/phx:watch-pr

/phx:watch-pr <PR number or URL> [--checks-only] [--fix]

Watch PR (Token-Conscious)

Watch a PR’s reviews, comments, and CI with a background watcher that wakes Claude ONLY on real events — no foreground sleep loops, no context bloat. The watcher polls quietly in its own process; nothing enters context until something genuinely changed.

Usage

/phx:watch-pr 42                 # watch reviews + comments + checks
/phx:watch-pr 42 --checks-only   # CI only (delegates to gh pr checks --watch)
/phx:watch-pr 42 --fix           # on actionable review, draft fixes too

Iron Laws

1. NEVER foreground-poll with sleep in the session — use the background watcher (Monitor / run_in_background). Foreground polling bloats context and straddles the 5-min cache TTL
2. Deltas ONLY enter context — never dump full gh JSON. The watcher emits one-line events; read .claude/watch/pr-{n}.jsonl on demand
3. Silence is not success — the watcher MUST emit on PR closed/merged, CI failure, repeated gh errors, and watchdog timeout — not just “new comment”. A silent watcher looks identical to a hung one
4. NEVER auto-post replies or auto-push — hand off to /phx:pr-review for responses; show drafts and get approval
5. Bound every watch — default MAX_DURATION 3600s; always stop on terminal state

Workflow

Step 1: Parse Arguments

Extract PR number (from number or URL — URL also yields the repo). Detect --checks-only / --fix. Baseline timestamp = now; events are “new since baseline”, so old reviews don’t re-fire.

Step 2a: --checks-only Path

No custom poller needed — gh pr checks --watch blocks until all checks finish, then exits. Run via Bash with run_in_background: true:

gh pr checks {n} --watch --fail-fast --interval 10

Exit code is the signal: 0 = pass, 1 = fail, 8 = pending. On exit, report the conclusion; on failure, offer /phx:investigate with the failing job log (gh run view {run-id} --log-failed).

Step 2b: Full Watch Path

Start the Monitor tool (preferred — streams each event line back) on:

${CLAUDE_SKILL_DIR}/scripts/watch-pr.sh {n} reviews,comments,checks

with timeout_ms = MAX_DURATION × 1000. Where Monitor is unavailable (Bedrock/Vertex/Foundry), run the same script via Bash run_in_background: true — it exits on the first terminal event instead. Stay idle or keep working until an event lands.

Step 3: React Per Event

Event	Action
review / comment (actionable)	Summarize the delta; with --fix draft fixes + mix compile && mix test; route reply drafting to /phx:pr-review {n}
check conclusion failure	Offer /phx:investigate on the failing job
merged / pr_closed / watchdog / watch_error	Stop, report final state

Step 4: Stop

The watcher self-terminates on terminal states. To stop early: TaskStop the background task or cancel the monitor.

Integration

push / open PR → /phx:watch-pr {n} ──(new review)──► /phx:pr-review {n}
                              ├──────(CI fail)─────► /phx:investigate
                              └──────(merged)──────► done

References

• ${CLAUDE_SKILL_DIR}/references/watcher-mechanics.md — cache TTL math, Monitor vs run_in_background vs ScheduleWakeup, rate-limit notes