# Services from spend.crestsystems.ai on Zero

> spend.crestsystems.ai serves 2 paid API services for AI agents, indexed by Zero. Each is callable per call with payment handled by Zero.

Canonical page: https://www.zero.xyz/host/spend.crestsystems.ai
Live health (JSON, refreshed every minute): https://www.zero.xyz/host/spend.crestsystems.ai/health.json

## Services

- [Crest Systems x402 Anomaly Detection](https://www.zero.xyz/c/spend-crestsystems-ai-9c367712/llms.txt): $0.050000/call via x402. Detects cross-service anomalies in the x402 payment ecosystem including revenue spikes, volume anomalies, whale activity, and z-score deviations over a configurable lookback window
- [x402 Market Overview API](https://www.zero.xyz/c/spend-crestsystems-ai-c7ff0e86/llms.txt): $0.010000/call via x402. Returns a real-time overview of the x402 payment ecosystem including top services by revenue, price distribution, hourly volume, and ecosystem health score.

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

- [Zero catalog index](https://www.zero.xyz/llms.txt)