# Git Commit Composer

> Generate conventional commit messages from staged git changes. Use when asked to compose a commit message, write a commit, generate conventional commits, or describe staged changes. Use when this capability is needed.

- Skill: `tomevault-io/git-commit-composer` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add tomevault-io/git-commit-composer`
- Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/git-commit-composer/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: tomevault-io (https://skillmd.com/u/tomevault-io)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/tomevault-io/git-commit-composer

---


# Git Commit Composer

Before generating any output, read `config/defaults.md` and adapt all patterns, imports, and code examples to the user's configured stack.

## Process

1. Run `git diff --cached` to read staged changes. If nothing is staged, run `git diff` and inform the user to stage changes first.
2. Analyze the diff to determine: what changed, why it changed, and the impact.
3. Classify the change type and generate a commit message following Conventional Commits.
4. If the diff contains multiple unrelated changes, suggest splitting into separate commits.

## Commit Message Format

```
<type>(<scope>): <description>

[optional body]

[optional footer(s)]
```

### Types

| Type | When to use |
|---|---|
| `feat` | New feature or capability |
| `fix` | Bug fix |
| `refactor` | Code change that neither fixes a bug nor adds a feature |
| `test` | Adding or updating tests |
| `docs` | Documentation changes only |
| `style` | Formatting, semicolons, whitespace (no logic change) |
| `perf` | Performance improvement |
| `chore` | Build, tooling, dependency updates, config changes |
| `ci` | CI/CD configuration changes |
| `build` | Build system or external dependency changes |
| `revert` | Reverts a previous commit |

### Scope

Derive the scope from the primary area of change:

- File/module name: `feat(auth): add JWT refresh token rotation`
- Feature area: `fix(checkout): prevent double charge on retry`
- Layer: `refactor(api): extract validation middleware`

Omit scope if the change spans many unrelated areas.

### Description Rules

- Use imperative mood: "add" not "added" or "adds"
- No capitalized first letter
- No period at the end
- Under 72 characters total (including type and scope)
- Describe what the change does, not what was wrong

**BAD:**
```
fix: Fixed the bug where users couldn't log in.
feat: Added new validation to the form
chore: updated dependencies
```

**GOOD:**
```
fix(auth): prevent login failure when session cookie is expired
feat(form): add email format validation to signup form
chore(deps): bump next from 14.1.0 to 14.2.0
```

### Body

Add a body when the description alone doesn't explain the "why":

```
fix(api): return 404 instead of 500 for missing resources

Previously, querying a non-existent user threw an unhandled
PrismaClientKnownRequestError, resulting in a 500 response.
Now the error is caught and mapped to a proper 404.
```

### Breaking Changes

Use `!` after the type/scope and add a `BREAKING CHANGE` footer:

```
feat(api)!: change user endpoint response format

BREAKING CHANGE: GET /api/users now returns { data: User[], meta: {...} }
instead of a plain User[] array. All clients must update their response parsing.
```

## Multi-Change Detection

When the diff modifies unrelated areas, suggest splitting:

```
## Suggested Commits

The staged changes contain 3 unrelated modifications. Recommend splitting:

1. `feat(auth): add password reset endpoint`
   Files: `app/api/auth/reset/route.ts`, `lib/email.ts`

2. `fix(ui): correct date format on invoice page`
   Files: `components/InvoiceTable.tsx`

3. `chore(deps): bump zod from 3.22.0 to 3.23.0`
   Files: `package.json`, `package-lock.json`

To split, unstage all and re-stage per commit:
git reset HEAD .
git add app/api/auth/reset/route.ts lib/email.ts && git commit
git add components/InvoiceTable.tsx && git commit
git add package.json package-lock.json && git commit
```

## Dependency Updates

For dependency changes, include the version bump:

```
chore(deps): bump next from 14.1.0 to 14.2.0
chore(deps-dev): add vitest 2.0.0 and @testing-library/react 16.0.0
fix(deps): pin prisma to 5.19.0 to resolve migration bug
```

## Output Format

```
## Commit Message

[The generated commit message in a code block]

### Analysis
- **Type**: [type] — [reason for classification]
- **Scope**: [scope] — [derived from]
- **Files changed**: [count]
- **Insertions/deletions**: +[n] / -[n]
```

---
> Converted and distributed by [TomeVault](https://tomevault.io/claim/nembie) — claim your Tome and manage your conversions.
<!-- tomevault:4.0:skill_md:2026-04-13 -->