Changelog Automation

Changelog Automation

Automated versioning and changelog generation using Changesets (monorepos) or semantic-release (single packages) with conventional commits.

Philosophy

Manual changelog maintenance is error-prone and time-consuming. Automate version bumping, changelog updates, and release notes generation based on commit history or explicit change declarations.

Two proven approaches:

1. Changesets: PR-based workflow where developers declare intent in separate files (best for monorepos)
2. Semantic-release: Commit-based workflow using conventional commits (best for single packages)

Both enforce Semantic Versioning (SemVer) and integrate seamlessly with CI/CD.

Semantic Versioning (SemVer)

All version numbers follow MAJOR.MINOR.PATCH format:

• MAJOR (1.0.0 → 2.0.0): Breaking changes, incompatible API changes
• MINOR (1.0.0 → 1.1.0): New features, backward-compatible additions
• PATCH (1.0.0 → 1.0.1): Bug fixes, backward-compatible fixes

Pre-release versions: 1.0.0-beta.1, 1.0.0-rc.2, 1.0.0-alpha.3

Changesets (Recommended for Monorepos)

Best for:

• Monorepos with multiple packages
• Teams that want explicit change declarations
• Projects where commit messages may not be reliable
• Gradual migration (works alongside existing processes)

Installation

# Install changesets
pnpm add -D @changesets/cli

# Initialize (creates .changeset directory and config)
pnpm changeset init

Configuration

// .changeset/config.json
{
  "$schema": "https://unpkg.com/@changesets/config@3.0.0/schema.json",
  "changelog": "@changesets/cli/changelog",
  "commit": false,  // Don't auto-commit changesets
  "fixed": [],      // Packages that must version together
  "linked": [],     // Packages that share version numbers
  "access": "public",  // or "restricted" for private packages
  "baseBranch": "main",
  "updateInternalDependencies": "patch",  // Bump dependent packages
  "ignore": ["@repo/config", "@repo/tsconfig"]  // Skip these packages
}

Workflow

1. Developer Creates Changeset

When making changes, developer creates a changeset file:

# Create a changeset (interactive prompts)
pnpm changeset

# Example prompts:
# ? Which packages would you like to include? ›
#   ◉ @repo/ui
#   ◯ @repo/utils
#   ◯ @repo/config
#
# ? What kind of change is this for @repo/ui? ›
#   ◯ patch  - Bug fixes, internal changes
#   ◉ minor  - New features, backward-compatible
#   ◯ major  - Breaking changes
#
# ? Please enter a summary for this change:
# › Added dark mode toggle component

This creates .changeset/random-name.md:

---
"@repo/ui": minor
---

Added dark mode toggle component with theme persistence

Commit the changeset file along with your code changes:

git add .changeset/random-name.md src/
git commit -m "feat: add dark mode toggle"
git push

2. Automated Release (GitHub Actions)

# .github/workflows/release.yml
name: Release

on:
  push:
    branches:
      - main

concurrency: ${{ github.workflow }}-${{ github.ref }}

jobs:
  release:
    name: Release
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Setup pnpm
        uses: pnpm/action-setup@v2

      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: 22
          cache: 'pnpm'

      - name: Install dependencies
        run: pnpm install --frozen-lockfile

      - name: Create Release Pull Request or Publish
        id: changesets
        uses: changesets/action@v1
        with:
          # Creates a "Version Packages" PR that bumps versions
          # Or publishes to npm if PR is merged
          publish: pnpm release
          commit: "chore: version packages"
          title: "chore: version packages"
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          NPM_TOKEN: ${{ secrets.NPM_TOKEN }}  # If publishing to npm

      - name: Send Slack notification
        if: steps.changesets.outputs.published == 'true'
        run: |
          echo "New version published!"
          # Add Slack webhook call here

What happens:

1. When changesets are merged to main, GitHub Action creates a "Version Packages" PR
2. This PR updates package.json versions and CHANGELOG.md for each package
3. When you merge the "Version Packages" PR, packages are published automatically
4. Git tags are created for each release

3. Manual Release

# Bump versions based on changesets
pnpm changeset version

# This updates package.json and CHANGELOG.md files
# Review changes, then commit
git add .
git commit -m "chore: version packages"

# Publish to npm
pnpm changeset publish

# Push tags to GitHub
git push --follow-tags

Package.json Scripts

{
  "scripts": {
    "changeset": "changeset",
    "changeset:version": "changeset version",
    "changeset:publish": "changeset publish",
    "release": "pnpm build && pnpm changeset publish"
  }
}

Advantages

✅ Explicit intent: Developers declare what changed and why ✅ Flexible timing: Create changeset anytime, release when ready ✅ Multi-package: Handles complex monorepo dependencies automatically ✅ PR-based: Fits naturally into PR workflow ✅ Gradual adoption: Can coexist with other versioning strategies ✅ Snapshot releases: Easy to create pre-release versions for testing

Example Changeset Files

Bug fix (patch):

---
"@repo/api": patch
---

Fixed race condition in authentication middleware

New feature (minor):

---
"@repo/ui": minor
"@repo/utils": patch
---

Added new `DataTable` component with sorting and filtering.
Updated `formatDate` utility to handle more formats.

Breaking change (major):

---
"@repo/api": major
---

BREAKING: Renamed `getUser()` to `fetchUser()` for consistency.
Migration: Replace all `getUser()` calls with `fetchUser()`.

Semantic-release (Recommended for Single Packages)

Best for:

• Single-package repositories
• Teams committed to conventional commits
• Fully automated release process
• Strict versioning discipline

Installation

pnpm add -D semantic-release @semantic-release/git @semantic-release/changelog

Configuration

// .releaserc.js
module.exports = {
  branches: ['main'],
  plugins: [
    // Analyze commits to determine version bump
    '@semantic-release/commit-analyzer',

    // Generate release notes
    '@semantic-release/release-notes-generator',

    // Update CHANGELOG.md
    '@semantic-release/changelog',

    // Update package.json version
    '@semantic-release/npm',

    // Commit updated files
    [
      '@semantic-release/git',
      {
        assets: ['package.json', 'CHANGELOG.md'],
        message: 'chore(release): ${nextRelease.version} [skip ci]\n\n${nextRelease.notes}',
      },
    ],

    // Create GitHub release
    '@semantic-release/github',
  ],
}

Conventional Commits

Semantic-release requires conventional commit format:

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

[optional body]

[optional footer]

Types that trigger releases:

• feat: New feature (bumps MINOR)
• fix: Bug fix (bumps PATCH)
• perf: Performance improvement (bumps PATCH)
• BREAKING CHANGE: in footer (bumps MAJOR)

Types that don't trigger releases:

• docs: Documentation changes
• style: Code style (formatting, semicolons)
• refactor: Code refactoring
• test: Adding tests
• chore: Maintenance tasks

Examples:

# Patch release (1.0.0 → 1.0.1)
git commit -m "fix: resolve authentication timeout issue"

# Minor release (1.0.0 → 1.1.0)
git commit -m "feat: add dark mode support"

# Major release (1.0.0 → 2.0.0)
git commit -m "feat: redesign API

BREAKING CHANGE: Renamed all `get*` methods to `fetch*` for consistency"

# No release
git commit -m "docs: update README with new examples"
git commit -m "chore: upgrade dependencies"

GitHub Actions Workflow

# .github/workflows/release.yml
name: Release

on:
  push:
    branches:
      - main

jobs:
  release:
    name: Release
    runs-on: ubuntu-latest

    permissions:
      contents: write  # To push tags and releases
      issues: write    # To comment on released issues
      pull-requests: write  # To comment on released PRs

    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          fetch-depth: 0  # Fetch all history for changelog
          persist-credentials: false

      - name: Setup pnpm
        uses: pnpm/action-setup@v2

      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: 22
          cache: 'pnpm'

      - name: Install dependencies
        run: pnpm install --frozen-lockfile

      - name: Build
        run: pnpm build

      - name: Release
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
        run: pnpm semantic-release

Advantages

✅ Fully automated: No manual version bumping or changelog updates ✅ Commit-based: Version determined from commit messages ✅ Consistent: Enforces conventional commits ✅ Immediate: Release happens automatically on merge to main ✅ Rich integrations: GitHub releases, npm publishing, Slack notifications

Disadvantages

⚠️ Strict commits required: Team must follow conventional commits religiously ⚠️ Less control: Version bump determined by commits, not explicit choice ⚠️ Single package focus: Monorepos need additional configuration ⚠️ Can't defer releases: Every merge to main triggers analysis

Enforcing Conventional Commits

Both approaches benefit from enforcing conventional commit format:

Commitlint Setup

# Install commitlint
pnpm add -D @commitlint/cli @commitlint/config-conventional

// commitlint.config.js
module.exports = {
  extends: ['@commitlint/config-conventional'],
  rules: {
    'type-enum': [
      2,
      'always',
      [
        'feat',     // New feature
        'fix',      // Bug fix
        'docs',     // Documentation
        'style',    // Formatting
        'refactor', // Code refactoring
        'perf',     // Performance
        'test',     // Tests
        'build',    // Build system
        'ci',       // CI configuration
        'chore',    // Maintenance
        'revert',   // Revert commit
      ],
    ],
    'scope-case': [2, 'always', 'kebab-case'],
    'subject-case': [2, 'always', 'sentence-case'],
    'header-max-length': [2, 'always', 72],
  },
}

Lefthook Integration

# lefthook.yml
commit-msg:
  commands:
    commitlint:
      run: pnpm commitlint --edit {1}

Now every commit is validated:

git commit -m "add new feature"
# ❌ Error: subject may not be empty [subject-empty]

git commit -m "feat: add dark mode"
# ✅ Success

Comparison: Changesets vs Semantic-release

Recommendation:

• Monorepo with 2+ packages: Use Changesets
• Single package, disciplined team: Use semantic-release
• Single package, less strict team: Use Changesets
• Need gradual adoption: Use Changesets

Example Workflows

Changesets: New Feature

# 1. Create feature branch
git checkout -b feat/dark-mode

# 2. Make changes
# ... edit code ...

# 3. Create changeset
pnpm changeset
# Select packages, choose "minor", add description

# 4. Commit everything
git add .
git commit -m "feat: add dark mode toggle"

# 5. Push and create PR
git push origin feat/dark-mode

# 6. After PR review and merge to main:
# - GitHub Action creates "Version Packages" PR automatically
# - Review version bumps and changelog
# - Merge "Version Packages" PR to publish

Semantic-release: Bug Fix

# 1. Create fix branch
git checkout -b fix/auth-timeout

# 2. Make changes
# ... edit code ...

# 3. Commit with conventional format
git commit -m "fix: resolve authentication timeout issue

The JWT validation was not accounting for clock skew.
Added 30-second tolerance window."

# 4. Push and create PR
git push origin fix/auth-timeout

# 5. After PR review and merge to main:
# - semantic-release automatically:
#   * Bumps version (1.0.0 → 1.0.1)
#   * Updates CHANGELOG.md
#   * Creates GitHub release
#   * Publishes to npm (if configured)

Best Practices

Do ✅

• Choose one approach: Either Changesets OR semantic-release, not both
• Enforce conventional commits: Use commitlint for consistency
• Automate with CI/CD: GitHub Actions for releases
• Write clear changeset descriptions: Future you will thank you
• Review version bumps: Check generated changelog before releasing
• Use semantic versioning: Follow MAJOR.MINOR.PATCH strictly
• Tag releases: Create git tags for every release
• Generate release notes: Automate from changeset files or commits

Don't ❌

• Don't manually edit CHANGELOG.md: Let automation handle it
• Don't skip changesets: Every PR should have a changeset (if using Changesets)
• Don't ignore breaking changes: Always document in changeset/commit
• Don't publish without CI: Automate to prevent human error
• Don't version together unnecessarily: Independent versioning where possible
• Don't forget to build: Run build before publish

Quick Setup Guide

For Changesets (Monorepo)

# 1. Install
pnpm add -D @changesets/cli
pnpm changeset init

# 2. Configure .changeset/config.json
# (see configuration section above)

# 3. Add GitHub Action
# (see workflow section above)

# 4. Add scripts to package.json
# "changeset": "changeset"
# "release": "pnpm build && pnpm changeset publish"

# 5. Document workflow in README
# How to create changesets, review process, etc.

For semantic-release (Single Package)

# 1. Install
pnpm add -D semantic-release @semantic-release/git @semantic-release/changelog

# 2. Create .releaserc.js
# (see configuration section above)

# 3. Install commitlint
pnpm add -D @commitlint/cli @commitlint/config-conventional

# 4. Configure lefthook for commit-msg hook
# (see commitlint section above)

# 5. Add GitHub Action
# (see workflow section above)

# 6. Document commit conventions in CONTRIBUTING.md

Philosophy

"Versioning should be automatic, not an afterthought."

Manual changelog maintenance leads to:

• Forgotten changes
• Incorrect version bumps
• Inconsistent release notes
• Wasted developer time

Automated changelog generation ensures:

• Every change is documented
• Versions follow semantic versioning
• Release notes are comprehensive
• Developers focus on code, not process

Choose the tool that fits your workflow, then trust the automation.

When agents design release processes, they should:

• Recommend Changesets for monorepos with multiple packages
• Recommend semantic-release for single-package repositories
• Enforce conventional commits with commitlint + Lefthook
• Automate versioning and changelog with GitHub Actions
• Follow semantic versioning (MAJOR.MINOR.PATCH) strictly
• Generate release notes from changesets or commits
• Create git tags for every release
• Document workflow clearly for team