What is fab CLAUDE.md?

A project-specific instruction file for fab, a tool that coordinates multiple Claude Code sessions across projects. It sets coding, branding, commit, release, and file-location rules.

Use it when developing fab in Go, making commits, handling releases, or working with its configuration, daemon socket, and worktrees.

It gives coding agents consistent project context and working rules, reducing guesswork and inconsistent changes.

How tessro/fab configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to tessro/fab. 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/tessro/fab/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/tessro/fab

Made for: Claude Code.

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/tessro/fab/claude-md/github.svg)](https://agentmods.dev/instructions/tessro/fab/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/tessro/fab/claude-md"><img src="https://agentmods.dev/badge/instructions/tessro/fab/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.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/tessro/fab/claude-md"><img src="https://agentmods.dev/badge/instructions/tessro/fab/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 299 This file is loaded in full into every session.

When invoked 299 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.

Model	Per session	Once invoked
Fable 5.1	$0.00299	$0.00299
Opus 5.5	$0.00120	$0.00120
Sonnet 5.5	$0.00060	$0.00060
Haiku 4.5	$0.00030	$0.00030

Measured 2mo ago against content hash 410acac06ad3, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

fab CLAUDE.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 2mo 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.md · 42 lines

What it actually says

fab - Claude Code Instructions

Branding

Use the bus emoji 🚌 to brand the project:

README.md header
CLI output (e.g., 🚌 fab daemon started)
TUI header
Error messages where appropriate

Project Context

fab is a coding agent supervisor - it manages multiple Claude Code instances across projects with automatic task orchestration via ticket (tk).

Code Style

Go 1.25
Use standard Go project layout (cmd/, internal/)
Prefer simplicity over abstraction
Error messages should be actionable

Commits

Atomic commits: One logical change per commit
Conventional commits: type(scope): message
- Types: feat, fix, docs, chore, refactor, test
- Scope: optional, e.g., cli, tui, daemon, ticket
Keep subject line under 72 chars
Reference issue IDs in body when applicable
Push after committing - don't let commits pile up locally

Releases

Releases are CI-driven via GitHub Actions on vX.Y.Z tags
Do not use gh release manually

Key Conventions

Config lives in ~/.config/fab/config.toml
Daemon socket at ~/.fab/fab.sock
Worktrees in ~/.fab/worktrees/<project>/

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.

2mo ago First seen · 42 lines · 299 tokens per session scan A 410acac06ad3

Subscribe to this mod's changes

fab CLAUDE.md is an instructions file published in the GitHub repository tessro/fab (24 stars, last pushed 9mo ago), licensed MIT. It adds 299 tokens to every session, about $0.0012 per session on Opus 5.5. 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 2026-08-30.

fab CLAUDE.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
fab CLAUDE.mdtessro/fab	Instructions file	24	9mo ago	MIT	A	299	Claude Code
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
vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	today	MIT	A	5,649	GitHub Copilot
langchain AGENTS.mdlangchain-ai/langchain	Instructions file	149k	today	MIT	A	4,680	Codex, OpenCode
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	today	MIT	A	3,093	GitHub Copilot
vscode ai-customization.instructions.mdmicrosoft/vscode	Instructions file	195k	today	MIT	A	1,907	GitHub Copilot

fab: Instructions file for Claude Code