regression-watch
Detect quality and efficiency regressions over time using Agent Monitor data — rising error rate (APIError events), falling cache hit rate, growing compaction frequency, and climbing cost-per-session. Splits history into an earlier baseline window and a recent window and reports which metrics are getting worse, by how much, and where. Use when checking whether things are degrading or trending in the wrong direction.
Profile →npx skills add hoangsonww/Claude-Code-Agent-Monitor --skill regression-watch --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
# 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/{se
- Input
- Data Sources
- Report Sections
- 1. Windowing
- 2. Error Rate Regression
- 3. Cache Hit Rate Regression
- 4. Compaction Frequency Regression
- 5. Cost-per-Session Regression
- 6. Verdict
- Output
What does the regression-watch skill do?
Detect quality and efficiency regressions over time using Agent Monitor data — rising error rate (APIError events), falling cache hit rate, growing compaction frequency, and climbing cost-per-session. Splits history into an earlier baseline window and a recent window and reports which metrics are getting worse, by how much, and where. Use when checking whether things are degrading or trending in the wrong direction.
How do I install it?
Run `npx skills add hoangsonww/Claude-Code-Agent-Monitor --skill regression-watch --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From hoangsonww/Claude-Code-Agent-Monitor, a repository with 869 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.