Borrowing it
Nothing to install: this file belongs to craigsc/cmux. 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/craigsc/cmux/main/CLAUDE.mdgit clone --depth 1 https://github.com/craigsc/cmuxWrote 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/craigsc/cmux/claude-md)<a href="https://agentmods.dev/instructions/craigsc/cmux/claude-md"><img src="https://agentmods.dev/badge/instructions/craigsc/cmux/claude-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/craigsc/cmux/claude-md"><img src="https://agentmods.dev/badge/instructions/craigsc/cmux/claude-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 | $0.00673 | $0.00673 |
| Opus 5.5 | $0.00269 | $0.00269 |
| Sonnet 5.5 | $0.00135 | $0.00135 |
| Haiku 4.5 | $0.00067 | $0.00067 |
Grade A, and why
cmux CLAUDE.md scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
- `install.sh` — curl-pipe installer that downloads cmux.sh to `~/.cmux/` and adds source line to shell RC How it starts
The opening of the file, as written. The whole thing — 50 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md
This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
What is cmux
cmux is a pure Bash shell tool that manages git worktree lifecycles for running parallel Claude Code sessions. Each worktree gets its own isolated working directory so multiple Claude agents can work on the same repo simultaneously.
Architecture
Single-file shell tool — all logic lives in cmux.sh (~560 lines), which is sourced into the user's shell (bash/zsh). There is no build step, no dependencies, and no test suite.
Function structure:
cmux()— public dispatcher, routes subcommands to_cmux_<cmd>functions_cmux_*()— private functions:_cmux_new,_cmux_start,_cmux_cd,_cmux_ls,_cmux_merge,_cmux_rm,_cmux_rm_all,_cmux_init- Helper functions:
_cmux_repo_root,_cmux_safe_name,_cmux_worktree_dir,_cmux_spinner_start/stop
Key design patterns:
- Idempotent operations (e.g.
cmux newreuses existing worktrees) - Context-aware:
cmux rmandcmux mergewith no args detect the current worktree from$PWD - Branch name sanitization:
feature/foo→feature-foofor directory names - Worktrees live under
.worktrees/<safe-branch-name>/in the repo root
Setup hook system: .cmux/setup is an executable bash script that runs after worktree creation. It handles project-specific init (symlink secrets, install deps, codegen). cmux init uses Claude CLI (claude -p) to auto-generate this hook.
Key files
cmux.sh— the entire applicationinstall.sh— curl-pipe installer that downloads cmux.sh to~/.cmux/and adds source line to shell RC.cmux/setup— project-specific worktree setup hook (committed to repo)examples/setup-node— example setup hook for Node.js projects
Shell conventions
- 2-space indentation
- Functions prefixed
_cmux_for internal,cmuxfor public - Zsh compatibility: uses
setopt localoptions nomonitorwhere needed for job control - Error handling: validate inputs, check
command -v, guard with|| return 1 - No
set -ein cmux.sh (it's sourced, not executed); install.sh usesset -e
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.
- 1mo ago First seen · 50 lines · 673 tokens per session scan A 796eb0e0f181
cmux CLAUDE.md is an instructions file published in the GitHub repository craigsc/cmux (604 stars, last pushed 4mo ago), licensed MIT. It adds 673 tokens to every session, about $0.0027 per session on Opus 5.5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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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).
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Copilot instructions for denoland/deno, covering deno development guide for github copilot, network access, high level overview, key directories and key files to understand first.