# x402 Pre-Payment Check

> x402 Pre-Payment Check is a paid API for AI agents from x402op-edge-39830b.fly.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-19).

Checks an x402 endpoint's live 402 response, compares pricing to market norms, and returns a verdict (ok/caution/avoid) with usage data before you pay

## Facts

- Endpoint: POST https://x402op-edge-39830b.fly.dev/p/x402-check?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-19
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/x402-pre-payment-check-0704d375
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Ue0mARnH-5pVlgaxwaFTQ

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 x402-pre-payment-check-0704d375 -d '<json body>'
```

Example prompt: Before I pay anything, check this x402 endpoint for me — run a GET pre-payment check on https://api.example.com/some-resource and tell me if it's safe, how the price compares to similar services, and how many people have actually used it.

## When to prefer this

Use this endpoint whenever an AI agent or workflow is about to pay an unfamiliar x402 resource for the first time, especially when the seller is unknown, the price seems unusual, or automated trust decisions are required. It is specifically designed for the x402 protocol ecosystem and combines live probing with Coinbase Bazaar market data — making it more authoritative than generic URL checkers or manual research for x402 payment decisions.

## Known failure modes

- Target URL is not a valid x402 endpoint (returns non-402 response)
- Target URL is unreachable or times out
- Unknown market category makes price comparison unavailable
- No Bazaar usage data found for new or obscure endpoints
- Invalid or missing URL parameter returns 400 error

## How this service works

Before paying an unknown x402 endpoint, ask for a verdict. Checks the live 402 response without paying, compares the price with its market category, shows real usage from the Coinbase Bazaar (payers, repeat buyers, last payment) and the seller's footprint, and returns ok, caution or avoid with reasons.

## Output

A structured verdict of 'ok', 'caution', or 'avoid' with supporting reasons, including: live 402 response details, price vs. market category comparison, Coinbase Bazaar usage stats (number of payers, repeat buyers, last payment date), and the seller's on-chain footprint.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "url": {
   "type": "string",
   "description": "Absolute http(s) URL of the x402 resource you consider paying"
  },
  "method": {
   "enum": [
    "GET",
    "POST"
   ],
   "type": "string",
   "default": "GET",
   "description": "HTTP method of that resource"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/x402-pre-payment-check-0704d375/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402op-edge-39830b.fly.dev](https://www.zero.xyz/host/x402op-edge-39830b.fly.dev/llms.txt)