contributing

name	contributing
description	Guides the contribution workflow for Apache Beam, including creating PRs, issue management, code review process, and release cycles. Use when contributing code, creating PRs, or understanding the contribution process.

Contributing to Apache Beam

Getting Started

Prerequisites

• GitHub account
• Java JDK 11 (preferred, or 8, 17, 21)
• Latest Go 1.x
• Docker
• Python (any supported version for manual testing, all versions for running test suites)
• For large contributions: signed ICLA to Apache Software Foundation

Environment Setup Options

Local Setup (automated)

./local-env-setup.sh

Docker-based Setup

./start-build-env.sh

Contribution Workflow

1. Find or Create an Issue

• Search existing issues at https://github.com/apache/beam/issues
• Create new issue using appropriate template

2. Claim the Issue

.take-issue    # Assigns issue to you
.free-issue    # Unassigns issue from you
.close-issue   # Closes the issue

3. For Large Changes

• Discuss on [e-mail] mailing list
• Create design doc using template
• Review existing design docs

4. Make Your Changes

• Every source file needs Apache license header
• New dependencies must have Apache-compatible open source licenses
• Add unit tests for your changes
• Use descriptive commit messages

5. Create Pull Request

• Link to the issue in PR description
• Pre-commit tests run automatically
• If tests fail unrelated to your change, comment: retest this please

6. Code Review

• Reviewers are auto-assigned within a few hours
• Use R: @username to request specific reviewer
• No response in 3 days? Email [e-mail]

Code Review Best Practices

For Authors

• Provide context in issue and PR description
• Avoid huge mega-changes
• Add follow-up changes as "fixup" commits (don't squash until approved)
• Squash fixup commits after approval

For Reviewers

• PRs can only be merged by Beam committers

Testing Workflows

Pre-commit Tests

Run automatically on PRs. To run locally:

./gradlew javaPreCommit      # Java
./gradlew :sdks:python:test  # Python
./gradlew :sdks:go:test      # Go

Post-commit Tests

Run after merge. Trigger phrases in PR comments start specific test suites. See trigger phrase catalog.

Formatting

Java

./gradlew spotlessApply

Python

# Uses yapf, isort, pylint
pre-commit run --all-files

CHANGES.md

./gradlew formatChanges

Release Cycle

• Minor releases every 6 weeks
• Check release calendar
• Changes must be in master before release branch is cut

Stale PRs

• PRs become stale after 60 days of author inactivity
• Community will close stale PRs
• Authors can reopen closed PRs

Key Resources

• Contribution Guide
• PTransform Style Guide
• Runner Authoring Guide
• Wiki Tips
  • Git Tips
  • Java Tips
  • Python Tips
  • Go Tips
  • Gradle Tips

Communication

• User mailing list: [e-mail]
• Dev mailing list: [e-mail]
• Slack: #beam channel
• Issues: https://github.com/apache/beam/issues