diff --git a/src/hooks/gmail-watcher.test.ts b/src/hooks/gmail-watcher.test.ts
new file mode 100644
index 00000000000..873c47bff95
--- /dev/null
+++ b/src/hooks/gmail-watcher.test.ts
@@ -0,0 +1,123 @@
+import { EventEmitter } from "node:events";
+import type { ChildProcess } from "node:child_process";
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+const runtimeConfig = {
+  account: "clawdbot@gmail.com",
+  label: "INBOX",
+  topic: "projects/test/topics/gog-gmail-watch",
+  subscription: "gog-gmail-watch-push",
+  pushToken: "push-token",
+  hookToken: "hook-token",
+  hookUrl: "http://127.0.0.1:18789/hooks/gmail",
+  includeBody: false,
+  maxBytes: 0,
+  renewEveryMinutes: 720,
+  serve: { bind: "127.0.0.1", port: 8788, path: "/" },
+  tailscale: { mode: "off", path: "/gmail-pubsub" },
+};
+
+class MockChild extends EventEmitter {
+  stdout = new EventEmitter();
+  stderr = new EventEmitter();
+  exitCode: number | null = null;
+  kill = vi.fn();
+}
+
+const spawnMock = vi.fn(() => new MockChild() as unknown as ChildProcess);
+
+vi.mock("node:child_process", async () => {
+  const actual = await vi.importActual<typeof import("node:child_process")>(
+    "node:child_process",
+  );
+  return {
+    ...actual,
+    spawn: spawnMock,
+  };
+});
+
+const runCommandWithTimeoutMock = vi.fn(async () => ({
+  code: 0,
+  stdout: "",
+  stderr: "",
+}));
+
+vi.mock("../agents/skills.js", () => ({
+  hasBinary: () => true,
+}));
+
+vi.mock("../process/exec.js", () => ({
+  runCommandWithTimeout: runCommandWithTimeoutMock,
+}));
+
+vi.mock("./gmail-setup-utils.js", () => ({
+  ensureTailscaleEndpoint: vi.fn(async () => {}),
+}));
+
+vi.mock("./gmail.js", () => ({
+  buildGogWatchServeArgs: () => [
+    "gmail",
+    "watch",
+    "serve",
+    "--token",
+    runtimeConfig.pushToken,
+    "--hook-url",
+    runtimeConfig.hookUrl,
+    "--hook-token",
+    runtimeConfig.hookToken,
+  ],
+  buildGogWatchStartArgs: () => ["gmail", "watch", "start"],
+  resolveGmailHookRuntimeConfig: () => ({ ok: true, value: runtimeConfig }),
+}));
+
+const { startGmailWatcher, stopGmailWatcher } = await import(
+  "./gmail-watcher.js"
+);
+
+const cfg = {
+  hooks: {
+    enabled: true,
+    gmail: { account: runtimeConfig.account },
+  },
+};
+
+beforeEach(() => {
+  spawnMock.mockClear();
+  runCommandWithTimeoutMock.mockClear();
+});
+
+afterEach(async () => {
+  await stopGmailWatcher();
+  vi.useRealTimers();
+});
+
+describe("gmail watcher", () => {
+  it("does not start twice when already running", async () => {
+    const first = await startGmailWatcher(cfg);
+    const second = await startGmailWatcher(cfg);
+
+    expect(first.started).toBe(true);
+    expect(second.started).toBe(true);
+    expect(spawnMock).toHaveBeenCalledTimes(1);
+  });
+
+  it("restarts the gog watcher after a process error", async () => {
+    vi.useFakeTimers();
+
+    await startGmailWatcher(cfg);
+    const child = spawnMock.mock.results[0]?.value as MockChild | undefined;
+    expect(child).toBeDefined();
+    child?.emit("error", new Error("boom"));
+
+    expect(spawnMock).toHaveBeenCalledTimes(1);
+    await vi.advanceTimersByTimeAsync(5000);
+    expect(spawnMock).toHaveBeenCalledTimes(2);
+
+    const restartChild = spawnMock.mock.results[1]?.value as
+      | MockChild
+      | undefined;
+    const stopPromise = stopGmailWatcher();
+    restartChild?.emit("exit", 0, null);
+    await stopPromise;
+  });
+});