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x402 Pre-Payment Check
x402
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
Price / call$0.002
Success—
StatusUnknown
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.
Example use cases
Due diligence before first x402 payment
“I'm about to pay an x402 API I've never used before at https://api.someservice.com/data — can you check it first with a GET and tell me if the price seems fair and whether real people have actually paid it?”
Comparing unknown seller to market rates
“I found an x402 endpoint at https://unknown-provider.fly.dev/analyze that wants to charge me, but I don't know if that's a reasonable price for what it does — can you do a pre-payment check on it via GET and compare it to what similar services charge?”
Automated agent payment guardrail
“My workflow is about to call a POST x402 endpoint at https://thirdparty.io/transform — before it pays, run a safety check on it and flag it if it's priced way above market or has no real usage history.”
Technical details
Endpoint
POSThttps://x402op-edge-39830b.fly.dev/p/x402-check?utm_source=zero.xyzWhen to prefer
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.
Side effects
- 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
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| url | string | Absolute http(s) URL of the x402 resource you consider paying |
| method | string | HTTP method of that resource |
Tags
x402
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