diff --git a/CHANGELOG.md b/CHANGELOG.md
index b8f220718..9a6cf6ebb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -49,6 +49,7 @@ Docs: https://docs.openclaw.ai
 - Browser/Chrome extension handshake: bind relay WS message handling before `onopen` and add non-blocking `connect.challenge` response handling for gateway-style handshake frames, avoiding stuck `…` badge states when challenge frames arrive immediately on connect. Landed from contributor PR #22571 by @pandego. (#22553)
 - Browser/Extension relay init: dedupe concurrent same-port relay startup with shared in-flight initialization promises so callers await one startup lifecycle and receive consistent success/failure results. Landed from contributor PR #21277 by @HOYALIM. (Related #20688)
 - Browser/Extension relay shutdown: flush pending extension-request timers/rejections during relay `stop()` before socket/server teardown so in-flight extension waits do not survive shutdown windows. Landed from contributor PR #24142 by @kevinWangSheng.
+- Browser/Extension relay reconnect resilience: keep CDP clients alive across brief MV3 extension disconnect windows, wait briefly for extension reconnect before failing in-flight CDP commands, and only tear down relay target/client state after reconnect grace expires. Landed from contributor PR #27617 by @davidemanuelDEV.
 - Browser/Route decode hardening: guard malformed percent-encoding in relay target action routes and browser route-param decoding so crafted `%` paths return `400` instead of crashing/unhandled URI decode failures. Landed from contributor PR #11880 by @Yida-Dev.
 - Feishu/Permission error dispatch: merge sender-name permission notices into the main inbound dispatch so one user message produces one agent turn/reply (instead of a duplicate permission-notice turn), with regression coverage. (#27381) thanks @byungsker.
 - Feishu/Inbound message metadata: include inbound `message_id` in `BodyForAgent` on a dedicated metadata line so agents can reliably correlate and act on media/message operations that require message IDs, with regression coverage. (#27253) thanks @xss925175263.
diff --git a/src/browser/extension-relay.test.ts b/src/browser/extension-relay.test.ts
index 75b030923..8725c3f33 100644
--- a/src/browser/extension-relay.test.ts
+++ b/src/browser/extension-relay.test.ts
@@ -27,6 +27,22 @@ function waitForError(ws: WebSocket) {
   });
 }
 
+function waitForClose(ws: WebSocket, timeoutMs = RELAY_MESSAGE_TIMEOUT_MS) {
+  return new Promise<void>((resolve, reject) => {
+    const timer = setTimeout(() => {
+      reject(new Error("timeout"));
+    }, timeoutMs);
+    ws.once("close", () => {
+      clearTimeout(timer);
+      resolve();
+    });
+    ws.once("error", (err) => {
+      clearTimeout(timer);
+      reject(err instanceof Error ? err : new Error(String(err)));
+    });
+  });
+}
+
 function relayAuthHeaders(url: string) {
   return getChromeExtensionRelayAuthHeaders(url);
 }
@@ -132,8 +148,14 @@ describe("chrome extension relay server", () => {
   let envSnapshot: ReturnType<typeof captureEnv>;
 
   beforeEach(() => {
-    envSnapshot = captureEnv(["OPENCLAW_GATEWAY_TOKEN"]);
+    envSnapshot = captureEnv([
+      "OPENCLAW_GATEWAY_TOKEN",
+      "OPENCLAW_EXTENSION_RELAY_RECONNECT_GRACE_MS",
+      "OPENCLAW_EXTENSION_RELAY_COMMAND_RECONNECT_WAIT_MS",
+    ]);
     process.env.OPENCLAW_GATEWAY_TOKEN = TEST_GATEWAY_TOKEN;
+    delete process.env.OPENCLAW_EXTENSION_RELAY_RECONNECT_GRACE_MS;
+    delete process.env.OPENCLAW_EXTENSION_RELAY_COMMAND_RECONNECT_WAIT_MS;
   });
 
   afterEach(async () => {
@@ -341,6 +363,97 @@ describe("chrome extension relay server", () => {
     ext2.close();
   });
 
+  it("keeps CDP clients alive across a brief extension reconnect", async () => {
+    const { port, ext: ext1 } = await startRelayWithExtension();
+    const cdp = new WebSocket(`ws://127.0.0.1:${port}/cdp`, {
+      headers: relayAuthHeaders(`ws://127.0.0.1:${port}/cdp`),
+    });
+    await waitForOpen(cdp);
+
+    let cdpClosed = false;
+    cdp.once("close", () => {
+      cdpClosed = true;
+    });
+
+    const ext1Closed = waitForClose(ext1, 2_000);
+    ext1.close();
+    await ext1Closed;
+
+    await new Promise((r) => setTimeout(r, 200));
+    const ext2 = new WebSocket(`ws://127.0.0.1:${port}/extension`, {
+      headers: relayAuthHeaders(`ws://127.0.0.1:${port}/extension`),
+    });
+    await waitForOpen(ext2);
+
+    await new Promise((r) => setTimeout(r, 200));
+    expect(cdpClosed).toBe(false);
+
+    cdp.close();
+    ext2.close();
+  });
+
+  it("waits briefly for extension reconnect before failing CDP commands", async () => {
+    const { port, ext: ext1 } = await startRelayWithExtension();
+    const cdp = new WebSocket(`ws://127.0.0.1:${port}/cdp`, {
+      headers: relayAuthHeaders(`ws://127.0.0.1:${port}/cdp`),
+    });
+    await waitForOpen(cdp);
+    const cdpQueue = createMessageQueue(cdp);
+
+    const ext1Closed = waitForClose(ext1, 2_000);
+    ext1.close();
+    await ext1Closed;
+
+    cdp.send(JSON.stringify({ id: 41, method: "Runtime.enable" }));
+    await new Promise((r) => setTimeout(r, 150));
+
+    const ext2 = new WebSocket(`ws://127.0.0.1:${port}/extension`, {
+      headers: relayAuthHeaders(`ws://127.0.0.1:${port}/extension`),
+    });
+    const ext2Queue = createMessageQueue(ext2);
+    await waitForOpen(ext2);
+
+    while (true) {
+      const msg = JSON.parse(await ext2Queue.next(4_000)) as {
+        id?: number;
+        method?: string;
+      };
+      if (msg.method === "ping") {
+        ext2.send(JSON.stringify({ method: "pong" }));
+        continue;
+      }
+      if (msg.method === "forwardCDPCommand" && typeof msg.id === "number") {
+        ext2.send(JSON.stringify({ id: msg.id, result: { ok: true } }));
+        break;
+      }
+    }
+
+    const response = JSON.parse(await cdpQueue.next(6_000)) as {
+      id?: number;
+      result?: { ok?: boolean };
+      error?: { message?: string };
+    };
+    expect(response.id).toBe(41);
+    expect(response.error).toBeUndefined();
+    expect(response.result?.ok).toBe(true);
+
+    cdp.close();
+    ext2.close();
+  });
+
+  it("closes CDP clients after reconnect grace when extension stays disconnected", async () => {
+    process.env.OPENCLAW_EXTENSION_RELAY_RECONNECT_GRACE_MS = "150";
+
+    const { port, ext } = await startRelayWithExtension();
+    const cdp = new WebSocket(`ws://127.0.0.1:${port}/cdp`, {
+      headers: relayAuthHeaders(`ws://127.0.0.1:${port}/cdp`),
+    });
+    await waitForOpen(cdp);
+
+    ext.close();
+    await waitForClose(cdp, 2_000);
+  });
+
   it("accepts extension websocket access with relay token query param", async () => {
     const port = await getFreePort();
     cdpUrl = `http://127.0.0.1:${port}`;
diff --git a/src/browser/extension-relay.ts b/src/browser/extension-relay.ts
index 0e430c2b2..3f5697f1d 100644
--- a/src/browser/extension-relay.ts
+++ b/src/browser/extension-relay.ts
@@ -82,6 +82,8 @@ type ConnectedTarget = {
 };
 
 const RELAY_AUTH_HEADER = "x-openclaw-relay-token";
+const DEFAULT_EXTENSION_RECONNECT_GRACE_MS = 5_000;
+const DEFAULT_EXTENSION_COMMAND_RECONNECT_WAIT_MS = 3_000;
 
 function headerValue(value: string | string[] | undefined): string | undefined {
   if (!value) {
@@ -171,6 +173,18 @@ function rejectUpgrade(socket: Duplex, status: number, bodyText: string) {
   }
 }
 
+function envMsOrDefault(name: string, fallback: number): number {
+  const raw = process.env[name];
+  if (!raw || raw.trim() === "") {
+    return fallback;
+  }
+  const parsed = Number.parseInt(raw, 10);
+  if (!Number.isFinite(parsed) || parsed <= 0) {
+    return fallback;
+  }
+  return parsed;
+}
+
 const relayRuntimeByPort = new Map<number, RelayRuntime>();
 const relayInitByPort = new Map<number, Promise<ChromeExtensionRelayServer>>();
 
@@ -225,6 +239,15 @@ export async function ensureChromeExtensionRelayServer(opts: {
     return await inFlight;
   }
 
+  const extensionReconnectGraceMs = envMsOrDefault(
+    "OPENCLAW_EXTENSION_RELAY_RECONNECT_GRACE_MS",
+    DEFAULT_EXTENSION_RECONNECT_GRACE_MS,
+  );
+  const extensionCommandReconnectWaitMs = envMsOrDefault(
+    "OPENCLAW_EXTENSION_RELAY_COMMAND_RECONNECT_WAIT_MS",
+    DEFAULT_EXTENSION_COMMAND_RECONNECT_WAIT_MS,
+  );
+
   const initPromise = (async (): Promise<ChromeExtensionRelayServer> => {
     const relayAuthToken = resolveRelayAuthTokenForPort(info.port);
     const relayAuthTokens = new Set(resolveRelayAcceptedTokensForPort(info.port));
@@ -233,6 +256,73 @@ export async function ensureChromeExtensionRelayServer(opts: {
     const cdpClients = new Set<WebSocket>();
     const connectedTargets = new Map<string, ConnectedTarget>();
     const extensionConnected = () => extensionWs?.readyState === WebSocket.OPEN;
+    let extensionDisconnectCleanupTimer: NodeJS.Timeout | null = null;
+    const extensionReconnectWaiters = new Set<(connected: boolean) => void>();
+
+    const flushExtensionReconnectWaiters = (connected: boolean) => {
+      if (extensionReconnectWaiters.size === 0) {
+        return;
+      }
+      const waiters = Array.from(extensionReconnectWaiters);
+      extensionReconnectWaiters.clear();
+      for (const waiter of waiters) {
+        waiter(connected);
+      }
+    };
+
+    const clearExtensionDisconnectCleanupTimer = () => {
+      if (!extensionDisconnectCleanupTimer) {
+        return;
+      }
+      clearTimeout(extensionDisconnectCleanupTimer);
+      extensionDisconnectCleanupTimer = null;
+    };
+
+    const closeCdpClientsAfterExtensionDisconnect = () => {
+      connectedTargets.clear();
+      for (const client of cdpClients) {
+        try {
+          client.close(1011, "extension disconnected");
+        } catch {
+          // ignore
+        }
+      }
+      cdpClients.clear();
+      flushExtensionReconnectWaiters(false);
+    };
+
+    const scheduleExtensionDisconnectCleanup = () => {
+      clearExtensionDisconnectCleanupTimer();
+      extensionDisconnectCleanupTimer = setTimeout(() => {
+        extensionDisconnectCleanupTimer = null;
+        if (extensionConnected()) {
+          return;
+        }
+        closeCdpClientsAfterExtensionDisconnect();
+      }, extensionReconnectGraceMs);
+    };
+
+    const waitForExtensionReconnect = async (timeoutMs: number): Promise<boolean> => {
+      if (extensionConnected()) {
+        return true;
+      }
+      return await new Promise<boolean>((resolve) => {
+        let settled = false;
+        const waiter = (connected: boolean) => {
+          if (settled) {
+            return;
+          }
+          settled = true;
+          clearTimeout(timer);
+          extensionReconnectWaiters.delete(waiter);
+          resolve(connected);
+        };
+        const timer = setTimeout(() => {
+          waiter(false);
+        }, timeoutMs);
+        extensionReconnectWaiters.add(waiter);
+      });
+    };
 
     const pendingExtension = new Map<
       number,
@@ -543,10 +633,6 @@ export async function ensureChromeExtensionRelayServer(opts: {
           rejectUpgrade(socket, 401, "Unauthorized");
           return;
         }
-        if (extensionConnected()) {
-          rejectUpgrade(socket, 409, "Extension already connected");
-          return;
-        }
         // MV3 worker reconnect races can leave a stale non-OPEN socket reference.
         if (extensionWs && extensionWs.readyState !== WebSocket.OPEN) {
           try {
@@ -556,6 +642,10 @@ export async function ensureChromeExtensionRelayServer(opts: {
           }
           extensionWs = null;
         }
+        if (extensionConnected()) {
+          rejectUpgrade(socket, 409, "Extension already connected");
+          return;
+        }
         wssExtension.handleUpgrade(req, socket, head, (ws) => {
           wssExtension.emit("connection", ws, req);
         });
@@ -583,6 +673,8 @@ export async function ensureChromeExtensionRelayServer(opts: {
 
     wssExtension.on("connection", (ws) => {
       extensionWs = ws;
+      clearExtensionDisconnectCleanupTimer();
+      flushExtensionReconnectWaiters(true);
 
       const ping = setInterval(() => {
         if (ws.readyState !== WebSocket.OPEN) {
@@ -710,16 +802,7 @@ export async function ensureChromeExtensionRelayServer(opts: {
           pending.reject(new Error("extension disconnected"));
         }
         pendingExtension.clear();
-        connectedTargets.clear();
-
-        for (const client of cdpClients) {
-          try {
-            client.close(1011, "extension disconnected");
-          } catch {
-            // ignore
-          }
-        }
-        cdpClients.clear();
+        scheduleExtensionDisconnectCleanup();
       });
     });
 
@@ -741,12 +824,15 @@ export async function ensureChromeExtensionRelayServer(opts: {
         }
 
         if (!extensionConnected()) {
-          sendResponseToCdp(ws, {
-            id: cmd.id,
-            sessionId: cmd.sessionId,
-            error: { message: "Extension not connected" },
-          });
-          return;
+          const reconnected = await waitForExtensionReconnect(extensionCommandReconnectWaitMs);
+          if (!reconnected || !extensionConnected()) {
+            sendResponseToCdp(ws, {
+              id: cmd.id,
+              sessionId: cmd.sessionId,
+              error: { message: "Extension not connected" },
+            });
+            return;
+          }
         }
 
         try {
@@ -841,6 +927,8 @@ export async function ensureChromeExtensionRelayServer(opts: {
       extensionConnected,
       stop: async () => {
         relayRuntimeByPort.delete(port);
+        clearExtensionDisconnectCleanupTimer();
+        flushExtensionReconnectWaiters(false);
         for (const [, pending] of pendingExtension) {
           clearTimeout(pending.timer);
           pending.reject(new Error("server stopping"));