# Performance Review Report

**Branch**: feat/177-agent-adapter-migration -> main
**Date**: 2026-05-19

## Issues in Your Changes (BLOCKING)

### CRITICAL

(none)

### HIGH

(none)

## Issues in Code You Touched (Should Fix)

(none)

## Pre-existing Issues (Not Blocking)

(none)

## Suggestions (Lower Confidence)

(none -- all changes are performance-neutral or mildly beneficial)

## Summary

| Category | CRITICAL | HIGH | MEDIUM | LOW |
|----------|----------|------|--------|-----|
| Blocking | 0 | 0 | 0 | 0 |
| Should Fix | 0 | 0 | 0 | 0 |
| Pre-existing | 0 | 0 | 0 | 0 |

**Performance Score**: 9/10
**Recommendation**: APPROVED

## Analysis Notes

This PR's runtime code changes are small and well-scoped from a performance perspective:

1. **buildTmuxCommand taskId guard** (`base-agent-adapter.ts:125-132`): The new early-return guard prevents the expensive `resolveSpawnConfig()` call (which does synchronous file I/O via `loadConfigFile()` -> `readFileSync`) when `taskId` is missing. This is a minor performance improvement -- fail-fast before disk I/O.

2. **Explicit type narrowing** (`base-agent-adapter.ts:141`): Replaces an `as TmuxAgentType` cast with a ternary expression. Zero runtime cost difference.

3. **Migration v28 -- UPDATE tasks** (`database.ts:1077`): `UPDATE tasks SET agent = NULL WHERE agent = 'gemini'` performs a full table scan since `tasks.agent` has no index. This is acceptable: migrations run once at startup, and the `loops` table recreation (already present in the prior version of v28) follows the same established pattern used in migrations v2, v3, v11, v22, and v26. The tasks UPDATE adds negligible cost on top of the loops table copy.

4. **No new hot-path allocations**: No new per-request object creation, no new loops, no new I/O calls in the request path. The `resolveSpawnConfig()` call inside `buildTmuxCommand` was already present before this PR.

5. **Pre-existing patterns reviewed and confirmed acceptable**: The synchronous `loadConfigFile()` call in `resolveSpawnConfig()` (using `readFileSync`) and the `process.env` iteration in `buildSpawnEnv()` are pre-existing patterns used by all spawn paths (spawn, spawnInteractive, buildTmuxCommand). These are not introduced by this PR and run at process-spawn frequency (not hot-path).

The score is 9/10 rather than 10/10 only because the pre-existing `loadConfigFile()` sync I/O pattern in the spawn path is not ideal for high-throughput scenarios, but that is outside the scope of this PR and runs at task-spawn frequency (seconds apart at minimum).
