# Review by Andrej Karpathy (Round 2)

## Review Complete — Andrej Karpathy

**VERDICT: approve** ✅

### Key findings:

1. **Chokepoint design is exactly right**: The entire feature hangs on two surgical changes — `critical` kwarg on `_post_slack_message` and a daily-thread branch in `_ensure_notification_thread`. No shotgun refactor needed.

2. **Zero LLM cost, as promised**: `format_daily_summary` is pure, deterministic, and testable. No stochastic outputs. This is the correct V1 — you can layer LLM summarization on top later.

3. **Hour-aware rotation is now correct**: The `_should_rotate_daily_thread` three-branch logic (None → rotate, same date → skip, stale date → check hour) was broken in earlier iterations and is now fixed with proper tests.

4. **`_post_slack_message` refactor is a net win**: Eliminates duplicated inline token lookup, consolidates through `_get_notification_client()`.

5. **All 52 new tests pass**, covering lifecycle, routing, summary generation, integration, and restart recovery. The integration test correctly asserts the "1 top-level message, N threaded replies" invariant.

**Minor non-blocking notes**: Summary filters by `added_at` date (not completion date), and user-controlled fields flow into Slack mrkdwn unsanitized — but both are pre-existing patterns, not regressions.

Review artifact written to `cOS_reviews/reviews/andrej_karpathy/20260401_round1_you_are_sending_too_many_slack_messages_to_the_m_1b324759d9.md`.