commit-message

name	commit-message
description	This skill should be used when the user asks to "create a commit", "generate commit message", "commit changes", "make a commit", mentions "conventional commits", or discusses commit message formatting. Provides guided workflow for creating properly formatted commit messages with line length validation and required trailers.
version	0.2.0

Conventional Commit Message Creation

Create properly formatted conventional commit messages following project standards with line length validation and required trailers.

Purpose

Generate commit messages that:

• Follow conventional commits format (type(scope): description)
• Use component names or GitHub issue numbers as scope
• Respect line length limits (50 for subject, 72 for body)
• Include required trailers (Signed-off-by, Assisted-by)
• Match Tekton commit message standards

Quick Workflow

1. Analyze changes: Run git status and git diff to understand modifications
2. Determine scope: Use component name from changed files, or GitHub issue number if available
3. Generate message: Create conventional commit message with proper formatting
4. Add trailers: Include Signed-off-by and Assisted-by trailers
5. Confirm with user: Display message and wait for approval before committing

CRITICAL: Never commit without explicit user confirmation.

Conventional Commit Format

Structure

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

[optional body]

Signed-off-by: <name> <email>
Assisted-by: <model-name> (via <Tool>)

Type Selection

Choose the appropriate commit type based on changes:

Type	Description	Example
feat	New features	feat(storage): add Archivista backend
fix	Bug fixes	fix(signing): resolve KMS race condition
docs	Documentation	docs(README): update installation steps
refactor	Code refactoring	refactor(formats): simplify SLSA builder
test	Test changes	test(e2e): add OCI storage tests
chore	Maintenance	chore(deps): update go dependencies
build	Build system	build(Makefile): add vendor target
ci	CI/CD changes	ci(github): add golangci-lint action
perf	Performance	perf(reconciler): reduce requeue latency
style	Code style	style(format): run goimports
revert	Revert commit	revert: undo breaking config change

For complete type reference, see references/commit-types.md.

Scope Rules

Priority 1: Component from changed files

Analyze staged files to identify the primary component:

git diff --cached --name-only

File pattern	Scope	Example commit
pkg/chains/signing/*	signing	fix(signing): resolve x509 cert issue
pkg/chains/storage/*	storage	feat(storage): add PubSub backend
pkg/chains/formats/*	formats	refactor(formats): simplify SLSA v2
pkg/reconciler/taskrun/*	taskrun	fix(taskrun): handle nil status
pkg/reconciler/pipelinerun/*	pipelinerun	feat(pipelinerun): add deep inspection
pkg/config/*	config	feat(config): add new signing key
pkg/artifacts/*	artifacts	refactor(artifacts): simplify extraction
cmd/*	controller	feat(controller): add new flag
docs/*	docs or filename	docs(config): update signing options
test/*	component being tested	test(storage): add GCS tests
Root files	filename	chore(Makefile): add lint target
AGENTS.md, CLAUDE.md	docs	docs(AGENTS.md): update conventions

Priority 2: GitHub issue number (optional)

If the work is tracked in a GitHub issue and the user provides one, it can be used as the scope:

Fixes #123

Add Fixes #NNN or Closes #NNN in the commit body (not the scope).

Priority 3: Ask user

If changed files span multiple components or scope is unclear, ask the user which component is the primary focus.

Line Length Requirements

Subject Line

• Target: 50 characters maximum
• Hard limit: 72 characters (Tekton community standard)
• Format: type(scope): description counts toward limit
• Tips: Use present tense, no period at end

Body

• Wrap at 72 characters per line
• Blank line required between subject and body
• Content: Explain why, not what (code shows what)

Required Trailers

Signed-off-by

Always include: Signed-off-by: <name> <email>

This certifies the Developer Certificate of Origin (DCO) — required by tektoncd upstream.

Detection priority order:

1. Environment variables: $GIT_AUTHOR_NAME and $GIT_AUTHOR_EMAIL
2. Git config: git config user.name and git config user.email
3. If neither configured, ask user to provide details

For complete detection logic, see references/trailer-detection.md.

Assisted-by

Always include: Assisted-by: <model-name> (via <Tool>)

Use the actual model name and tool name.

User Confirmation Requirement

CRITICAL RULE: Always ask for user confirmation before executing git commit.

1. Generate the commit message following all rules above
2. Display the complete message to the user
3. Ask: "Should I commit with this message? (y/n)"
4. Wait for user response
5. Commit only if user confirms

Commit Execution

Use heredoc format for proper multi-line handling:

git commit -m "$(cat <<'EOF'
feat(storage): add Archivista backend

Enable storing attestations in Archivista for improved
discoverability and querying.

Signed-off-by: Developer Name <[e-mail]>
Assisted-by: <Model name> (via <Tool>)
EOF
)"

Never use:

• --no-verify (skips pre-commit hooks)
• --no-gpg-sign (skips signing)
• --amend (unless explicitly requested and safe)

Format standards

Follow Tekton commit message standards:

• Conventional commit format (type(scope): description)
• Subject line: target 50 characters, hard limit 72
• Body lines wrapped at 72 characters
• Required Signed-off-by trailer (DCO)
• No trailing punctuation on the subject

Auto-Detection Summary

1. Run git status and git diff for staged/unstaged changes
2. Identify primary component from staged file paths
3. If scope unclear, ask user
4. Analyze staged files to determine commit type
5. Detect author info from environment variables or git config
6. Ensure subject line is ≤50 characters (max 72)
7. Wrap body text at 72 characters per line
8. Add required trailers (Signed-off-by and Assisted-by)
9. Display message and ask for user confirmation
10. Only commit after receiving confirmation

Additional Resources

• references/commit-types.md - Complete commit type reference with descriptions
• references/trailer-detection.md - Author detection logic and priority order