# Change Sentinel

> Configure alerts for ranking shifts, traffic changes, technical breaks, and competitor moves. 监控预警/变化哨兵

- Skill: `excelle/change-sentinel` (Agent Skill)
- Install (CLI): `npx skillmds@latest add excelle/change-sentinel`
- Raw SKILL.md: https://api.skillmd.com/api/skills/excelle/change-sentinel/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- License: MIT
- Author: excelle (https://skillmd.com/u/excelle)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/excelle/change-sentinel

---


# Change Sentinel

Sets up monitoring for the metrics that matter: ranking drops, traffic anomalies, technical failures, and competitor movements. Early detection prevents disaster.

## Quick Start

```
Set up alerts for ranking drops on [domain]
```

```
Monitor traffic anomalies for [URL]
```

```
Alert me when competitors publish content on [topic]
```

## Engine Contract

- **Reads**: domain, metrics to monitor, thresholds, alert destinations
- **Writes**: alert configuration plan with thresholds and response playbooks
- **Promotes**: active alert rules and baseline thresholds to hot cache
- **Next handoff**: signal packet with monitoring specs

## Instructions

Run three phases:

1. **Select Metrics** — choose what to watch: position drops >5 places, traffic drops >20%, 4xx/5xx spikes, Core Web Vitals regression, lost backlinks, new competitor content, AI citation loss
2. **Set Thresholds** — define trigger levels and cooldown periods to avoid alert fatigue
3. **Response Playbook** — for each alert type, document the first diagnostic step and who responds

## Recommended Alert Rules

| Alert | Threshold | Response |
|-------|-----------|----------|
| Ranking drop | >5 positions for top 10 keyword | Run page-diagnostics + content-refresh |
| Traffic drop | >20% vs same day last week | Check index status + technical health |
| Technical error | >10 5xx errors/ hour | Investigate server + deployment |
| CWV regression | Any metric moves to "Needs Improvement" | Audit page speed + fix list |
| Competitor content | New page published on tracked topic | Run landscape-scan + query-mapping |
| AI citation loss | Citation disappears from tracked query | Refresh content + check accuracy |

## Next Best Engine

- **Primary**: [signal-reporter](track/signal-reporter/SKILL.md) — build periodic reports from alert data
- **Alternatives**: [position-tracker](track/position-tracker/SKILL.md), [site-health-audit](refine/site-health-audit/SKILL.md)