page-agent AGENTS.md

A set of AGENTS.md project instructions for Page Agent, a software project organized as a monorepo—a single repository containing several related packages. It describes the packages, project structure, and development commands.

In plain words
What is it for?
Working on Page Agent, its browser extension, website, shared libraries, user interface, controller, and language-model packages.
Why use it?
It gives coding assistants the project context and tells them how to build, test, check types, and lint the code correctly.

Instructions file for CodexOpenCode

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add instructions/alibaba/page-agent/agents-md
Clone the repo
git clone --depth 1 https://github.com/alibaba/page-agent

Made for: Codex, OpenCode.

Per session 1,603 This file is loaded in full into every session.
When invoked 1,603 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.01603 $0.01603
Opus 5 $0.00801 $0.00801
Sonnet 5 $0.00321 $0.00321
Haiku 4.5 $0.00160 $0.00160

Measured yesterday against content hash ee55826aedcf, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

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 yesterday.

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.

AGENTS.md · 152 lines

How it starts

The opening of the file, as written. The whole thing — 152 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 as page-agent on npm
  • Extension (packages/extension/) - Browser extension (WXT + React)
  • Website (packages/website/) - React docs and landing page. When working on website, follow packages/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

Read the full file on GitHub · 152 lines

Changes

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.

  1. yesterday First seen · 152 lines · 1,603 tokens per session scan A ee55826aedcf

Subscribe to this mod's changes

page-agent AGENTS.md is an instructions file published in the GitHub repository alibaba/page-agent (28,906 stars, last pushed 7d ago), licensed MIT. It adds 1,603 tokens to every session, about $0.0080 per session on Opus 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.