PR Merge

Overview

This skill enables safe and comprehensive pull request merging workflows using GitHub MCP tools. It automates the complete pre-merge validation process, checks CI/CD status, verifies reviews, and executes merges with the appropriate merge strategy.

When to Use This Skill

Use this skill when the user requests:

• "Merge PR #123"
• "Can we merge this pull request?"
• "Check if PR is ready to merge"
• "Complete the PR workflow"
• "Merge this feature branch"
• "Is PR #456 ready to be merged?"

Pre-Merge Validation Workflow

Before merging any PR, execute the complete validation workflow to ensure safety and quality.

Step 1: Fetch PR Details

Use mcp__github-mcp__get_pull_request to retrieve:

• PR title and description
• Base and head branches
• Draft status
• Current state (open/closed)

Required parameters:

• owner: Repository owner
• repo: Repository name
• pullNumber: PR number

Step 2: Check CI/CD Status

Use mcp__github-mcp__get_pull_request_status to verify:

• All required checks are passing
• No failed CI/CD workflows
• Branch protection rules are satisfied

Block merge if:

• Any required checks are failing
• Checks are still pending (inform user to wait)
• Branch protection rules are not met

Step 3: Verify Reviews

Use mcp__github-mcp__get_pull_request_reviews to confirm:

• Sufficient approved reviews exist
• No requested changes are outstanding
• Review requirements are met per branch protection

Block merge if:

• Required reviews are missing
• Any reviewer has requested changes
• Review dismissals need to be addressed

Step 4: Check for Conflicts

Use mcp__github-mcp__get_pull_request_diff to identify:

• Merge conflicts with base branch
• File-level conflicts that need resolution

Block merge if:

• Merge conflicts are present (instruct user to resolve)
• Base branch needs to be updated first

Step 5: Review Changes (Optional)

For additional safety, use mcp__github-mcp__get_pull_request_files to:

• Review changed files
• Identify potential issues
• Confirm changes align with PR description

Merge Execution

Once all validations pass, execute the merge using mcp__github-mcp__merge_pull_request.

Selecting Merge Method

Choose the appropriate merge method based on project conventions and commit history:

Squash Merge (squash):

• Use for: Feature branches with messy commit history
• Benefits: Clean, single commit in main branch
• When: Multiple small commits, WIP commits, or iterative development
• Example: PR with 15 commits like "fix typo", "address review", "fix tests"

Merge Commit (merge):

• Use for: Preserving complete commit history
• Benefits: Full audit trail, maintains original commits
• When: Well-structured commits with meaningful messages
• Example: PR with clean, atomic commits following conventional commit style

Rebase Merge (rebase):

• Use for: Linear history without merge commits
• Benefits: Clean, linear git history
• When: Small PRs with few commits
• Example: Single-commit PRs or small bug fixes

Default recommendation: Use squash unless project conventions dictate otherwise.

Merge Parameters

Required:

• owner: Repository owner
• repo: Repository name
• pullNumber: PR number

Optional:

• merge_method: "merge", "squash", or "rebase" (default: merge)
• commit_title: Custom commit title for squash/merge
• commit_message: Additional commit message details

Example Merge Execution

Use mcp__github-mcp__merge_pull_request with:
- owner: "user"
- repo: "project"
- pullNumber: 123
- merge_method: "squash"
- commit_title: "feat: add user authentication system"

Post-Merge Actions

After successful merge, inform the user:

1. Confirm merge completion
2. Show resulting commit SHA
3. Note which branch was merged
4. Suggest deleting the head branch if appropriate

Do not automatically delete branches - let the user decide or check repository settings.

Safety Guidelines

Always follow these safety rules:

1. Never force merge - All checks must pass
2. Never bypass reviews - Required approvals must exist
3. Never merge with conflicts - Conflicts must be resolved first
4. Never merge draft PRs - Must be marked as ready for review
5. Always inform the user - Provide clear feedback on validation status

Validation Failure Responses

When pre-merge validation fails, provide clear, actionable feedback:

CI/CD Failures:

• List which checks are failing
• Suggest using mcp__github-mcp__get_job_logs with failed_only=true to diagnose
• Recommend reviewing workflow files

Review Issues:

• List missing required reviews
• Identify reviewers who requested changes
• Suggest addressing review comments first

Merge Conflicts:

• Identify conflicting files
• Recommend updating base branch with mcp__github-mcp__update_pull_request_branch
• Suggest resolving conflicts locally if needed

Branch Protection:

• List unmet protection rules
• Explain which requirements are blocking
• Suggest how to satisfy requirements

Advanced Features

Request Automated Review

Before merging, optionally use mcp__github-mcp__request_copilot_review to:

• Get AI-powered code review
• Identify potential issues
• Supplement human reviews

Update Branch Before Merge

If the base branch has advanced, use mcp__github-mcp__update_pull_request_branch to:

• Sync PR branch with latest base
• Trigger CI/CD re-runs
• Ensure up-to-date merge

Check Multiple PRs

For workflow automation, can validate multiple PRs in sequence:

1. Use mcp__github-mcp__list_pull_requests to find open PRs
2. Filter for PRs ready to merge
3. Execute validation workflow for each
4. Present merge candidates to user

Complete Workflow Example

User request: "Merge PR #42"

Execution sequence:

1. Fetch PR details → Confirm it's open, not draft
2. Check CI/CD status → All checks passing ✓
3. Verify reviews → 2 approvals, no requested changes ✓
4. Check conflicts → No conflicts ✓
5. Select merge method → Choose squash (clean commit history)
6. Execute merge → merge_pull_request with squash method
7. Confirm success → "PR #42 successfully merged with squash merge"

Error Handling

Handle common errors gracefully:

• 404 Not Found: PR doesn't exist, verify PR number
• 405 Method Not Allowed: PR already merged or closed
• 409 Conflict: Merge conflict exists, need resolution
• 422 Validation Failed: Branch protection rules not met

Provide clear error messages and next steps for resolution.

Resources

This skill uses GitHub MCP tools exclusively and does not require additional scripts, references, or assets. All functionality is provided through the MCP integration.