Page Agent is a JavaScript library that embeds a natural-language agent inside a web page and lets it operate the page through its text-based DOM. It is used for web copilots, form filling, accessibility, and browser workflows, while the catalogue entries provide agent skills and instructions for using it.
Borrowing it
Nothing to install: this file belongs to alibaba/page-agent. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/alibaba/page-agent/main/AGENTS.mdgit clone --depth 1 https://github.com/alibaba/page-agentWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/alibaba/page-agent/agents-md)<a href="https://agentmods.dev/instructions/alibaba/page-agent/agents-md"><img src="https://agentmods.dev/badge/instructions/alibaba/page-agent/agents-md/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/alibaba/page-agent/agents-md"><img src="https://agentmods.dev/badge/instructions/alibaba/page-agent/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.01630 | $0.01630 |
| Opus 5.5 | $0.00652 | $0.00652 |
| Sonnet 5.5 | $0.00326 | $0.00326 |
| Haiku 4.5 | $0.00163 | $0.00163 |
Grade A, and why
page-agent AGENTS.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 153 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Instructions for Coding Assistants
Project Overview
This is a monorepo with npm workspaces:
- Page Agent (
packages/page-agent/) - Main entry with built-in UI Panel, published aspage-agenton npm - Extension (
packages/extension/) - Browser extension (WXT + React) - Website (
packages/website/) - React docs and landing page. When working on website, followpackages/website/AGENTS.md
Internal packages:
- Core (
packages/core/) - PageAgentCore without UI (npm:@page-agent/core) - LLMs (
packages/llms/) - LLM client with reflection-before-action mental model - Page Controller (
packages/page-controller/) - DOM operations and visual feedback (SimulatorMask), independent of LLM - UI (
packages/ui/) - Panel and i18n. Decoupled from PageAgent
Development Commands
npm start # Start website dev server
npm run build # Build all packages
npm run build:libs # Build all libraries
npm run build:ext # Build and zip the extension package
npm run typecheck # Typecheck all packages
npm run test # Run unit tests across all workspaces
npm run lint # ESLint
Architecture
Monorepo Structure
Source-first monorepo: library package.json exports point to src/*.ts during development. At publish time, scripts/pre-publish.js promotes publishConfig fields to top-level (swapping to dist/), and scripts/post-publish.js restores the originals.
packages/
├── core/ # npm: "@page-agent/core" ⭐ Core agent logic (headless)
├── page-agent/ # npm: "page-agent" entry class (with UI + controller + demo builds)
├── website/ # @page-agent/website (private)
├── llms/ # @page-agent/llms
├── extension/ # Browser extension
├── page-controller/ # @page-agent/page-controller
└── ui/ # @page-agent/ui
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago Changed · +1 lines · +27 tokens per session dfe206c5c353
- 2mo ago First seen · 152 lines · 1,603 tokens per session scan A ee55826aedcf
page-agent AGENTS.md is an instructions file published in the GitHub repository alibaba/page-agent (29,595 stars, last pushed 8d ago), licensed MIT. It adds 1,630 tokens to every session, about $0.0065 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).
deepseek-harness AGENTS.md
AGENTS.md instructions for deepseek-ai/deepseek-harness, covering agents.md, pre-stable apis and released session data, repository layout, commands and host sandbox failures.