What is codex-mcp-bridge AGENTS.md?

Repository-specific instructions for codex-mcp-bridge, an open-source server that lets coding tools use the Codex command-line program through the Model Context Protocol.

Guiding work on the TypeScript server, its subprocess architecture, prompt templates, code review paths, and exposed code-execution or search tools.

It explains the project’s structure, available tools, and which tool fits each task, reducing incorrect changes in an unfamiliar codebase.

How hampsterx/codex-mcp-bridge configures Codex and OpenCode

Reuse

Borrowing it

Nothing to install: this file belongs to hampsterx/codex-mcp-bridge. 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/hampsterx/codex-mcp-bridge/master/AGENTS.md

Clone the repo

git clone --depth 1 https://github.com/hampsterx/codex-mcp-bridge

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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/hampsterx/codex-mcp-bridge/agents-md/github.svg)](https://agentmods.dev/instructions/hampsterx/codex-mcp-bridge/agents-md)

Your own site

<a href="https://agentmods.dev/instructions/hampsterx/codex-mcp-bridge/agents-md"><img src="https://agentmods.dev/badge/instructions/hampsterx/codex-mcp-bridge/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.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/hampsterx/codex-mcp-bridge/agents-md"><img src="https://agentmods.dev/badge/instructions/hampsterx/codex-mcp-bridge/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 3,746 This file is loaded in full into every session.

When invoked 3,746 The same file — it is already loaded in full.

Security scan B 1 finding. 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.

Model	Per session	Once invoked
Fable 5.1	$0.03746	$0.03746
Opus 5.5	$0.01498	$0.01498
Sonnet 5.5	$0.00749	$0.00749
Haiku 4.5	$0.00375	$0.00375

Measured 17d ago against content hash 0acde7749d9e, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade B, and why

codex-mcp-bridge AGENTS.md scanned grade B with 1 finding 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 17d 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.

Reads agent configuration directoriesmediumAgent snooping

.claude/, .codex/, .gemini/ hold keys, settings and other credentials a mod has no legitimate need for.

Controls which MCP servers from `~/.codex/config.toml`, and from any project

AGENTS.md · 242 lines

How it starts

The opening of the file, as written. The whole thing — 242 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md - codex-mcp-bridge

Guidance for AI coding agents working in the codex-mcp-bridge repository.

This file defines repository-specific operating rules for autonomous or semi-autonomous coding agents. Follow these instructions unless a maintainer explicitly tells you otherwise.

Project Overview

Open source MCP server that wraps Codex CLI as a subprocess, exposing code execution, web search, and structured output as MCP tools. Works with any MCP-compatible client: Claude Code, Gemini CLI, Cursor, Windsurf, VS Code.

npm package: codex-mcp-bridge
License: MIT
Language: TypeScript
Framework: @modelcontextprotocol/sdk

Architecture

MCP Client  --stdio-->  codex-mcp-bridge  --spawn-->  codex CLI subprocess

Prompts are assembled in TypeScript and spawned via the CLI. The search and query tools load prompt templates from prompts/*.md via src/utils/prompts.ts and fill placeholders. The codex tool is fully caller-driven: callers pass any prompt and pick the sandbox level. Code review has two paths per ADR-001: the review tool wraps upstream's diff-aware codex exec review --json and carries no prompt of its own, while free-form review is caller-authored through the codex tool with sandbox: "read-only" (see README § Code review with this CLI).

Tools

Tool	Purpose	Default Timeout
`codex`	Execute prompts with file context, session resume, sandbox control	60s
`review`	Native diff-aware review, prompt-free (see below)	180s
`search`	Web search via `codex --search`	120s
`query`	Lightweight text analysis (no repo context, no sessions)	60s
`structured`	JSON Schema validated output (Ajv)	60s
`ping`	Health check + CLI capability detection	10s
`mcpStatus`	Per-server MCP boot state via `codex app-server`	90s/request
`listSessions`	List active Codex conversation sessions	30s

Read the full file on GitHub · 242 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.

17d ago Changed · +20 lines · +303 tokens per session 0acde7749d9e
2mo ago First seen · 222 lines · 3,443 tokens per session scan B dc9b942ec0e6

Subscribe to this mod's changes

codex-mcp-bridge AGENTS.md is an instructions file published in the GitHub repository hampsterx/codex-mcp-bridge (3 stars, last pushed 18d ago), licensed MIT. It adds 3,746 tokens to every session, about $0.0150 per session on Opus 5.5. A static security scan graded it B with 1 finding (reads agent configuration directories). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Building agents

codex-mcp-bridge AGENTS.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
codex-mcp-bridge AGENTS.mdhampsterx/codex-mcp-bridge	Instructions file	3	18d ago	MIT	B	3,746	Codex, OpenCode
vscode buildNext.instructions.mdmicrosoft/vscode	Instructions file	195k	today	MIT	A	9,719	GitHub Copilot
next.js AGENTS.mdvercel/next.js	Instructions file	143k	today	MIT	A	7,461	Codex, OpenCode
langchain AGENTS.mdlangchain-ai/langchain	Instructions file	149k	today	MIT	A	4,680	Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	today	MIT	A	5,516	GitHub Copilot
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	today	MIT	A	3,093	GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness	Instructions file	275k	2d ago	MIT	A	4,313	Codex, OpenCode

codex-mcp-bridge: Instructions file for Codex