdogStale", () => {
+    const patches: Record<string, unknown>[] = [];
+    const controller = createWebChannelStatusController((s) => patches.push({ ...s }));
+
+    controller.noteConnected(1000);
+    controller.noteWatchdogStale(5000);
+
+    const last = patches.at(-1)!;
+    // Watchdog staleness should not refresh transport activity — it means
+    // the check loop is running but the socket itself is idle/stale.
+    expect(last.lastTransportActivityAt).toBe(1000);
+  });
+
+  it("produces snapshots that enable stale-socket health detection", () => {
+    const patches: Record<string, unknown>[] = [];
+    const controller = createWebChannelStatusController((s) => patches.push({ ...s }));
+
+    controller.noteConnected(1000);
+
+    const last = patches.at(-1)!;
+    // The gateway health policy checks `connected === true && lastTransportActivityAt != null`
+    // to decide whether to run stale-socket detection. Both must be present.
+    expect(last.connected).toBe(true);
+    expect(last.lastTransportActivityAt).not.toBeNull();
+    expect(typeof last.lastTransportActivityAt).toBe("number");
+  });
+});
diff --git a/extensions/whatsapp/src/auto-reply/monitor-state.ts b/extensions/whatsapp/src/auto-reply/monitor-state.ts
index b03ed80f39b..77de22dd930 100644
--- a/extensions/whatsapp/src/auto-reply/monitor-state.ts
+++ b/extensions/whatsapp/src/auto-reply/monitor-state.ts
@@ -1,4 +1,7 @@
-import { createConnectedChannelStatusPatch } from "openclaw/plugin-sdk/gateway-runtime";
+import {
+  createConnectedChannelStatusPatch,
+  createTransportActivityStatusPatch,
+} from "openclaw/plugin-sdk/gateway-runtime";
 import type { WebChannelHealthState, WebChannelStatus } from "./types.js";
 
 function cloneStatus(status: WebChannelStatus): WebChannelStatus {
@@ -35,6 +38,7 @@ export function createWebChannelStatusController(statusSink?: (status: WebChanne
     snapshot: () => status,
     noteConnected(at = Date.now()) {
       Object.assign(status, createConnectedChannelStatusPatch(at));
+      Object.assign(status, createTransportActivityStatusPatch(at));
       status.lastError = null;
       status.healthState = "healthy";
       emit();
@@ -43,6 +47,7 @@ export function createWebChannelStatusController(statusSink?: (status: WebChanne
       status.lastInboundAt = at;
       status.lastMessageAt = at;
       status.lastEventAt = at;
+      Object.assign(status, createTransportActivityStatusPatch(at));
       if (status.connected) {
         status.healthState = "healthy";
       }
diff --git a/extensions/whatsapp/src/auto-reply/types.ts b/extensions/whatsapp/src/auto-reply/types.ts
index 68c3ee545f6..5479b619d48 100644
--- a/extensions/whatsapp/src/auto-reply/types.ts
+++ b/extensions/whatsapp/src/auto-reply/types.ts
@@ -27,6 +27,7 @@ export type WebChannelStatus = {
   lastInboundAt?: number | null;
   lastMessageAt?: number | null;
   lastEventAt?: number | null;
+  lastTransportActivityAt?: number | null;
   lastError?: string | null;
   healthState?: WebChannelHealthState;
 };