Commit

Agent Delegation

You MUST delegate the review of atomic commit groupings and the evaluation of mixed-concern file changes to the principal-engineer sub-agent to ensure high-stakes technical decisions are correctly reflected in the git history.

When to Use This Skill

• After completing work that spans multiple logical changes
• When working tree has mixed changes (features, fixes, refactors)
• To ensure clean, reviewable git history
• Before creating a pull request

Pre-flight Checks

Before analysis:

1. Working tree state: Run git status --porcelain
2. Conflict markers: Run git diff --check
3. No rebase/merge in progress: Verify no .git/MERGE_HEAD or .git/REBASE_HEAD exists
4. GPG signing: All commits MUST use git commit -S

Staging Strategy

Mixed-Concern Files (STOP AND ASK)

If a single file contains changes for multiple logical units (e.g., a bug fix AND a refactor) that requires interactive staging:

1. Analyze Hunks: Carefully review the git diff for the file to identify individual hunks.
2. Determine Sequence: Create a sequence of 'y' (yes) or 'n' (no) for each hunk, corresponding to the logical unit you are currently preparing to commit.
3. STOP and Instruct:
   • DO NOT attempt to run git add -p yourself.
   • DO output: "File <filename> has mixed changes. Please run git add -p <filename> and apply the following sequence: y, n, y... (corresponding to the hunks for [logical unit])."
4. Wait: Explicitly wait for the user to confirm they have staged the correct hunks before creating the commit.

Commit Message Standards

• Subject: Conventional Commit format: <type>: <Capitalized imperative verb phrase>, 50 chars max, no period
• Body: Required. Blank line after subject, wrapped at 72 chars. Explain why.

Workflow

1. Analyze current state:

   • Check git status to see all staged and unstaged changes
   • Review git diff to understand what changed

2. Group changes into atomic units:

   • Each group should represent one logical change (feature, fix, refactor, docs, etc.)
   • Group related files and hunks together
   • Keep changes that depend on each other in the same commit or note the dependency

3. For each group, provide:

   • List of files/hunks to stage
   • Commit message following project conventions
   • Brief rationale for the grouping

4. Note dependencies:

   • If commits must be applied in a specific order, document this
   • Identify any commits that could be applied independently

5. Execute commits:

   • Stage and commit each group in the appropriate order
   • Proceed unless there are questions or ambiguities

Optional Focus

You can provide a focus to filter which changes to consider:

• "frontend only" - only consider frontend-related changes
• "exclude tests" - skip test file changes
• "api changes" - focus on API-related files
• Any other relevant filter for the codebase

Constraints

• NEVER push to remote - this skill only creates local commits
• Atomic commits - each commit should be a single logical unit that could be reverted independently
• Respect project conventions - match existing commit message style in the repository
• Ask before proceeding - if grouping is ambiguous, ask for clarification rather than guessing

Examples

Example: Mixed Working Tree

Situation: Working tree has changes to API handler, its tests, a bug fix in an unrelated util, and a README update.

git status output:

modified:   internal/api/users.go
modified:   internal/api/users_test.go
modified:   internal/util/strings.go
modified:   README.md

Proposed commit groups:

Group 1: Bug fix (independent)

Files: internal/util/strings.go
Message: fix: Handle empty string edge case in TrimSafe

Rationale: Standalone fix, no dependencies on other changes

Group 2: Feature (with tests)

Files: internal/api/users.go, internal/api/users_test.go
Message: feat: Add email validation to user creation endpoint

Rationale: Handler and its tests belong together as one logical unit

Group 3: Documentation (independent)

Files: README.md
Message: docs: Add API usage examples

Rationale: Documentation update, independent of code changes

Suggested order: Group 1 → Group 2 → Group 3 (no strict dependencies)

Begin by running git status and git diff to analyze the current working tree state.