pr-guardian（公关卫士）

PR Guardian

Watch a PR, detect problems, fix them, repeat — until everything is green.

Why this exists

After pushing a PR you typically wait for CI, check for merge conflicts, and respond to CodeRabbit review comments. Each issue requires a separate manual step. PR Guardian automates the entire feedback loop: it uses gh run watch to efficiently wait for CI completion (consuming zero session cycles while waiting), then polls the PR status, dispatches the appropriate fix skill when a problem is found, and exits only when all checks pass (or the iteration limit is reached).

Quick start

/pr-guardian                     # Default: 5 min interval, 20 max iterations
/pr-guardian --interval 3        # Poll every 3 minutes
/pr-guardian --max-iterations 10 # Give up after 10 cycles

Workflow

Step 0: Validate preconditions

Before starting the loop, verify:

1. gh CLI is installed and authenticated
2. Current branch has an open PR (gh pr view)
3. Display the PR number and URL

If any check fails, report the error and stop.

Step 1: Wait for CI with gh run watch

Before polling, wait for all GitHub Actions workflow runs to complete using gh run watch. This blocks at the shell level until CI finishes, consuming zero Claude Code session cycles while waiting.

# Get the latest workflow run for the current branch
RUN_ID=$(gh run list --branch "$(git rev-parse --abbrev-ref HEAD)" \
  --limit 1 --json databaseId --jq '.[0].databaseId' 2>/dev/null || echo "")

if [[ -n "$RUN_ID" ]]; then
  # Block until this run completes (exit code reflects pass/fail)
  gh run watch "$RUN_ID" --exit-status 2>/dev/null || true
fi

Fallback: If gh run watch is unavailable or fails (e.g., no workflow runs found yet on the first cycle after push), skip straight to Step 2 and let the polling script detect checks_running > 0.

Step 2: Poll PR status

Run the bundled status script:

bash <skill-path>/scripts/poll_pr_status.sh

This returns a JSON object with these fields:

Important: all_green is only true when ALL of these hold:

• No merge conflicts
• No CI failures
• No CI checks still running
• CodeRabbit check is NOT pending AND NOT none (review must have completed at least once)
• No unresolved CodeRabbit inline comments (comments marked ✅ Addressed are excluded)
• At least one CI check exists

Step 3: Evaluate and report

Print a concise status line each cycle:

[PR Guardian] Cycle 3/20 — PR #42
  CI: 4 passed, 1 failed, 0 running
  Conflicts: none
  CodeRabbit: review completed, 2 inline comments
  → Action: fixing CodeRabbit comments

Step 4: Dispatch fixes (priority order)

When issues are found, fix them one category at a time in this order. Only fix one category per cycle — after fixing, go back to Step 1 to re-poll, because a fix may have changed the state (e.g., a push triggers new CI runs and gh run watch will wait for them).

Priority 1 — Merge conflicts

Merge conflicts block everything else. When has_conflict is true:

1. Invoke /fix-conflict
2. After resolution, the push triggers new CI runs — go back to Step 1

Priority 2 — CI failures

When checks_failed > 0 and checks_running == 0 (Step 1's gh run watch already waited, so running should normally be 0):

1. Invoke /fix-ci
2. After the fix commit is pushed, go back to Step 1

Priority 3 — CodeRabbit review comments

When coderabbit_check == "pass" and coderabbit_comments > 0 and CI is passing:

1. Invoke /fix-review
2. /fix-review will verify each finding against current code before fixing
3. After the fix commit is pushed, go back to Step 1

IMPORTANT: Only dispatch /fix-review when coderabbit_check is "pass" (review completed). If it is "pending", wait — the review is still in progress and comments may not be final yet.

Step 5: Handle pending states

The correct action is to wait (not fix) when:

• checks_running > 0: CI is still running — this should be rare since Step 1 already waited via gh run watch, but can happen if new runs were triggered between watch and poll
• coderabbit_check == "pending": CodeRabbit review is in progress — wait with a short sleep (60-120 seconds) and re-run Step 2 only. Do NOT go back to Step 1 (gh run watch) — CodeRabbit is not a GitHub Actions run. Retry up to 5 times before moving to the next full cycle
• coderabbit_check == "none": CodeRabbit hasn't started yet (common right after a push) — same short-sleep retry as pending
• checks_total == 0 and it's the first cycle: checks haven't started yet — go back to Step 1 where gh run watch will block until they appear

Do not invoke any fix skill while checks are still running or reviews are pending — you would be fixing based on incomplete information.

Step 6: Check exit conditions

After each cycle, check:

1. All green (all_green == true): Print success message and exit
2. Max iterations reached: Print summary of remaining issues and exit
3. Same failure repeated 3 times: The automatic fix is not working. Print what failed and suggest manual intervention, then exit

If none of these conditions are met, go back to Step 1. There is no fixed sleep between cycles — gh run watch in Step 1 provides the natural wait for CI to complete after a fix push.

Configuration

Exit messages

Success:

[PR Guardian] All checks green! PR #42 is ready.
  CI: 6/6 passed | Conflicts: none | CodeRabbit: pass, 0 comments
  Completed in 3 cycles over 15 minutes.

Max iterations:

[PR Guardian] Reached 20 cycles without all-green.
  Remaining issues:
    - CI: tests failing (pytest assertion error in test_auth.py)
    - CodeRabbit: 2 unresolved inline comments
  Manual intervention needed.

Repeated failure:

[PR Guardian] Same CI failure persisted after 3 fix attempts.
  Failing check: tests
  Last error: AssertionError in test_auth.py:42
  Automatic repair is not resolving this — please fix manually.

Important notes

• This skill composes /fix-conflict, /fix-ci, and /fix-review. It does not reimplement their logic — it orchestrates them.
• Only one fix category is attempted per cycle to avoid cascading changes that confuse the state.
• gh run watch replaces the old fixed-interval sleep loop for CI waiting. This eliminates wasted polling cycles and reduces session consumption from 5-10 cycles to 1-3 for a typical PR.
• The skill respects both CI timing AND CodeRabbit timing: gh run watch handles CI, and a short-sleep retry loop (60-120s, max 5 retries) handles CodeRabbit pending states.
• Synapse-independent: This skill depends only on gh CLI and standard git commands. It works outside Synapse environments.
• If gh run watch is unavailable (no runs found, older gh version), the skill falls back to the polling script detecting checks_running > 0 and retrying on the next cycle.
• CodeRabbit check status (pending/pass/fail) is tracked separately from inline comment count. A pending check means the review is still running — do NOT dispatch /fix-review yet.
• Each fix skill handles its own commit and push. PR Guardian only handles the loop and dispatch.
• /fix-review verifies each CodeRabbit finding against the current code before applying fixes — it does not blindly apply suggestions.