changelog-generator

Changelog Generator

Generate structured, user-facing changelogs from git commit history.

Workflow

Step 1 — Gather commits

Determine the commit range from the user's request, then fetch commits:

# Between tags/versions
git log v1.2.0..v1.3.0 --oneline --no-merges
# Since a date
git log --since="2024-03-01" --oneline --no-merges
# Since last tag (default when no range given)
git log "$(git describe --tags --abbrev=0)"..HEAD --oneline --no-merges

If there are no tags and no range specified, ask the user for a date or count.

Step 2 — Categorize each commit

Apply these rules based on the commit message prefix:

Prefix / pattern	Category
feat: feature:	New Features
fix: bugfix:	Bug Fixes
perf:	Performance
BREAKING CHANGE or !: suffix	Breaking Changes
security: vuln:	Security
docs: test: ci: chore: refactor: style: build:	Skip (internal)

For non-conventional messages, infer category from content. Exclude purely internal commits (test infra, CI config, linting, dependency bumps with no user impact).

Step 3 — Rewrite for a non-technical audience

Transform each kept commit into a clear, benefit-focused sentence:

• Strip scope tags like (api): or (auth):
• Expand abbreviations and jargon
• Lead with the user-visible outcome, not the implementation
• Use present tense: "Add", "Fix", "Improve"
• One sentence per entry

Example: fix(auth): race condition in token refresh becomes "Fix an issue where sessions could expire unexpectedly during use."

Step 4 — Format the output

# Changelog — vX.Y.Z (YYYY-MM-DD)

## Breaking Changes
- [entry]

## New Features
- [entry]

## Improvements
- [entry]

## Bug Fixes
- [entry]

## Security
- [entry]

Omit any empty section. Order: breaking changes, features, improvements, fixes, security. If the repo already has a CHANGELOG.md or CHANGELOG_STYLE.md, match its existing conventions instead.

Step 5 — Validate before presenting

1. Confirm no internal-only commits leaked through
2. Confirm every entry is understandable without reading source code
3. Confirm date and version label are correct
4. Write to CHANGELOG.md (prepend above existing content) or print inline, based on the user's request