The PR Agent is a unified 5-phase workflow for investigating GitHub issues and reviewing/working on pull requests. It handles everything from context gathering through test verification, fix exploration, and creating PRs or review reports.

For the best results, start in plan mode to create and review a detailed plan before execution:

1. Enter plan mode: Press Shift+Tab or use /plan
2. Request a review plan:

   /plan review PR #12345 - create a detailed plan for the review
   

3. Review the plan: Copilot will create a structured plan. Review the steps and make adjustments.
4. Exit plan mode: Press Shift+Tab to switch back to execution mode
5. Execute the plan:

   proceed with the plan
   

This workflow gives you control over the review approach before any actions are taken.

If you prefer to start immediately without planning:

# Start GitHub Copilot CLI
copilot

# Invoke the PR agent
/agent pr

# Then ask it to work on an issue or PR
please fix issue #12345
please review PR #67890

┌─────────────────────────────────────────┐     ┌─────────────────────────────────────────────┐
│  Phases 1-3 (pr.md)                     │     │  Phases 4-5 (post-gate.md)                  │
│                                         │     │                                             │
│  1. Pre-Flight  →  2. Tests  →  3. Gate │ ──► │  4. Fix  →  5. Report                       │
│                          ⛔              │     │                                             │
│                     MUST PASS            │     │  (Only after Gate ✅ PASSED)                │
└─────────────────────────────────────────┘     └─────────────────────────────────────────────┘

Typical time: ~2-5 minutes

Context gathering only - no code analysis, no fix opinions, no running tests.

• Create state file in CustomAgentLogsTmp/PRState/pr-XXXXX.md
• Read issue description and comments
• Document platforms affected
• Identify files changed (if PR exists)
• Note disagreements and edge cases from comments

Typical time: ~5-15 minutes (longer if creating new tests)

Ensure reproduction tests exist - tests must be verified to FAIL.

• Check if tests already exist in PR
• If not, create them using the write-ui-tests or write-xaml-tests skill
• Verify tests compile
• Verify tests FAIL (reproduce the bug)

Typical time: ~5-10 minutes

Mandatory checkpoint - must pass before continuing.

• For PRs: Verify tests FAIL without fix, PASS with fix
• For Issues: Confirm tests were verified to fail in Phase 2
• Uses verify-tests-fail-without-fix skill

If Gate fails, stop and fix the tests before proceeding.

Typical time: ~10-30 minutes (varies by complexity)

Explore independent alternatives using the try-fix skill.

Even when a PR already has a fix, Phase 4 requires running try-fix to:

1. Generate independent fix ideas (without looking at PR's solution)
2. Test alternatives empirically
3. Compare with PR's fix

The PR's fix is already validated by Gate. The try-fix skill explores if there's something better.

Typical time: ~2-5 minutes

Deliver the result:

• For PRs: Write review with APPROVE or REQUEST CHANGES
• For Issues: Create a new PR with the fix

The agent maintains state in CustomAgentLogsTmp/PRState/pr-XXXXX.md files. This allows:

• Resuming interrupted sessions
• Tracking progress across phases
• Recording fix attempts and their outcomes

• UI Testing Guide - How to write UI tests
• XAML Testing Guide - How to write XAML unit tests
• Contributing Guidelines