diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4bfbe123ff7..843436f473e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -38,6 +38,7 @@ Docs: https://docs.openclaw.ai
 
 ### Fixes
 
+- Browser/Extension startup: stop failing browser startup when relay is reachable but no tab is attached yet; tab attachment is now required only when a tab action actually runs. (#28855) Thanks @Sid-Qin.
 - Browser/Remote CDP ownership checks: skip local-process ownership errors for non-loopback remote CDP profiles when HTTP is reachable but the websocket handshake fails, and surface the remote websocket attach/retry path instead. (#15582) Landed from contributor (#28780) Thanks @stubbi, @bsormagec, @unblockedgamesstudio and @vincentkoc.
 - Docker/Image health checks: add Dockerfile `HEALTHCHECK` that probes gateway `GET /healthz` so container runtimes can mark unhealthy instances without requiring auth credentials in the probe command. (#11478) Thanks @U-C4N and @vincentkoc.
 - Daemon/systemd checks in containers: treat missing `systemctl` invocations (including `spawn systemctl ENOENT`/`EACCES`) as unavailable service state during `is-enabled` checks, preventing container flows from failing with `Gateway service check failed` before install/status handling can continue. (#26089) Thanks @sahilsatralkar and @vincentkoc.
diff --git a/src/browser/server-context.ensure-tab-available.prefers-last-target.test.ts b/src/browser/server-context.ensure-tab-available.prefers-last-target.test.ts
index b3f15680def..2dc00cf5292 100644
--- a/src/browser/server-context.ensure-tab-available.prefers-last-target.test.ts
+++ b/src/browser/server-context.ensure-tab-available.prefers-last-target.test.ts
@@ -1,5 +1,7 @@
 import { describe, expect, it, vi } from "vitest";
 import { withFetchPreconnect } from "../test-utils/fetch-mock.js";
+import * as chromeModule from "./chrome.js";
+import * as extensionRelayModule from "./extension-relay.js";
 import type { BrowserServerState } from "./server-context.js";
 import "./server-context.chrome-test-harness.js";
 import { createBrowserRouteContext } from "./server-context.js";
@@ -120,4 +122,21 @@ describe("browser server-context ensureTabAvailable", () => {
     const chrome = ctx.forProfile("chrome");
     await expect(chrome.ensureTabAvailable()).rejects.toThrow(/no attached Chrome tabs/i);
   });
+
+  it("starts relay without requiring an attached tab during browser availability checks", async () => {
+    const isChromeReachableMock = vi.mocked(chromeModule.isChromeReachable);
+    const ensureRelaySpy = vi
+      .spyOn(extensionRelayModule, "ensureChromeExtensionRelayServer")
+      .mockResolvedValue(undefined as never);
+    isChromeReachableMock.mockResolvedValueOnce(false).mockResolvedValueOnce(true);
+
+    const state = makeBrowserState();
+    const ctx = createBrowserRouteContext({ getState: () => state });
+    const chrome = ctx.forProfile("chrome");
+
+    await expect(chrome.ensureBrowserAvailable()).resolves.toBeUndefined();
+    expect(ensureRelaySpy).toHaveBeenCalledWith({ cdpUrl: "http://127.0.0.1:18792" });
+
+    ensureRelaySpy.mockRestore();
+  });
 });