diff --git a/package.json b/package.json
index 7422fcd739d6..dcae99386bf6 100644
--- a/package.json
+++ b/package.json
@@ -1761,7 +1761,7 @@
     "test:restart:gateway": "node --import tsx scripts/bench-gateway-restart.ts",
     "test:startup:memory": "node scripts/ensure-cli-startup-build.mjs && node scripts/check-cli-startup-memory.mjs",
     "test:ui": "pnpm ui:i18n:check && pnpm lint:ui:no-raw-window-open && pnpm --dir ui test",
-    "test:ui:e2e": "node scripts/run-vitest.mjs run --config test/vitest/vitest.ui-e2e.config.ts --configLoader runner",
+    "test:ui:e2e": "node scripts/ensure-playwright-chromium.mjs && node scripts/run-vitest.mjs run --config test/vitest/vitest.ui-e2e.config.ts --configLoader runner",
     "test:unit": "pnpm test:unit:fast && node scripts/run-vitest.mjs run --config test/vitest/vitest.unit.config.ts",
     "test:unit:fast": "node scripts/run-vitest.mjs run --config test/vitest/vitest.unit-fast.config.ts",
     "test:unit:fast:audit": "node scripts/test-unit-fast-audit.mjs",
diff --git a/scripts/ensure-playwright-chromium.mjs b/scripts/ensure-playwright-chromium.mjs
new file mode 100644
index 000000000000..0a625f1f32af
--- /dev/null
+++ b/scripts/ensure-playwright-chromium.mjs
@@ -0,0 +1,82 @@
+#!/usr/bin/env node
+import { spawnSync as spawnSyncImpl } from "node:child_process";
+import { existsSync as existsSyncImpl, realpathSync } from "node:fs";
+import { dirname, resolve } from "node:path";
+import { fileURLToPath } from "node:url";
+import { chromium } from "playwright";
+import { resolvePnpmRunner } from "./pnpm-runner.mjs";
+
+const repoRoot = resolve(dirname(fileURLToPath(import.meta.url)), "..");
+const playwrightInstallArgs = ["--dir", "ui", "exec", "playwright", "install", "chromium"];
+
+export function resolvePlaywrightInstallRunner(options = {}) {
+  const env = options.env ?? process.env;
+  return resolvePnpmRunner({
+    comSpec: options.comSpec ?? env.ComSpec ?? env.COMSPEC,
+    npmExecPath: env.npm_execpath,
+    platform: options.platform,
+    pnpmArgs: playwrightInstallArgs,
+  });
+}
+
+export function isDirectScriptExecution(
+  argvEntry = process.argv[1],
+  modulePath = fileURLToPath(import.meta.url),
+  realpath = realpathSync.native,
+) {
+  if (!argvEntry) {
+    return false;
+  }
+  try {
+    return realpath(argvEntry) === realpath(modulePath);
+  } catch {
+    return resolve(argvEntry) === resolve(modulePath);
+  }
+}
+
+export function ensurePlaywrightChromium(options = {}) {
+  const env = options.env ?? process.env;
+  const executablePath = options.executablePath ?? chromium.executablePath();
+  const existsSync = options.existsSync ?? existsSyncImpl;
+  const log = options.log ?? console.error;
+  const spawnSync = options.spawnSync ?? spawnSyncImpl;
+
+  if (existsSync(executablePath)) {
+    return 0;
+  }
+
+  if (env.OPENCLAW_UI_E2E_ALLOW_MISSING_CHROMIUM === "1") {
+    log(
+      `[ui-e2e] Playwright Chromium is missing at ${executablePath}; OPENCLAW_UI_E2E_ALLOW_MISSING_CHROMIUM=1 leaves the lane skipped.`,
+    );
+    return 0;
+  }
+
+  log(`[ui-e2e] Playwright Chromium is missing at ${executablePath}; installing chromium.`);
+  const runner = resolvePlaywrightInstallRunner({
+    comSpec: options.comSpec,
+    env,
+    platform: options.platform,
+  });
+  const result = spawnSync(runner.command, runner.args, {
+    cwd: options.cwd ?? repoRoot,
+    env,
+    shell: runner.shell,
+    stdio: options.stdio ?? "inherit",
+    windowsVerbatimArguments: runner.windowsVerbatimArguments,
+  });
+  const status = result.status ?? 1;
+  if (status !== 0) {
+    return status;
+  }
+
+  if (!existsSync(executablePath)) {
+    log(`[ui-e2e] Playwright install completed but Chromium is still missing at ${executablePath}.`);
+    return 1;
+  }
+  return 0;
+}
+
+if (isDirectScriptExecution()) {
+  process.exitCode = ensurePlaywrightChromium();
+}
diff --git a/test/scripts/ensure-playwright-chromium.test.ts b/test/scripts/ensure-playwright-chromium.test.ts
new file mode 100644
index 000000000000..654f89988c4c
--- /dev/null
+++ b/test/scripts/ensure-playwright-chromium.test.ts
@@ -0,0 +1,96 @@
+import { describe, expect, it, vi } from "vitest";
+import {
+  ensurePlaywrightChromium,
+  resolvePlaywrightInstallRunner,
+} from "../../scripts/ensure-playwright-chromium.mjs";
+
+describe("ensurePlaywrightChromium", () => {
+  it("does nothing when the browser binary exists", () => {
+    const spawnSync = vi.fn();
+
+    expect(
+      ensurePlaywrightChromium({
+        executablePath: "/cache/chromium/chrome",
+        existsSync: () => true,
+        spawnSync,
+      }),
+    ).toBe(0);
+    expect(spawnSync).not.toHaveBeenCalled();
+  });
+
+  it("preserves the intentional missing-browser skip mode", () => {
+    const logs: string[] = [];
+    const spawnSync = vi.fn();
+
+    expect(
+      ensurePlaywrightChromium({
+        env: { OPENCLAW_UI_E2E_ALLOW_MISSING_CHROMIUM: "1" },
+        executablePath: "/cache/chromium/chrome",
+        existsSync: () => false,
+        log: (line: string) => logs.push(line),
+        spawnSync,
+      }),
+    ).toBe(0);
+    expect(spawnSync).not.toHaveBeenCalled();
+    expect(logs.join("\n")).toContain("leaves the lane skipped");
+  });
+
+  it("installs Chromium through the UI Playwright package when missing", () => {
+    const spawnSync = vi.fn(() => ({ status: 0 }));
+    let existsCalls = 0;
+
+    expect(
+      ensurePlaywrightChromium({
+        cwd: "/repo",
+        env: { PATH: "/bin" },
+        executablePath: "/cache/chromium/chrome",
+        existsSync: () => ++existsCalls > 1,
+        platform: "linux",
+        spawnSync,
+        stdio: "pipe",
+      }),
+    ).toBe(0);
+    expect(spawnSync).toHaveBeenCalledWith(
+      "pnpm",
+      ["--dir", "ui", "exec", "playwright", "install", "chromium"],
+      {
+        cwd: "/repo",
+        env: { PATH: "/bin" },
+        shell: false,
+        stdio: "pipe",
+        windowsVerbatimArguments: undefined,
+      },
+    );
+  });
+
+  it("returns the installer status when Playwright install fails", () => {
+    expect(
+      ensurePlaywrightChromium({
+        executablePath: "/cache/chromium/chrome",
+        existsSync: () => false,
+        spawnSync: vi.fn(() => ({ status: 23 })),
+        stdio: "pipe",
+      }),
+    ).toBe(23);
+  });
+
+  it("wraps the pnpm command shim on Windows", () => {
+    expect(
+      resolvePlaywrightInstallRunner({
+        comSpec: "C:\\Windows\\System32\\cmd.exe",
+        env: {},
+        platform: "win32",
+      }),
+    ).toEqual({
+      args: [
+        "/d",
+        "/s",
+        "/c",
+        'pnpm.cmd --dir ui exec playwright install chromium',
+      ],
+      command: "C:\\Windows\\System32\\cmd.exe",
+      shell: false,
+      windowsVerbatimArguments: true,
+    });
+  });
+});
diff --git a/ui/src/test-helpers/control-ui-e2e.ts b/ui/src/test-helpers/control-ui-e2e.ts
index 22bb13d841d1..548a5b4b87dc 100644
--- a/ui/src/test-helpers/control-ui-e2e.ts
+++ b/ui/src/test-helpers/control-ui-e2e.ts
@@ -1,4 +1,5 @@
 import { existsSync } from "node:fs";
+import { createRequire } from "node:module";
 import { createServer as createNetServer } from "node:net";
 import path from "node:path";
 import { fileURLToPath } from "node:url";
@@ -7,6 +8,9 @@ import { createServer, type ViteDevServer } from "vite";
 import { CONTROL_UI_BOOTSTRAP_CONFIG_PATH } from "../../../src/gateway/control-ui-contract.js";
 import { PROTOCOL_VERSION } from "../../../src/gateway/protocol/version.js";
 
+const require = createRequire(import.meta.url);
+const json5EsmPath = require.resolve("json5/dist/index.mjs");
+
 export type MockGatewayRequest = {
   id: string;
   method: string;
@@ -69,9 +73,14 @@ export async function startControlUiE2eServer(): Promise<ControlUiE2eServer> {
     },
     logLevel: "error",
     optimizeDeps: {
-      include: ["lit/directives/repeat.js"],
+      include: ["ipaddr.js", "lit/directives/repeat.js", "markdown-it-task-lists"],
     },
     publicDir: path.join(uiRoot, "public"),
+    resolve: {
+      alias: {
+        json5: json5EsmPath,
+      },
+    },
     root: uiRoot,
     server: {
       host: "127.0.0.1",
diff --git a/ui/vite.config.ts b/ui/vite.config.ts
index 6ec209f76a37..0c6d4d316851 100644
--- a/ui/vite.config.ts
+++ b/ui/vite.config.ts
@@ -1,5 +1,6 @@
 import { execFileSync } from "node:child_process";
 import fs from "node:fs";
+import { createRequire } from "node:module";
 import path from "node:path";
 import { fileURLToPath } from "node:url";
 import { defineConfig, type Plugin } from "vite";
@@ -8,6 +9,8 @@ import { controlUiManualChunk } from "./config/control-ui-chunking.ts";
 const here = path.dirname(fileURLToPath(import.meta.url));
 const repoRoot = path.resolve(here, "..");
 const outDir = path.resolve(here, "../dist/control-ui");
+const require = createRequire(import.meta.url);
+const json5EsmPath = require.resolve("json5/dist/index.mjs");
 
 function normalizeBase(input: string): string {
   const trimmed = input.trim();
@@ -93,7 +96,12 @@ export default defineConfig(() => {
     },
     publicDir: path.resolve(here, "public"),
     optimizeDeps: {
-      include: ["lit/directives/repeat.js"],
+      include: ["ipaddr.js", "lit/directives/repeat.js", "markdown-it-task-lists"],
+    },
+    resolve: {
+      alias: {
+        json5: json5EsmPath,
+      },
     },
     build: {
       outDir,