# Review by Principal Systems Engineer (Google/Stripe caliber) (Round 1)

I now have a complete picture of the implementation. Let me write the review.

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## Review: `colonyos show <run-id>` — Principal Systems Engineer Perspective

### Completeness Assessment

**All PRD functional requirements are implemented:**

| Requirement | Status | Notes |
|---|---|---|
| FR-1: Run Resolution by ID Prefix | ✅ | Prefix, substring, exact match, path traversal validation, zero/ambiguous/unique cases |
| FR-2: Run Header Panel | ✅ | Status coloring, wall-clock duration, prompt truncation (120 chars), source_issue_url, last_successful_phase |
| FR-3: Phase Timeline Table | ✅ | Collapsed review groups (`review x3`), round numbering, fix-round boundaries, `is_skipped` dim styling |
| FR-4: Review Details Section | ✅ | Conditional, computed from phase list |
| FR-5: Decision Gate Section | ✅ | Conditional |
| FR-6: CI Section | ✅ | Conditional, attempt count, final status |
| FR-7: Artifact Links | ✅ | PRD, task file, branch, issue URL |
| FR-8: `--json` Flag | ✅ | Raw run_data `json.dumps` with `indent=2` to stdout |
| FR-9: `--phase` Filter | ✅ | Session ID, model, error, per-execution detail |

**All 51 tasks marked complete.** All 865 tests pass with zero regressions.

### Findings

**Minor Issues:**

1. **[src/colonyos/cli.py]**: Unused `import subprocess` added at the top of the file — this import belongs to the ci-fix feature from a prior commit on this branch, not the show command. The show commit itself is clean, but the branch carries this forward.

2. **[src/colonyos/show.py:149]**: `load_single_run` constructs a file path from `run_id` without re-validating it. This is safe in the current call chain (CLI always calls `resolve_run_id` first, which validates), but the function's public API doesn't enforce this invariant. If someone calls `load_single_run(runs_dir, "../etc/passwd")` directly, `Path` joining could traverse. **Low risk** since `resolve_run_id` already gates input, but a defensive `validate_run_id_input(run_id)` call in `load_single_run` would close the gap.

3. **[src/colonyos/show.py:109]**: `resolve_run_id` returns `str | list[str]` — a tagged union without an actual tag. The caller in `cli.py` uses `isinstance(resolved, list)` to discriminate. This works but is fragile; a `dataclass` result type (e.g., `ResolvedRun` / `AmbiguousMatch`) would be more type-safe. **Cosmetic** — the current approach matches Python idioms for simple CLIs.

4. **[src/colonyos/show.py:129]**: Substring matching (`partial_id in run_id`) is intentionally broad per the PRD, but a very short partial ID (1-2 chars like "r" or "20") would match every run file. There's no minimum prefix length enforced. The PRD's success metric mentions "4+ character prefixes" — the code doesn't enforce this but that's fine since the ambiguity exit handles it gracefully.

5. **[src/colonyos/cli.py]**: The `--json` path outputs the raw `run_data` dict (the full JSON file contents), not the structured `ShowResult`. This means `--json` output includes the full prompt (not truncated) which is correct per the PRD, and the schema matches the persisted file format. But it also means `--json` output won't include computed fields like `wall_clock_ms`, `review_rounds`, collapsed timeline entries, etc. This is a design trade-off — the PRD says "output the run data as formatted JSON" which supports this interpretation, but a user piping `--json | jq '.phases'` gets raw phases, not the collapsed view.

6. **[branch]**: The branch carries 4 prior commits from the `ci-fix` feature (468 LOC in `src/colonyos/ci.py`, 369 LOC in `tests/test_ci.py`, etc.) that are unrelated to the show command. The show-specific commit (`9062186`) is clean and isolated. This is a merge hygiene issue, not a code quality issue.

### Quality Assessment

**Strengths:**
- Clean data-layer / render-layer separation exactly matching the `stats.py` pattern
- 51 dedicated unit tests with strong coverage of edge cases (empty phases, collapsed groups, round boundaries, path traversal)
- 7 CLI integration tests covering all user-facing paths (full ID, prefix, bad ID, ambiguous, JSON, phase filter)
- Pure functions for all compute logic — trivially testable, no side effects
- Path traversal protection with explicit regex validation
- Error messages go to stderr, exit codes are non-zero on failure
- Review phase collapsing handles the 19-phase run case correctly

**No issues found with:**
- No secrets or credentials
- No destructive operations
- No unnecessary dependencies (uses only existing `rich`, `click`, `json`, `pathlib`)
- No TODO/placeholder code
- No linter issues in new code

VERDICT: approve

FINDINGS:
- [src/colonyos/cli.py]: Unused `import subprocess` carried from prior ci-fix commits on this branch (not from the show commit itself)
- [src/colonyos/show.py:149]: `load_single_run` doesn't re-validate run_id for path traversal — safe in current flow but the public function lacks defense-in-depth
- [src/colonyos/show.py:109]: `str | list[str]` return type is a stringly-typed union; a proper result type would be more robust but is acceptable for this scope
- [src/colonyos/cli.py]: `--json` outputs raw persisted data, not the computed ShowResult — means computed fields (wall_clock_ms, collapsed timeline) are absent from JSON output
- [branch]: Branch includes 4 unrelated ci-fix commits adding ~1300 LOC not part of this feature

SYNTHESIS:
This is a well-executed feature that follows the established architectural patterns precisely. The data/render separation makes every compute function independently testable, and the test suite is thorough — 51 unit tests plus 7 CLI integration tests cover the happy paths, error paths, and edge cases (path traversal, ambiguous prefixes, collapsed review groups). The code is production-ready from a reliability perspective: errors surface clearly to stderr with non-zero exits, the path traversal guard is sound, and the rendering gracefully handles missing/empty sections. The two substantive findings — the lack of defense-in-depth in `load_single_run` and the raw-data `--json` output — are both reasonable design decisions for v1 and can be tightened in follow-ups. The branch hygiene issue (unrelated ci-fix commits) is a merge workflow concern, not a code quality issue. From a "3am debugging" perspective, this command gives you exactly what you need: run status, phase-by-phase cost/duration breakdown, and artifact paths — all in under 200ms.