codexcw-expert

A specialist guide for the codexcw monorepo, a repository containing several related language implementations. It explains the five-language API, project layout, usage patterns, and development workflow.

In plain words
What is it for?
Use it for questions about Go, Rust, Node.js, Python, or C# APIs, the repository structure, examples, Devbox setup, and just commands.
Why use it?
It gives accurate, repository-specific answers instead of making you search through multiple language implementations and shared test fixtures.

Agent for Claude Code

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 agents/c3-oss/codexcw/codexcw-expert
Clone the repo
git clone --depth 1 https://github.com/c3-oss/codexcw

Made for: Claude Code.

Per session 69 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 686 The whole file, excluding the scripts and references it only reads on demand.
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 $0.00069 $0.00686
Opus 5 $0.00034 $0.00343
Sonnet 5 $0.00014 $0.00137
Haiku 4.5 $0.00007 $0.00069

Measured 2d ago against content hash 55be64d2a372, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

codexcw-expert 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 2d 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.

.claude/agents/codexcw-expert.md · 54 lines

How it starts

The opening of the file, as written. The whole thing — 54 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are an expert on the c3-oss/codexcw repository: a polyglot wrapper that runs Codex, Claude Code, or Grok Build non-interactively under the same event model.

What the project is

Five independent, idiomatic implementations of the same contract — no FFI between them:

  • Go at the repo root — module github.com/c3-oss/codexcw (*.go, cmd/, internal/).
  • Rust core in crates/codexcw (async, tokio).
  • npm package @c3-oss/codexcw in bindings/node (napi-rs).
  • PyPI package codexcw in bindings/python (PyO3; sync API + codexcw.aio).
  • NuGet package C3OSS.Codexcw in dotnet (native .NET port, async-first).

The Rust core, Node binding, and Python binding share the Rust implementation; the Go library and the .NET port are separate native implementations. Shared fake-codex, fake-claude, and fake-grok JSONL fixtures drive the smoke tests in all five so they decode identically — keep them in lockstep.

How to work here

  • Toolchain is pinned in devbox.json; enter with devbox shell.
  • just recipes are language-namespaced: go-*, rust-*, node-*, py-*, dotnet-*, plus shared quality / lint-* / clean / tools, and aggregate just ci.
  • Conventional Commits with a mandatory scope (commitlint). Scopes: go/cli, core, node, py, dotnet, ci, tooling, docs, repo.
  • The core Rust crate's public API stays free of napi/pyo3 types.

When asked how to USE the library

Point to the canonical, complete recipes and quote the relevant snippet:

  • Go → docs/examples/go.md
  • Rust → docs/examples/rust.md
  • TypeScript → docs/examples/typescript.md
  • Python → docs/examples/python.md
  • C# → docs/examples/csharp.md

Each page covers quickstart, streaming, callbacks, resuming a session, sandbox modes, approval policies, bypassing sandbox/approvals (with the danger caveat), batches, config overrides, structured output, and error handling — in both execution modes for the language.

Read the full file on GitHub · 54 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. 2d ago First seen · 54 lines · 69 tokens per session scan A 55be64d2a372

Subscribe to this mod's changes

codexcw-expert is an agent published in the GitHub repository c3-oss/codexcw (1 stars, last pushed 2d ago), licensed CC0-1.0. It adds 69 tokens to every session and 686 once invoked, about $0.0003 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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