# httpay.xyz x402 Ecosystem Index

> httpay.xyz x402 Ecosystem Index is a paid API for AI agents from httpay.xyz, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-14).

Returns a complete index of all x402 pay-per-call services, endpoints, prices, and facilitators across the ecosystem for AI agent discovery

## Facts

- Endpoint: POST https://httpay.xyz/api/x402-index
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/httpay-xyz-x402-ecosystem-index-1d6f3d05
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_-1UA9Mbu9fx3cnUcNgCn6

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

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability httpay-xyz-x402-ecosystem-index-1d6f3d05 -d '<json body>'
```

Example prompt: Show me the full catalog of x402 pay-per-call APIs available on Base — I want to see all services, what they cost in USDC, and which ones cover token intelligence or DeFi yields so I can pick one to call.

## When to prefer this

Use this endpoint when an AI agent needs to discover what x402-compatible APIs exist before deciding which one to call — it is the canonical discovery/index endpoint for the entire x402 ecosystem, covering 300+ services with pricing data, making it ideal for dynamic service selection, cost comparison, and capability discovery without needing pre-existing API keys or subscriptions.

## Known failure modes

- Payment not included or invalid x402 USDC payment on Base returns 402 Payment Required
- Network issues reaching httpay.xyz return 5xx errors
- Index may be stale if underlying services have changed since last crawl

## How this service works

Complete x402 ecosystem index — all known services, endpoints, prices, facilitators, and price comparisons. THE discovery endpoint for AI agents finding x402 services.

## Output

A comprehensive JSON index listing all known x402 ecosystem services including native endpoints and Universal Gateway proxied services, with pricing, facilitator details, and price comparisons — effectively a directory of every pay-per-call API available via the x402 protocol on Base.

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "description": "Complete x402 ecosystem index — all known services, endpoints, prices, facilitators, and price comparisons. THE discovery endpoint for AI agents finding x402 services."
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/httpay-xyz-x402-ecosystem-index-1d6f3d05/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from httpay.xyz](https://www.zero.xyz/host/httpay.xyz/llms.txt)