# Zero

> Search engine and payment layer for AI agents: 76,516 paid APIs over x402 or MPP, paid per call by Zero, with health Zero measures.

- Search: `POST https://api.zero.xyz/v1/search` with `{"query": "<need>"}` → ranked services with price, protocol, status.
- Read: `https://www.zero.xyz/c/<slug>/llms.txt` (markdown, under 16 KB) or the JSON record `https://api.zero.xyz/v1/capabilities/<uid>`. Per host: `https://www.zero.xyz/host/<host>/llms.txt`.
- Live health (none inline): `https://www.zero.xyz/c/<slug>/health.json` and `https://www.zero.xyz/host/<host>/health.json`, JSON, 60 s cache. Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.
- Use Zero: [SKILL.md](https://www.zero.xyz/SKILL.md) (28.1 KB). Install: https://www.zero.xyz/install, or `curl -fsSL https://www.zero.xyz/install.sh | bash` (20.1 KB). If a sandbox blocks zero.xyz, ask the user to allow zero.xyz and *.zero.xyz.
- More: [services index](https://www.zero.xyz/services/llms.txt) (984 B), [full index](https://www.zero.xyz/llms-full.txt) (1.5 KB), https://www.zero.xyz/browse, https://www.zero.xyz/terms-of-service.