changelog-generator

name	changelog-generator
description	This skill should be used when preparing releases, writing app store updates, or maintaining a CHANGELOG.md. It parses conventional commits and outputs polished release notes.
allowed-tools	Bash, Read, Write, Edit
metadata	{"triggers":"changelog, release notes, CHANGELOG.md, git log, release preparation, conventional commits, app store update, version release","related-skills":"pr-review, documentation-generation, verification-before-completion","domain":"workflow","role":"specialist","scope":"analysis","output-format":"document"}
last-reviewed	2026-03-15

Iron Law: Never generate a changelog without reading actual git history or diff; always base entries on verified commits, not assumptions.

Changelog Generator Skill

Transform git commit history into polished, user-friendly changelogs. Works with any tech stack by auto-detecting the project structure.

High-Level Process

1. Detect project structure - Scan repo for platform markers (Java, Node, Python, Angular, Flutter, etc.) and build a platform label map
2. Determine commit range - Use tags, dates, or commit count. Ask user if unclear
3. Extract commits - Pull structured log: git log "$LAST_TAG"..HEAD --pretty=format:"%h|%ai|%an|%s" --no-merges
4. Categorize - Map conventional commit prefixes to user-facing categories (feat -> New Features, fix -> Bug Fixes, perf -> Performance). Skip refactor/test/chore/ci/build/style
5. Rewrite - Translate technical commits to user-friendly language. Lead with user benefit, strip jargon
6. Assemble - Format changelog for the target destination
7. Output - Write to CHANGELOG.md, GitHub Release, App Store, Slack, or internal format

For detailed step-by-step workflow (project detection scripts, commit parsing, categorization table, rewriting rules, assembly format) -> Read reference/changelog-workflow.md

For output format examples (App Store, Keep a Changelog, internal/technical, Slack/email) -> Read reference/changelog-workflow.md

Key Rules

• Read CLAUDE.md first if it exists -- it describes the project's tech stack and conventions
• Always include: feat:, fix:, perf:, security:, BREAKING CHANGE
• Always skip: refactor:, test:, chore:, ci:, build:, style:
• Non-conventional commits: categorize by intent, include under "Improvements" if ambiguous
• Multi-platform repos: prefix entries with platform label (e.g., Mobile App, Web App, Backend)
• Single-platform repos: skip the label entirely

Output Destinations

Destination	Action
CHANGELOG.md	Prepend to existing file (newest on top)
GitHub Release	Output as Markdown block ready to paste
App Store	Shorter format, no emoji, plain language, max 4000 chars
Slack / Email	Condensed summary with highlights only
Internal	Include technical details and commit hashes

Automation Tip

Suggest to the user: add a pre-release hook or CI step that runs this skill automatically when tagging a new version. Pair with the /changelog command for quick manual runs.

For tool configuration (cliff.toml, release.config.js, GitHub Actions release workflow) -> Read reference/changelog-automation-tools.md

Anti-Patterns

❌ Don't invent entries. Never add changelog items that have no backing commit. Every line must map to a real commit hash.

❌ Don't expose internals. "Refactored UserService to use factory pattern" is not user-facing. Rewrite as the benefit, or skip it.

❌ Don't copy commit messages verbatim. Raw messages like fix: typo in auth handler become noise. Rewrite to user-facing language or drop it.

❌ Don't include chore/ci/test/build commits in user-facing changelogs. They belong in internal/technical format only.

Error Handling

Empty git log (no commits in range):

git log "$LAST_TAG"..HEAD --oneline
# returns nothing

Stop. Do not generate an empty changelog. Report: "No commits found between $LAST_TAG and HEAD. Confirm the tag name or provide a date range."

git log command fails (no tags exist):

git describe --tags --abbrev=0
# fatal: No names found, cannot describe anything.

Fall back to full history: git log --pretty=format:"%h|%ai|%an|%s" --no-merges. Warn the user that the range is unbounded (all commits since repo init).

No conventional commits found: Verify commit messages follow type: prefix format. Fall back to manual changelog if history is inconsistent.

Ambiguous scope: When a commit touches multiple features, split the changelog entry by affected area.