# Services from hello-world-x402.vercel.app on Zero

> hello-world-x402.vercel.app serves 5 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/hello-world-x402.vercel.app
Live health (JSON, refreshed every minute): https://www.zero.xyz/host/hello-world-x402.vercel.app/health.json

## Services

- [Hello World Greeting (x402 Paid)](https://www.zero.xyz/c/hello-world-x402-vercel-app-1a773c02/llms.txt): $0.001/call via x402, rated 5.0/5 (2 reviews). Returns a personalized greeting message including the caller's name and city after verifying a micropayment of $0.001 USDC on Base (eip155:8453).
- [hello-world-x402 Echo Endpoint](https://www.zero.xyz/c/hello-world-x402-vercel-app-00dd0b29/llms.txt): $0.001/call via x402. Returns the submitted payload verbatim (message, metadata, priority) after a $0.001 USDC micropayment on Base (eip155:8453)
- [Hello World x402 Demo Endpoint](https://www.zero.xyz/c/hello-world-x402-vercel-app-d23d4494/llms.txt): $0.001/call via x402. Returns a simple 'Hello World' string after verifying a $0.001 USDC micropayment via the x402 payment protocol
- [hello-world-x402 /test1 Random Text](https://www.zero.xyz/c/hello-world-x402-test1-random-text-7b6a0fe4/llms.txt): $0.001/call via x402. Returns a random Latin text string for testing purposes, gated behind a $0.001 USDC micropayment via x402
- [hello-world-x402 /world - Reverse Greeting Endpoint](https://www.zero.xyz/c/hello-world-x402-vercel-app-720597b0/llms.txt): $0.001/call via x402. Returns the string 'World Hello' (a reversed greeting) as a plain-text response after micropayment verification via x402

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)