Release builder

This repository contains a collection of GitHub composite actions used for rolling releases in our projects.

The release builder automatically generates changelogs from merged pull requests since your last release tag. PR titles are collected and formatted into release notes - no manual changelog maintenance required.

🎯 Controlling Release Versions

Any PR merged between release tags can control the next release version by including keywords in the PR title.

How It Works

The release builder scans all merged PRs between the last release tag and HEAD. If any PR title contains version keywords, the next release will use that version type:

• [minor], (minor), or #minor → Next release will be a minor version bump (e.g., 1.2.3 → 1.3.0)
• [major], (major), or #major → Next release will be a major version bump (e.g., 1.2.3 → 2.0.0)
• No keywords → Defaults to patch version bump (e.g., 1.2.3 → 1.2.4)

Examples

To force a minor release, include [minor] in your PR title:

• ✅ Add new authentication feature [minor]
• ✅ Implement user dashboard (minor)
• ✅ Update API endpoints #minor

Important:

• Keywords are case-insensitive
• [major] takes precedence over [minor] if both appear
• Only one PR with [minor] is needed to trigger a minor release for all PRs in that batch
• The keyword can appear anywhere in the PR title

Example Scenario

If you merge these PRs between releases:

1. "Fix bug in login" (no keyword → patch)
2. "Add new feature [minor]" (has keyword → minor)
3. "Fix another bug" (no keyword, but still minor due to #2)

The next release will be a minor version bump because at least one PR contained [minor].

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Prerequisites

Required Setup

1. Version file (if using package-version action) - Your repository needs one of: package.json/package-lock.json (npm), pyproject.toml (Python), or a plain VERSION file.

That's it. Both CHANGELOG.md and an initial release tag are optional:

• No CHANGELOG.md? The pull-request action creates one automatically, noting the tag from which the changelog was introduced.
• No previous tag? The version defaults to 0.0.0, so your first release will be 0.0.1 (or 0.1.0/1.0.0 based on PR titles).

If you want to start from a specific version, create an initial tag:

git tag v1.0.0
git push origin v1.0.0

Secrets

Secret	Required For	Description
GITHUB_TOKEN	All actions	Automatically provided by GitHub Actions
SLACK_BOT_TOKEN	slack-message	Slack bot token for posting notifications
SLACK_CHANNEL	slack-message	Slack channel ID for notifications

Repository Variables (Optional)

Variable	Description
RELEASE_BUILDER_PENDING_ICON	Icon URL for pending release status
RELEASE_BUILDER_FAILURE_ICON	Icon URL for failed release status

Actions

build-changelog

Builds a changelog from PRs merged since the last release tag. The action automatically:

• Finds all merged PRs between the previous tag and HEAD
• Generates formatted release notes from PR titles
• Determines the next semantic version based on PR title conventions

No existing changelog content is required - notes are generated entirely from your merged PRs.

Outputs:

Output	Description
has-prs	Whether any PRs were found since the last release
previous-version	The previous release tag
next-version	The calculated next version
notes	The generated changelog notes
release	The release type (major, minor, or patch)

Semantic Versioning:

The release type is determined by scanning PR titles for keywords:

• [major], (major), or #major - triggers a major version bump
• [minor], (minor), or #minor - triggers a minor version bump
• Otherwise defaults to patch

How version detection works:

• All merged PRs between the last release tag and HEAD are scanned
• If any PR title contains [minor], (minor), or #minor, the entire release batch becomes a minor version bump
• If any PR title contains [major], (major), or #major, the entire release batch becomes a major version bump (takes precedence over minor)
• Keywords are case-insensitive and can appear anywhere in the PR title
• If no keywords are found, defaults to patch version bump

Usage:

- uses: actions/checkout@v4
  with:
    fetch-depth: 0

- id: changelog
  uses: flowcanon/release-builder/build-changelog@v2

Note: fetch-depth: 0 is required so the action can access full git history for tag resolution.

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package-version

Updates the version field in your project's package file. Automatically detects the project type:

• npm: Updates package.json and package-lock.json
• Python: Updates pyproject.toml
• VERSION file: Writes the version to a plain VERSION file

Inputs:

Input	Required	Description
version	Yes	The version string to set

Usage:

- uses: flowcanon/release-builder/package-version@v2
  with:
    version: ${{ needs.build_changelog.outputs.next-version }}

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pull-request

Creates a release pull request with an updated CHANGELOG.md file.

Inputs:

Input	Required	Description
next-version	Yes	The version being released
notes	Yes	The changelog notes for this release
previous-version	Yes	The previous version tag
release	Yes	The release type (major, minor, or patch)

Usage:

- uses: flowcanon/release-builder/pull-request@v2
  with:
    next-version: ${{ needs.build_changelog.outputs.next-version }}
    notes: ${{ needs.build_changelog.outputs.notes }}
    previous-version: ${{ needs.build_changelog.outputs.previous-version }}
    release: ${{ needs.build_changelog.outputs.release }}

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slack-message

Sends Slack notifications about release status. Can send an initial "pending" message and update it with the final status.

Inputs:

Input	Required	Default	Description
channel-id	Yes	-	The Slack channel ID to post to
message-id	No	-	Message timestamp to update (for status updates)
status	No	pending	Status of the release (pending, success, failure)

Outputs:

Output	Description
channel-id	The channel ID (pass-through)
message-id	The message timestamp (for subsequent updates)

Required Environment Variables:

Variable	Description
GITHUB_TOKEN	GitHub token for API access
PROJECT_NAME	Name of the project being released
SLACK_BOT_TOKEN	Slack bot token for posting messages
TARGET_NAME	Display name of the deployment target
TARGET_URL	URL of the deployment target
RELEASE_PENDING_ICON	(Optional) Icon URL for pending status
RELEASE_FAILURE_ICON	(Optional) Icon URL for failure status

Usage:

# Send initial pending message
- id: message
  uses: flowcanon/release-builder/slack-message@v2
  with:
    channel-id: ${{ env.SLACK_CHANNEL }}

# Update with final status
- if: always()
  uses: flowcanon/release-builder/slack-message@v2
  with:
    channel-id: ${{ steps.message.outputs.channel-id }}
    message-id: ${{ steps.message.outputs.message-id }}
    status: ${{ steps.deploy.conclusion }}

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Example

This repository uses its own actions for releases. See .github/workflows/release.yml for a working implementation.

License

See LICENSE.md.