Page Agent

page-agent

alibaba/page-agent (https://github.com/alibaba/page-agent, 17k+ stars, MIT) is an in-page GUI agent written in TypeScript. It lives inside a webpage, reads the DOM as text (no screenshots, no multi-modal LLM), and executes natural-language instructions like "click the login button, then fill username as John" against the current page. Pure client-side — the host site includes a script and passes an OpenAI-compatible LLM endpoint.

When to Use

Load this skill when a user wants to:

1. Ship an AI copilot inside their own web app (SaaS, admin panel, B2B tool, ERP, CRM) — e.g., "users on my dashboard should be able to type 'create invoice for Acme Corp and email it' instead of clicking through five screens."
2. Modernize a legacy web app without rewriting the frontend — page-agent drops on top of existing DOM.
3. Add accessibility via natural language — voice / screen-reader users drive the UI by describing what they want.
4. Demo or evaluate page-agent against a local (Ollama) or hosted (Qwen, OpenAI, OpenRouter) LLM.
5. Build interactive training / product demos — let an AI walk a user through "how to submit an expense report" live in the real UI.

When NOT to use

• User wants the agent itself to drive a browser → use a built-in browser tool (Browserbase / Camofox). page-agent is the opposite direction: it runs inside the page.
• User wants cross-tab automation without embedding → use Playwright, browser-use, or the page-agent Chrome extension.
• User needs visual grounding / screenshots → page-agent is text-DOM only; use a multimodal browser agent instead.

Prerequisites

• Node 22.13+ or 24+, npm 10+ (docs claim 11+ but npm 10.9 works fine).
• An OpenAI-compatible LLM endpoint: Qwen (DashScope), OpenAI, Ollama, OpenRouter, or anything speaking /v1/chat/completions.
• Browser with devtools (for debugging).
• On Windows, use PowerShell for all npm / git commands below. Paths like ~\project are standard; no WSL required.

Procedure

Path 1 — 30-second demo via CDN (no install)

Fastest way to see it work. Uses alibaba's free testing LLM proxy — for evaluation only, subject to their terms.

1. Add the following <script> tag to any HTML page (or paste the bookmarklet into the devtools console):

<script src="https://cdn.jsdelivr.net/npm/page-agent@1.8.0/dist/iife/page-agent.demo.js" crossorigin="true"></script>

2. A floating panel appears. Type an instruction (e.g., "click the Login link"). Done.

Bookmarklet form (drop into bookmarks bar, click on any page):

javascript:(function(){var s=document.createElement('script');s.src='https://cdn.jsdelivr.net/npm/page-agent@1.8.0/dist/iife/page-agent.demo.js';document.head.appendChild(s);})();

Path 2 — npm install into your own web app (production use)

1. Inside an existing web project (React / Vue / Svelte / plain), install the package:

npm install page-agent

2. Wire it up with your own LLM endpoint — never ship the demo CDN to real users:

import { PageAgent } from 'page-agent'

const agent = new PageAgent({
    model: 'qwen3.5-plus',
    baseURL: 'https://dashscope.aliyuncs.com/compatible-mode/v1',
    apiKey: process.env.LLM_API_KEY,   // never hardcode
    language: 'en-US',
})

// Show the panel for end users:
agent.panel.show()

// Or drive it programmatically:
await agent.execute('Click submit button, then fill username as John')

3. Choose your provider (any OpenAI-compatible endpoint works):

4. Key config fields (passed to new PageAgent({...})):

   • model, baseURL, apiKey — LLM connection
   • language — UI language (en-US, zh-CN, etc.)
   • Allowlist and data-masking hooks exist for locking down what the agent can touch — see https://alibaba.github.io/page-agent/ for the full option list

5. Security hardening for production: Don't put your apiKey in client-side code for a real deployment — proxy LLM calls through your backend and point baseURL at your proxy. The demo CDN exists because alibaba runs that proxy for evaluation.

Path 3 — clone the source repo (contributing or hacking on it)

Use this when the user wants to modify page-agent itself, test it against arbitrary sites via a local IIFE bundle, or develop the browser extension.

1. Clone and install:

git clone https://github.com/alibaba/page-agent.git
cd page-agent
npm ci              # exact lockfile install (or `npm i` to allow updates)

2. Create .env in the repo root with an LLM endpoint. Example (cloud):

LLM_MODEL_NAME=gpt-4o-mini
LLM_API_KEY=sk-...
LLM_BASE_URL=https://api.openai.com/v1

Ollama flavor:

LLM_BASE_URL=http://localhost:11434/v1
LLM_API_KEY=NA
LLM_MODEL_NAME=qwen3:14b

3. Common commands:

npm start           # docs/website dev server
npm run build       # build every package
npm run dev:demo    # serve IIFE bundle at http://localhost:5174/page-agent.demo.js
npm run dev:ext     # develop the browser extension (WXT + React)
npm run build:ext   # build the extension

4. Test on any website using the local IIFE bundle. Add this bookmarklet:

javascript:(function(){var s=document.createElement('script');s.src=`http://localhost:5174/page-agent.demo.js?t=${Math.random()}`;s.onload=()=>console.log('PageAgent ready!');document.head.appendChild(s);})();

5. Run npm run dev:demo, click the bookmarklet on any page, and the local build injects. Auto-rebuilds on save.

HARD RULE — dev bundle key exposure: Your .env LLM_API_KEY is inlined into the IIFE bundle during dev builds. Don't share the bundle. Don't commit it. Don't paste the URL into Slack. (Verified: grepping the public dev bundle returns the literal values from .env.)

Repo layout (Path 3)

Monorepo with npm workspaces. Key packages:

Pitfalls

1. Demo CDN in production — don't. It's rate-limited, uses alibaba's free proxy, and their terms forbid production use.
2. API key exposure — any key passed to new PageAgent({apiKey: ...}) ships in your JS bundle. Always proxy through your own backend for real deployments.
3. Non-OpenAI-compatible endpoints fail silently or with cryptic errors. If your provider needs native Anthropic/Gemini formatting, use an OpenAI-compatibility proxy (LiteLLM, OpenRouter) in front.
4. CSP blocks — sites with strict Content-Security-Policy may refuse to load the CDN script or disallow inline eval. In that case, self-host from your origin.
5. Restart dev server after editing .env in Path 3 — Vite only reads env at startup.
6. Node version — the repo declares ^22.13.0 || >=24. Node 20 will fail npm ci with engine errors.
7. npm 10 vs 11 — docs say npm 11+; npm 10.9 actually works fine.
8. Dev bundle leaks .env values — see HARD RULE above. Never distribute the dev IIFE bundle publicly.

Verification

After Path 1 or Path 2

1. Open the page in a browser with devtools open.
2. You should see a floating panel. If not, check the console for errors (most common: CORS on the LLM endpoint, wrong baseURL, or a bad API key).
3. Type a simple instruction matching something visible on the page (e.g., "click the Login link").
4. Watch the Network tab — you should see a request to your baseURL.

After Path 3

1. npm run dev:demo prints Accepting connections at http://localhost:5174.
2. Verify the bundle is served:

curl -I http://localhost:5174/page-agent.demo.js

Expected output: HTTP/1.1 200 OK with Content-Type: application/javascript.

3. Click the bookmarklet on any site; panel appears.

Reference

• Repo: https://github.com/alibaba/page-agent
• Docs: https://alibaba.github.io/page-agent/
• License: MIT (built on browser-use's DOM processing internals, Copyright 2024 Gregor Zunic)