regression-watch

# Regression Watch Detect whether Claude Code sessions are getting worse over time across quality and efficiency metrics, using Agent Monitor data. ## Input The user provides: **$ARGUMENTS** This may be: - empty or "all" — check every regression metric (default) - "errors" — error-rate regression only - "cache" — cache hit-rate regression only - "compaction" — compaction-frequency regression only - "cost" — cost-per-session regression only - A window like "last 30d" or "30 vs 90" — set the recent vs baseline window sizes ## Data Sources | Endpoint | Returns | |----------|---------| | `GET /api/analytics` | `daily_events` (365d), `daily_sessions` (365d), `event_types`, `tokens` (total_input, total_output, total_cache_read, total_cache_write — baselines pre-summed), `avg_events_per_session` | | `GET /api/events?session_id=X` | Event stream incl. `APIError`, `Compaction`, `PreToolUse`/`PostToolUse` — used to localize regressions to specific sessions | | `GET /api/pricing/cost` | `{ total_cost, breakdown[...] }` — total cost to derive cost-per-session | | `GET /api/pricing/cost/{sessionId}` | Per-session cost — used to compare recent vs baseline session cost | | `GET /api/workflows/{sessionId}` | `compaction` (impact), `errorPropagation` (by depth), `effectiveness` — per-session quality signals | | `GET /api/sessions?limit=N` | Sessions with `started_at`, `cost`, `metadata` — to bucket sessions into time windows | ## Report Sections ### 1. Windowing Split history into a *...