Types

Type	Description	Example
`feat`	New feature	`feat: add user authentication`
`fix`	Bug fix	`fix: resolve login timeout issue`
`docs`	Documentation only	`docs: update API reference`
`style`	Code style (formatting, semicolons)	`style: format with prettier`
`refactor`	Code change that neither fixes nor adds	`refactor: extract validation logic`
`perf`	Performance improvement	`perf: optimize database queries`
`test`	Adding or fixing tests	`test: add unit tests for auth`
`chore`	Maintenance tasks	`chore: update dependencies`
`ci`	CI/CD changes	`ci: add GitHub Actions workflow`
`build`	Build system changes	`build: upgrade webpack to v5`

Scope (Optional)

Indicates the section of the codebase:

feat(auth): add OAuth2 support
fix(api): handle null response
docs(readme): add installation steps

Commit Message Guidelines

Good Commit Messages

feat: add password strength indicator

- Show visual feedback for password strength
- Validate minimum requirements
- Display helpful suggestions

Closes #123

fix: prevent duplicate form submissions

Add debounce to submit button to prevent
multiple API calls when user clicks rapidly.

Bad Commit Messages

# Too vague
fix: fix bug

# Not descriptive
update code

# Too long for subject
feat: add new feature that allows users to reset their password by clicking a link sent to their email

Rules

Rule	Example
Subject line max 50 chars	`feat: add login page`
Use imperative mood	`add` not `added` or `adds`
No period at end of subject	`fix: resolve issue` not `fix: resolve issue.`
Blank line between subject and body	See examples above
Body wraps at 72 chars	For readability in terminals
Explain what and why, not how	Code shows how

Workflow

Before Committing

# Check status
git status

# Review changes
git diff

# Review staged changes
git diff --staged

Staging Files

# Stage specific files
git add path/to/file.js

# Stage all changes in directory
git add src/

# Stage all tracked files
git add -u

# Interactive staging (select hunks)
git add -p

Creating the Commit

# Commit with message
git commit -m "feat: add user profile page"

# Commit with body (opens editor)
git commit

# Commit with multi-line message
git commit -m "feat: add user profile page" -m "Includes avatar upload and bio editing"

Atomic Commits — Granularity Rules

Each commit MUST represent one logical change. When the user asks to commit, analyze git diff and split into multiple commits if the changes span different concerns.

How to Decide

Ask: "If I needed to revert this, would I want to revert ALL of these changes together?" If the answer is no, split them.

Signal	Action
Changes touch different domains/features	Split by domain
Mix of infra + feature code	Separate commits
New dependency + feature using it	Can be one commit (dependency serves the feature)
Tests + implementation they test	Same commit (they're one logical unit)
Formatting/linting + feature changes	Separate commits
Migration + repository + domain changes	Split if they're independently meaningful

Commit Order

When splitting, commits MUST be ordered so the repo compiles and passes tests at every point:

Infrastructure/config changes first (dependencies, migrations, configs)
Domain/core logic second
Application/service layer third
Transport/handler layer last
Documentation/chore changes independently

Example — What NOT to Do

# BAD: One giant commit mixing everything
git add -A
git commit -m "feat(auth): add multi-role support, postgres, gateway proxy, docker-compose"

Example — Correct Granularity

# 1. Domain change
git add api/auth/internal/auth/domain/
git commit -m "feat(auth): refactor user entity from single role to multi-role

- Change Role field to []Role with HasRole/AddRole/RemoveRole
- Add NewRoles validator with dedup and ErrNoRoles
- Update domain tests for multi-role scenarios"

# 2. Infrastructure adapters
git add api/auth/internal/auth/infrastructure/ api/auth/migrations/ api/auth/go.*
git commit -m "feat(auth): add PostgreSQL repository with pgx and sqlc

- Add user_roles migration and sqlc-generated queries
- Implement PostgresUserRepository and PostgresTokenBlacklist
- Add DB_PROVIDER switch in main.go (memory/postgres)"

# 3. Independent service change
git add api/gateway/
git commit -m "feat(gateway): add reverse proxy forwarding to auth service"

# 4. DevOps/tooling
git add docker-compose.yml Makefile skills/
git commit -m "chore: add docker-compose and local dev workflow"

When a Single Commit Is Fine

All changes serve ONE purpose (e.g., a bug fix touching 5 files)
A small feature fully contained in one layer
Pure refactoring with no behavior change

Safety Rules

Never Do

Action	Risk
`git commit --amend` after push	Rewrites public history
`git push --force` to shared branches	Overwrites others' work
Commit secrets/credentials	Security breach
Commit large binary files	Bloats repository

Amend Safely

Only amend if ALL conditions are met:

Commit has NOT been pushed
You are the author
No one else has based work on it

# Safe: amend unpushed commit
git commit --amend -m "feat: corrected message"

# Check if pushed
git status  # Shows "Your branch is ahead of..."

Files to Never Commit

# Secrets
.env
.env.local
*.pem
credentials.json
secrets.yaml

# IDE
.idea/
.vscode/
*.swp

# Dependencies
node_modules/
vendor/
__pycache__/

# Build artifacts
dist/
build/
*.pyc

Commands Reference

# View recent commits
git log --oneline -10

# View commit details
git show <commit-hash>

# Undo last commit (keep changes staged)
git reset --soft HEAD~1

# Undo last commit (keep changes unstaged)
git reset HEAD~1

# Discard last commit entirely (DANGEROUS)
git reset --hard HEAD~1

# Create commit with sign-off
git commit -s -m "feat: add feature"

# Create commit skipping hooks (use sparingly)
git commit --no-verify -m "wip: work in progress"

Checklist

Changes are related and atomic (one logical change)
Commit message follows conventional format
Subject line is under 50 characters
No secrets or credentials included
Tests pass (if applicable)
Linting passes (if applicable)

git-commit

When to Use

Conventional Commits Format