commit-lint

commit-lint is a skill for Claude Code, Codex from bestdeejay-design/agent-skills. It costs 149 tokens per session (2,232 once invoked), scanned A, original, MIT.

A read-only checker for git commit messages that tests Conventional Commits, a format such as “fix: correct login error.” It reports which commits follow the rules and which break them.

In plain words
What is it for?
Use it to check one or more repositories, or commit lines supplied through standard input, without changing the history.
Why use it?
It catches inconsistent commit messages before they interfere with release notes or version calculations.

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/bestdeejay-design/agent-skills/commit-lint
Any agent
npx skills add bestdeejay-design/agent-skills --skill commit-lint
Clone the repo
git clone --depth 1 https://github.com/bestdeejay-design/agent-skills

Made for: Claude Code, Codex.

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 commit-lint

README.md
[![agentmods](https://agentmods.dev/badge/skills/bestdeejay-design/agent-skills/commit-lint.svg)](https://agentmods.dev/skills/bestdeejay-design/agent-skills/commit-lint)
Your own site
<a href="https://agentmods.dev/skills/bestdeejay-design/agent-skills/commit-lint"><img src="https://agentmods.dev/badge/skills/bestdeejay-design/agent-skills/commit-lint.svg" alt="Measured on agentmods" height="20"></a>
Per session 149 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,232 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 $0.00149 $0.02232
Opus 5 $0.00075 $0.01116
Sonnet 5 $0.00030 $0.00446
Haiku 4.5 $0.00015 $0.00223

Measured 4d ago against content hash 3cbeeee0ab6d, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

commit-lint 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 4d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/commit_lint.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

skills/commit-lint/SKILL.md · 180 lines

How it starts

The opening of the file, as written. The whole thing — 180 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Commit Lint — Conventional Commits validator

Load this skill when you need to validate git commit messages against Conventional Commits and produce a report of what passes and what violates the convention. It is the quality gate of the commit pipeline: commit-message-writer writes the commits, commit-lint checks them, version-bumper derives the next version from the clean history.

The tool is read-only and offline: it never modifies commits, never writes files, and makes no network calls. It reads git log of a real repository (via subprocess), parses each commit header as <type>(<scope>)?(!)?: <subject>, and reports per-commit type/scope/subject plus every violated rule. For testability the commit list can be fed from stdin (--stdin, one commit per line) — no git repository required.


The linter script

scripts/commit_lint.py — pure Python 3 stdlib (no dependencies).

Mode Command
Auto-detect repo from cwd python3 commit_lint.py
Explicit repo path python3 commit_lint.py /path/to/repo
Multiple repos python3 commit_lint.py repo1 repo2 repo3
Override auto-detection python3 commit_lint.py --repo /path/to/repo
Limit to N latest commits python3 commit_lint.py --repo . --count 50
No git needed (stdin) printf 'feat: ok\n' | python3 commit_lint.py --stdin
Machine-readable output python3 commit_lint.py --repo . --json

Rules enforced (Conventional Commits v1.0.0)

Violation Rule Default
missing-type no <type>(<scope>)?(!)?: <subject> prefix found
invalid-type type not in the allowed set feat fix docs style refactor test perf ci chore build revert
type-case type must be lowercase (Feat: is a violation)
scope-invalid scope must be non-empty and contain no spaces
empty-subject no description after <type>:
space-after-colon exactly one space required after :
subject-too-long subject longer than max 50 chars (--max-subject)
header-too-long full header longer than max 100 chars (--max-header)
subject-case subject must start with a lowercase letter or digit on (--no-subject-case disables)
trailing-dot subject must not end with . on (--no-trailing-dot disables)
trailing-space subject must not end with whitespace
body-line-too-long body line longer than max 72 chars (--max-body-line)

Read the full file on GitHub · 180 lines

Files

What ships with it

3 files 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. 4d ago First seen · 180 lines · 149 tokens per session scan A 3cbeeee0ab6d

Subscribe to this mod's changes

commit-lint is a skill published in the GitHub repository bestdeejay-design/agent-skills (5 stars, last pushed yesterday), licensed MIT. It adds 149 tokens to every session and 2,232 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.