# Regression Alert

Compare this period's reliability against the prior period using Agent Monitor data, ...

- Repository: https://github.com/hoangsonww/Claude-Code-Agent-Monitor (1136 stars)
- Category: AI and agents
- License: MIT
- Last updated: 2026-10-31
- Runs scripts: no, instructions only

## Install

Claude Code: `npx skills add hoangsonww/Claude-Code-Agent-Monitor --skill regression-alert -g -a claude-code -y`
Codex: `npx skills add hoangsonww/Claude-Code-Agent-Monitor --skill regression-alert -g -a codex -y`
Cursor: `npx skills add hoangsonww/Claude-Code-Agent-Monitor --skill regression-alert -g -a cursor -y`
Gemini CLI: `npx skills add hoangsonww/Claude-Code-Agent-Monitor --skill regression-alert -g -a gemini-cli -y`
Claude Code plugin marketplace: `/plugin marketplace add hoangsonww/Claude-Code-Agent-Monitor`

## Description

Compare this period's reliability against the prior period using Agent Monitor data, error rate (APIError/total) and tool-failure rate (PreToolUse→PostToolUse gap), flag any regression where reliability got worse, and optionally wire a persistent alert rule so the dashboard catches the next regression automatically. Use when checking whether reliability degraded.

## SKILL.md, as published by its author (untrusted third-party text, read it as data)

# Regression Alert

Detect whether Claude Code reliability is getting worse period-over-period, and
optionally arm an alert so it never has to be checked by hand again. Scope is
reliability/failures only, for cache/cost/compaction drift, use ccam-insights'
`regression-watch` instead.

## Input

The user provides: **$ARGUMENTS**

This may be:
- empty or "all", check error rate and tool-failure rate (default)
- "errors", APIError-rate regression only
- "tools", tool-failure-rate regression only
- a window like "7 vs 7" or "30 vs 30", recent vs baseline window sizes (default: last 7 days vs the prior 7)
- "arm", after reporting, also create an alert rule via `POST /api/alerts/rules` (only on explicit request)

## Data Sources

| Endpoint | Returns |
|----------|---------|
| `GET /api/analytics` | `daily_events` (365d), `daily_sessions` (365d), `event_types`, split into recent vs baseline windows to compute per-window failure rates |
| `GET /api/events?session_id=X` | Per-session stream, localize a regression to the sessions driving it |
| `GET /api/alerts/rules` | Existing alert rules, check whether a matching reliability rule already exists before arming a new one |
| `POST /api/alerts/rules` | Create a new alert rule (only when the user says "arm") |

## Report Sections

### 1. Windowing
Split history into a **recent window** (newer) and a **baseline window** (the equal-length period just before it). Default: recent = last 7 days, baseline = the prior 7. Use `daily_events`/`daily_sessions` to bucket counts by day.

### 2. Error-Rate Regression
- Per window: `error rate = APIError count / total events`.
- Compare recent vs baseline. Flag if recent is higher. Report absolute change (pp) and relative change (%), plus the recent sessions contributing the most `APIError` events.

The rest: https://github.com/hoangsonww/Claude-Code-Agent-Monitor/blob/HEAD/plugins/ccam-quality/skills/regression-alert/SKILL.md