Borrowing it
Nothing to install: this file belongs to briandconnelly/codex-in-claude. 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/briandconnelly/codex-in-claude/main/AGENTS.mdgit clone --depth 1 https://github.com/briandconnelly/codex-in-claudeWrote 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/briandconnelly/codex-in-claude/agents-md)<a href="https://agentmods.dev/instructions/briandconnelly/codex-in-claude/agents-md"><img src="https://agentmods.dev/badge/instructions/briandconnelly/codex-in-claude/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/briandconnelly/codex-in-claude/agents-md"><img src="https://agentmods.dev/badge/instructions/briandconnelly/codex-in-claude/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 | $0.06484 | $0.06484 |
| Opus 5 | $0.03242 | $0.03242 |
| Sonnet 5 | $0.01297 | $0.01297 |
| Haiku 4.5 | $0.00648 | $0.00648 |
Grade A, and why
codex-in-claude 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 8d 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 — 370 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Agent working conventions
Conventions for any agent (or human) working in this repository.
What this is
A Claude Code plugin that calls the OpenAI Codex CLI via a FastMCP server. The Python package
is codex_in_claude under src/. Generic, CLI-agnostic machinery lives in the shared
pontonier library (pontonier.core and the frozen
pontonier.backend protocol), which this package consumes as a dependency — the planned
extraction of the old in-repo _core/ happened.
- Rule: this bridge pins its externally visible core knobs explicitly
(
config.WORKTREE_CONFIG: worktree prefix, baseline-commit identity) rather than inheriting pontonier defaults; changing them is a behavior change, not a refactor. - The declarative half of the CLI contract also lives as
cli_contract.PONTONIER_CONTRACT(the sharedBackendContractshape) with tests pinning its derivation from the legacy constants, andbackend.CodexBackendadapts this bridge onto the frozen pontonierAgentBackendprotocol (contract_api_version = 1), which every model-bearing run is staged through.
Package boundary
Which repo a change belongs in — this bridge or upstream pontonier. This section is the single
home for that decision; other docs link here rather than restating it. pontonier's own README
lists what the shared library already exposes — read it there rather than keeping a copy of that
list in this repo.
Two questions route an ordinary change:
- Does the code have to know it is talking to
codex? If yes, it stays here. - Does it extend an abstraction
pontonieralready exposes, or does another bridge have the same confirmed need? If yes, it goes upstream.
Question 1 wins when both answer yes: Codex-aware code never moves upstream, and a change that needs both halves is the mixed change below. If neither question gives a yes, keep the code here. Absence of the word "codex" is not evidence that a mechanism is shared, and a second caller that does not exist yet is not a requirement.
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.
- 8d ago First seen · 370 lines · 6,484 tokens per session scan A b8af2bb85cfd
codex-in-claude AGENTS.md is an instructions file published in the GitHub repository briandconnelly/codex-in-claude (3 stars, last pushed 5d ago), licensed MIT. It adds 6,484 tokens to every session, about $0.0324 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.
Other instructions, from other repositories
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.
codex AGENTS.md
AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.
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).
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, applying the notice (cutover) and fallback chain (never fail the build).
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.
spec-kit AGENTS.md
AGENTS.md instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.