The Merge Action allows you to automatically merge pull requests when they pass all validations. This is useful for automating routine merges, reducing manual work, and maintaining a consistent workflow.

​
Configuration

​
method
string
default:"merge"
Merge method to use: “merge”, “squash”, or “rebase”
​
commit_title
string
Custom title for the merge commit (supports templates)
​
commit_message
string
Custom message for the merge commit (supports templates)

​
Basic Usage

on_success:
  - merge:
      method: "squash"

​
Examples

​
Simple Auto-Merge

Automatically merge PRs that pass all validations: 
on_success:
  - merge:
      method: "merge"

​
Custom Commit Messages

Specify custom titles and messages for merge commits: 
on_success:
  - merge:
      method: "squash"
      commit_title: "{{ pull_request.title }} (#{{ pull_request.number }})"
      commit_message: |
        {{ pull_request.body }}
        
        Merged by Rulesets automation.

​
Conditional Auto-Merge

Merge documentation PRs automatically after review: 
ruleset:
  - name: "Auto-merge Documentation Updates"
    when:
      - "pull_request_review.submitted"
    if:
      - type: "files"
        modified:
          match: "^(docs/|README.md|*.md)$"
      - type: "label"
        match: "documentation"
    validate:
      - type: "approvals"
        count:
          min: 1
    on_success:
      - merge:
          method: "squash"
          commit_title: "docs: {{ pull_request.title }}"

​
Merge Methods

Creates a merge commit that preserves all commit history from the PR branch.
merge:
  method: "merge"
Best for: Preserving detailed history and context of changes.

​
How It Works

1

Check Mergeability

The action first checks if the PR is mergeable
2

Process Templates

If custom commit titles or messages are provided, it processes the templates
3

Perform Merge

The action merges the PR using the specified method

​
Error Handling

The Merge Action will fail under these conditions:
  • PR has merge conflicts
  • PR doesn’t meet branch protection requirements
  • Required status checks are failing
  • User lacks permission to merge
When merge fails, the error will be logged but won’t affect other actions.

​
Use Cases

​
Auto-Merge Dependency Updates

Automatically merge dependency updates that pass tests: 
ruleset:
  - name: "Auto-merge Dependencies"
    when:
      - "pull_request.opened"
      - "pull_request.synchronize"
      - "check_suite.completed"
    if:
      - type: "author"
        match: ["dependabot", "renovate"]
      - type: "check_suite"
        status: "success"
    validate:
      - type: "size"
        files: 5
        ignore: ["package-lock.json", "yarn.lock"]
    on_success:
      - merge:
          method: "squash"
          commit_title: "chore(deps): {{ pull_request.title }}"

​
Auto-Merge Typo Fixes

Automatically merge simple typo fixes after approval: 
ruleset:
  - name: "Auto-merge Typo Fixes"
    when:
      - "pull_request_review.submitted"
    if:
      - type: "title"
        match: "^fix\\(typo\\): .*"
      - type: "size"
        total: 50
    validate:
      - type: "approvals"
        count:
          min: 1
    on_success:
      - merge:
          method: "squash"

​
Auto-Merge for Specific Labels

Merge PRs with specific labels after CI success: 
ruleset:
  - name: "Auto-merge Labeled PRs"
    when:
      - "check_suite.completed"
      - "pull_request.labeled"
    if:
      - type: "label"
        match: "auto-merge"
      - type: "check_suite"
        status: "success"
    validate:
      - type: "approvals"
        count:
          min: 2
    on_success:
      - merge:
          method: "merge"

​
Best Practices

Use with appropriate validation checks to ensure quality
Consider branch protection rules when setting up auto-merge
Choose the merge method that best fits your workflow
Use custom commit messages to maintain a meaningful history
Be cautious with auto-merge on critical branches - always include sufficient validation

​
Security Considerations

  • Only enable auto-merge for trusted contributors or with strict validation
  • Ensure all required checks (tests, approvals) are passing before merge
  • Consider limiting auto-merge to non-critical repositories or branches
  • Maintain audit logs of auto-merged PRs