Agent-Worlds: Instructions file for Codex

AGENTS.md

Agent-Worlds AGENTS.md is an instructions file for Codex, OpenCode from hjl2004-10/Agent-Worlds. It costs 624 tokens per session, scanned A, original, MIT.

Repository instructions for Agent-Worlds, covering response language, file access, project locations, and browser-tool usage. MCP means a standard way for an agent to connect to external tools.

In plain words
What is it for?
They help agents work with the Python backend, frontend workspace, local development servers, and browser testing or debugging through Playwright and Chrome tools.
Why use it?
They give agents consistent rules for exploring the repository, editing safely, running the application, and choosing between its browser tools.

Instructions file for CodexOpenCode

Written for Codex and OpenCode: the file is AGENTS.md. Also seen: mentions AGENTS.md.

This is hjl2004-10/Agent-Worlds's own configuration. It tells Codex and OpenCode how to work on Agent-Worlds itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything Agent-Worlds configures →

Reuse

Borrowing it

Nothing to install: this file belongs to hjl2004-10/Agent-Worlds. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/hjl2004-10/Agent-Worlds/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/hjl2004-10/Agent-Worlds

Made for: Codex, OpenCode.

Wrote 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.

agentmods badge for Agent-Worlds AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/hjl2004-10/agent-worlds/agents-md.svg)](https://agentmods.dev/instructions/hjl2004-10/agent-worlds/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/hjl2004-10/agent-worlds/agents-md"><img src="https://agentmods.dev/badge/instructions/hjl2004-10/agent-worlds/agents-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 624 This file is loaded in full into every session.
When invoked 624 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00624 $0.00624
Opus 5 $0.00312 $0.00312
Sonnet 5 $0.00125 $0.00125
Haiku 4.5 $0.00062 $0.00062

Measured 7d ago against content hash 33b1e7ff6ece, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

Agent-Worlds 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 7d 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.

AGENTS.md · 98 lines

How it starts

The opening of the file, as written. The whole thing — 98 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md

Scope

These instructions apply to the entire repository rooted at this directory.

General

  • Prefer concise Chinese when replying to the user, unless the user asks for another language.
  • Read only the files needed for the current task. Do not bulk-read the whole repo.
  • Before editing code, inspect the relevant files first.
  • Prefer rg / rg --files for search.
  • Use non-destructive commands by default.

Project Notes

  • Backend entry: main.py
  • Frontend workspace: static/
  • Frontend dev URL is usually http://localhost:5173/
  • Backend API is usually on port 5000

MCP Usage

This workspace is configured with two browser MCPs:

  1. mcp__playwright__*
  2. mcp__chrome-devtools__*

Use them with clear division of responsibility instead of mixing them randomly.

Playwright MCP

Prefer Playwright MCP for user-like interaction and functional UI testing.

  • Use it for:
    • opening pages
    • clicking buttons, tabs, links
    • typing into forms
    • running short end-to-end UI flows
    • taking interaction-oriented snapshots/screenshots
  • Prefer it when the goal is:
    • "test whether the page works"
    • "reproduce the user path"
    • "verify a control can be clicked"

Guidelines:

  • Use role/text/ref-based actions when possible.
  • Keep flows short and deterministic.
  • Avoid repeatedly requesting full-page snapshots if a single action result is enough.
  • If token cost matters, do not overuse browser_snapshot after every step.

Chrome DevTools MCP

Prefer Chrome DevTools MCP for browser-side debugging and inspection.

  • Use it for:
    • console inspection
    • network request inspection
    • page structure snapshots
    • performance or low-level browser debugging
    • request-level investigation
  • Prefer it when the goal is:
    • "find frontend errors"
    • "inspect polling / xhr / fetch traffic"
    • "check what the browser is actually loading"
    • "analyze console warnings"

Guidelines:

  • Prefer DevTools MCP over Playwright MCP for network-heavy analysis.
  • Use filtered request listing where possible instead of dumping everything.
  • Use console listing before guessing about frontend failures.

Read the full file on GitHub · 98 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. 7d ago First seen · 98 lines · 624 tokens per session scan A 33b1e7ff6ece

Subscribe to this mod's changes

Agent-Worlds AGENTS.md is an instructions file published in the GitHub repository hjl2004-10/Agent-Worlds (7 stars, last pushed 6d ago), licensed MIT. It adds 624 tokens to every session, about $0.0031 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 2026-08-31.

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