commit-message

A writing guide for Git commit messages, the short records attached to saved changes in a code repository. It covers the subject line, explanation, optional metadata, formatting, and project-specific wording.

In plain words
What is it for?
Use it when creating, editing, or rewriting a commit message, including messages for Linux kernel patches or stacked patches.
Why use it?
It helps developers write change records that are consistent and explain why a change was needed, making project history easier to review and understand.

Skill for Claude CodeCodex

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 skills/chucklever/cel-kdev/commit-message
Any agent
npx skills add chucklever/cel-kdev --skill commit-message
Clone the repo
git clone --depth 1 https://github.com/chucklever/cel-kdev

Made for: Claude Code, Codex.

Per session 146 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,946 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 $0.00146 $0.02946
Opus 5 $0.00073 $0.01473
Sonnet 5 $0.00029 $0.00589
Haiku 4.5 $0.00015 $0.00295

Measured yesterday against content hash 6ff72a38c4b4, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

commit-message 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 yesterday.

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.

plugin/cel-prose/skills/commit-message/SKILL.md · 274 lines

How it starts

The opening of the file, as written. The whole thing — 274 lines — stays where its author put it; the contents beside it link to each section on GitHub.

commit-message

How to write a commit message in Chuck's voice, in any repository. This skill governs the message text. The mechanics of committing (git, stg) and sending (b4/series-send) live in the cel-kdev:stg and series-send skills; load those for the workflow, this for the prose.

Linux kernel patches take one more file. Read references/kernel.md before drafting one. Everything below still applies; the reference covers where the kernel departs from it -- subject case, the trailer block, sign-off ownership -- and carries the kernel worked examples.

The shape of a commit message

component: imperative summary, no trailing period

Body that opens with why the change is necessary -- the problem,
the user-visible symptom, the invariant being restored -- before
it says what changed. Flowing prose, wrapped at 72 columns.

Trailers, when the project uses them.

Subject line

The subject is a one-line claim a reader scans in git log --oneline, so it must read as a specific action, not a topic.

  • Prefix with the component, then : , then an imperative summary (fix, add, remove -- not fixed, adds, fixing).
  • Find the prevailing prefix by reading git log --oneline for the files you touched; match what that project already uses (stg:, mcp:, reviewer:, scripts:). Do not invent a new prefix where one is established, and do not impose one on a project whose log carries none -- the Internet-Draft repositories take a bare imperative summary.
  • Capitalization after the prefix follows the project, so read it off the same git log --oneline: your own repositories capitalize the summary (stg: Scope the orientation call on a deep stack), while the Linux kernel lowercases it.
  • No trailing period. Keep it under ~70 columns; the summary should survive on its own.

Body: why before what

Lead with why the change is necessary, not what changed. The diff already shows what changed; what it cannot show is the problem that made the change necessary -- the race, the leak, the spec requirement, the symptom a user hit. Open there. Only once the motivation is established does the body say what the commit does about it.

Read the full file on GitHub · 274 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. yesterday First seen · 274 lines · 146 tokens per session scan A 6ff72a38c4b4

Subscribe to this mod's changes

commit-message is a skill published in the GitHub repository chucklever/cel-kdev (2 stars, last pushed 4d ago), licensed MIT. It adds 146 tokens to every session and 2,946 once invoked, about $0.0007 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.

Related

Other skills, from other repositories

systematic-debugging

Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.

obra/superpowers · 21 tokens

next-cache-components-adoption

Turn on Cache Components in a Next.js app and resolve the blocking routes it surfaces. Use when the user wants to enable, adopt, or migrate to Cache Components, flip the cacheComponents flag, work through a flood of blocking-prerender / instant validation errors, run the cache-components-instant-false codemod, or…

vercel/next.js · 95 tokens

babysit-pr

Babysit a GitHub pull request after creation by continuously polling review comments, CI checks/workflow runs, and mergeability state until the PR is merged/closed or user help is required. Diagnose failures, retry likely flaky failures up to 3 times, auto-fix/push branch-related issues when appropriate, and keep…

openai/codex · 114 tokens

imagegen

Generate or edit raster images when the task benefits from AI-created bitmap visuals such as photos, illustrations, textures, sprites, mockups, or transparent-background cutouts. Use when Codex should create a brand-new image, transform an existing image, or derive visual variants from references, and the output…

openai/codex · 113 tokens

cpu-profile-analysis

Analyze V8/Chrome CPU profiles (.cpuprofile) and DevTools trace files (Trace-.json). Use when: profiling performance, investigating slow functions, comparing code paths, finding bottlenecks, analyzing timeToRequest, understanding call trees from sampling profiler data, analyzing layout/paint/rendering, investigating…

microsoft/vscode · 71 tokens

next-cache-components-optimizer

Drive a Next.js route to instant navigation by setting up an agentic loop, under Cache Components / PPR, on initial load (hard navigation) and client-side navigation (soft navigation). Encode the goal as a failing @next/playwright instant() e2e and work it to green, one verified route at a time; the shipped test then…

vercel/next.js · 170 tokens