serf: Instructions file for Claude Code

CLAUDE.md

serf CLAUDE.md is an instructions file for Claude Code from schmidthole/serf. It costs 257 tokens per session, scanned A, original, BSD-3-Clause.

A set of Claude Code instructions describing the Serf project, its spec-driven development workflow, and its repository structure. Serf is a framework that organizes development around written feature specifications.

In plain words
What is it for?
Use it when working on Serf's skills, shared workflow documentation, plugin configuration, or user guide.
Why use it?
It gives the coding agent the project conventions it should follow when changing the plugin. It also keeps the human guide and working instructions aligned.

Instructions file for Claude Code

Written for Claude Code: the file is CLAUDE.md. Also seen: mentions .claude-plugin; mentions Claude Code.

This is schmidthole/serf's own configuration. It tells Claude Code how to work on serf itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything serf configures →

Reuse

Borrowing it

Nothing to install: this file belongs to schmidthole/serf. 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/schmidthole/serf/main/CLAUDE.md
Clone the repo
git clone --depth 1 https://github.com/schmidthole/serf

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.

agentmods badge for serf CLAUDE.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/schmidthole/serf/claude-md/github.svg)](https://agentmods.dev/instructions/schmidthole/serf/claude-md)
Your own site
<a href="https://agentmods.dev/instructions/schmidthole/serf/claude-md"><img src="https://agentmods.dev/badge/instructions/schmidthole/serf/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.

agentmods 80×15 button for serf CLAUDE.md

Your own site · 80×15
<a href="https://agentmods.dev/instructions/schmidthole/serf/claude-md"><img src="https://agentmods.dev/badge/instructions/schmidthole/serf/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 257 This file is loaded in full into every session.
When invoked 257 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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00257 $0.00257
Opus 5.5 $0.00103 $0.00103
Sonnet 5.5 $0.00051 $0.00051
Haiku 4.5 $0.00026 $0.00026

Measured 2mo ago against content hash 34a347992145, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

serf 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 · 22 lines

What it actually says

Serf

Serf is a Claude Code plugin providing a spec-driven development framework. See README.md for an overview and user-guide.md for the full workflow.

Project Structure

This repo is a Claude Code plugin. It contains no application code — only skills, conventions, and documentation.

  • .claude-plugin/ — plugin manifest and marketplace config
  • skills/ — Claude Code skills (/serf:spec-* commands)
  • skills/development-workflow.md — shared reference document used by all skills
  • user-guide.md — human-readable walkthrough of the workflow

Development

  • all skills live in skills/<skill-name>/SKILL.md
  • shared conventions live in skills/development-workflow.md and are linked from each skill via a ## reference section
  • when updating workflow conventions, edit development-workflow.md — do not duplicate the content into individual skills
  • keep skills minimal and action-oriented — they are instructions, not documentation
  • user-guide.md is the human-facing equivalent of the skills — keep it in sync when skills change
  • test plugin changes locally with claude --plugin-dir .
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. 2mo ago First seen · 22 lines · 257 tokens per session scan A 34a347992145

Subscribe to this mod's changes

serf CLAUDE.md is an instructions file published in the GitHub repository schmidthole/serf (2 stars, last pushed 7mo ago), licensed BSD-3-Clause. It adds 257 tokens to every session, about $0.0010 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 2026-08-31.

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