# Review by Staff Security Engineer (Round 2)

## Staff Security Engineer — Review Complete

**374 tests pass.** All 7 functional requirements implemented across 5 commits (+373 / -1 lines).

### Security Assessment

**No security concerns.** This is a minimal, well-isolated change:

- **No new OAuth scopes** — `reactions:write` already covers `reactions.remove`
- **No user-controlled input** — all emoji names are hardcoded string literals (`"eyes"`, `"white_check_mark"`, `"x"`, `"tada"`). Zero injection risk.
- **Proper failure isolation** — each Slack API call is in its own independent try/except. The critical completion signal is never gated on cosmetic cleanup.
- **No secrets in diff** — verified clean
- **`remove_reaction()` does not swallow exceptions** — correctly delegates error policy to callers, verified by `test_propagates_exception`
- **No new dependencies** — zero new imports or packages
- **Audit trail** — all failures logged at debug level with `exc_info=True`, each with a distinct message

VERDICT: **approve**

FINDINGS:
- [src/colonyos/slack.py]: `remove_reaction()` correctly does not swallow exceptions, delegating error policy to callers. No new attack surface.
- [src/colonyos/cli.py]: Both completion paths use hardcoded emoji literals — no user-controlled input reaches `reactions_remove`. Each API call is independently wrapped in try/except.
- [tests/test_cli.py]: Tests replicate the exact call sequence from `cli.py` rather than testing the actual code path through QueueExecutor. Acceptable trade-off.
- [tests/test_slack.py]: `test_propagates_exception` verifies the helper doesn't swallow errors. Protocol test correctly updated.

SYNTHESIS:
This is a clean, minimal change with zero security concerns. 19 lines of production code, one new API wrapper, two identical completion blocks, all with proper failure isolation. No new scopes, no user input in API calls, no secrets, no new dependencies. Ship it.

Review artifact saved to `cOS_reviews/reviews/staff_security_engineer/20260331_220500_round1_when_you_finish_working_on_a_feature_requested_f_b962cb06df.md`.
