Commit Message

---
name: commit-message
model: haiku
description: "Reviews working-tree changes, then drafts a Conventional Commits title/body and states the semantic-release version bump a single such commit would imply. Also notes which defensive-code categories were touched. Use when the user wants to commit recent work, prepare a Conventional Commits message, or asks for semantic-release / semver-consistent messaging before git commit."
---

<!-- story: e82s02 -->

# Commit Message
> **HARD GATE** — **HARD GATE** — Commits must follow Conventional Commits spec (type(scope): description). Do NOT use vague messages like 'fix' or 'updates.' The message must explain the 'why,' not the 'what.'


## Modes

- Default: standard Conventional Commits message
- --fix-type: Forces type=fix. Use when commit type is unambiguous.

## What "last chat" means

- **Primary source of truth:** Read `state.yaml` `vcs.kind`. Git uses `git status`, `git diff`, and `git diff --cached`; Jujutsu uses `jj status`, `jj diff`, and `jj log -r @`. Run in the repo root.
- **Context:** use the current conversation to summarize *intent* and to spot **breaking** API/behavior changes that diff alone may not show.
- If the user tracks a session baseline (e.g. branch, tag, or `git stash create` at start), you may `git diff <baseline>..HEAD` plus uncommitted diffs; otherwise use only the index and working tree.

## Quick workflow

1. **Inventory** — List changed paths; group by feature vs chore vs docs vs test-only.
2. **Decide commit shape** — One atomic commit is ideal. If the diff mixes unrelated concerns, recommend **multiple commits** (each with its own type/scope) before suggesting one message.
3. **Classify for semantic release** — `fix` → patch, `feat` → minor, **breaking** → major.
4. **Write the message** — `type(optional-scope)!: description` (see [REFERENCE.md](../../../skills/commit-message/REFERENCE.md#message-format)). Use `!` or a `BREAKING CHANGE:` footer when behavior contracts change.
5. **Note defensive-code categories touched** — from CONVENTIONS.md: Rate limit | Retry with backoff | Circuit breaker | Timeout | Graceful degradation
6. **Note fix-ratio contribution** — Each `fix:` commit counts toward `metrics.commit_ratio.fix` in `specs/state.yaml`. After `release-branch`, `session-state` recalculates the ratio automatically. A high fix rate (>30%) triggers a deploy + smoke-test suggestion.
7. **Deliver** — Output:
   - Proposed **full commit message** (title + optional body + footers).
   - **Release bump** this commit would drive: `patch` | `minor` | `major` | `none`.
   - Optional native command: Git `git commit -m`; Jujutsu `jj commit -m`. Never omit `-m` or run destructive commands unless asked.

## Checklist before finalizing

- [ ] Type matches the **dominant** user-visible outcome (`feat` vs `fix` vs `perf`, etc.).
- [ ] **Scope** is a short noun in parentheses if it helps (e.g. `fix(api): …`).
- [ ] Breaking changes are explicit (`!` and/or `BREAKING CHANGE:` in the body/footer).
- [ ] Description is imperative, lowercase start after the prefix, no trailing period in the title line.
- [ ] **NO `Co-authored-by` or `Co-Authored-By` footers** — P1 rule (CONVENTIONS.md § Git Attribution). All commits must appear as if authored solely by the human user. The git hook and `land-branch.sh` both block these.

## When not to invent a bump

If the repo uses a custom `@semantic-release/commit-analyzer` preset, note that your bump is **heuristic** and they should match `.releaserc` / `release.config.*`. See [REFERENCE.md](../../../skills/commit-message/REFERENCE.md#custom-repositories).

## Further reading

- [REFERENCE.md](../../../skills/commit-message/REFERENCE.md) — Message shape, footers, release mapping, squashing notes.



## Handoff

Gate: READY -> next: release-branch
Writes: state.yaml handoff.next_skill = release-branch

---

# Conventional Commits + semantic-style release (reference)

## Message format

From [Conventional Commits 1.0.0](https://www.conventionalcommits.org/en/v1.0.0/#specification):

```text
<type>[optional scope][optional !]: <description>

[optional body]

[optional footer(s)]
```

- **Scope:** parenthesized noun, e.g. `feat(parser): …`.
- **Breaking:** `!` before `:` (e.g. `feat(api)!: …`) and/or footer `BREAKING CHANGE: description` (token must be uppercase per spec for that footer name).
- **Description:** short summary; body explains *why* or migration steps.

Common **types** (not exhaustive): `feat`, `fix`, `docs`, `style`, `refactor`, `perf`, `test`, `build`, `ci`, `chore` — as in [Angular / commitlint conventions](https://github.com/conventional-changelog/commitlint).

## Advanced Specification Patterns

### Reverts
If the commit reverts a previous commit, it should begin with `revert:`, followed by the header of the reverted commit. In the body, it should say: `This reverts commit <hash>.`.

```text
revert: feat(api): add user endpoint

This reverts commit 676104e.
```

### Breaking Changes
A breaking change can be signaled by:
1.  A **`BREAKING CHANGE:`** footer (must be uppercase, at the start of the footer). This is the **most compatible** way to trigger a Major release in `semantic-release` (Angular preset).
2.  A **`!`** after the type/scope: `feat(api)!: change user response shape`.

**Pro-tip:** For maximum compatibility with all tooling (older and newer), use BOTH the `!` and the `BREAKING CHANGE:` footer.

### Footers (Tokens & Values)
Footers follow the same `Token: value` pattern as Git Trailers. Common tokens:
- `Refs: #123`
- `See-also: docs/ADR-001.md`
- `Signed-off-by: Name <email>`

**Multi-line footers:** If a footer value spans multiple lines, each subsequent line must be indented.

### Squashing & History
When using `gh pr merge --squash`, the PR title is usually used as the commit subject. 
- **PR Title:** MUST follow `<type>(<scope>): <description>`
- **PR Body:** Content will be moved to the commit body.

## Release Type Mapping (Default Angular Preset)

This table reflects the **out-of-the-box** behavior of `semantic-release` using the `@semantic-release/commit-analyzer` default (Angular) rules.

| Commit pattern | Release | Notes |
|----------------|---------|-------|
| `fix:` | **Patch** | Bug fixes |
| `feat:` | **Minor** | New features |
| `perf:` | **Patch** | Performance improvements |
| `any type` + `BREAKING CHANGE:` footer | **Major** | **Mandatory** for Major version bumps in default configs. |
| `any type!:` (exclamation mark) | **Major** | Supported by modern CC parsers, but use footer for max safety. |
| `docs:`, `chore:`, `test:`, `ci:`, `refactor:`, `style:` | **None** | Does not trigger a new release by default. |

> **Warning:** While `refactor:` and `style:` improve code, they do NOT trigger a release in the default Angular preset. Use `fix:` if a refactor also fixes a bug, or `feat:` if it adds new behavior.

## Custom Repositories

- Read `release.config.js`, `.releaserc`, or `package.json` → `release` / `semantic-release` config.
- The **@semantic-release/commit-analyzer** preset may map types differently; prefer **their** rules when they conflict with this reference.

## Squash and PR titles

- If the team squashes on merge, the **PR title** often becomes the single squashed commit subject — it should still follow `type(scope): description` for tooling.
- `revert:` type and `Refs:` footers are valid patterns; revert handling varies by [tooling](https://www.conventionalcommits.org/en/v1.0.0/#specification).

## Links

- [Conventional Commits — specification](https://www.conventionalcommits.org/en/v1.0.0/#specification)
- [semantic-release — README (commit format & flow)](https://github.com/semantic-release/semantic-release#commit-message-format)
- Automation and docs align with [semantic-release](https://github.com/semantic-release/semantic-release) upstream; a fork may be substituted without changing this guidance.