x402 Doctor preflight
Check an x402 endpoint before paying it: go, caution or no_go with reason codes. Reads the endpoint's 402 challenge without paying it and checks every payment option (network, token, amount, whether the payout account can receive), the price against the seller's OpenAPI, the payout address against the OFAC sanctions list, and the endpoint's 30-day record in the x402 Trust Index. GET ?url=<endpoint>&max_usd=<budget>.
1 route settlement-verified · $0.001 USDC/request · 1 endpoint · Verification · base network · x402 protocol
Verified routes
GET /api/v1/preflight· $0.001 · 2026-10-26 · receipt
Other routes are unverified.
Networks: Base (settlement-verified)
Discovery is free. Agents search the catalogue here. Payment happens on the listing 402, not on PayAPI.
url https://payapi.market/mcpListing facts
- Provider
- Fizzl
- Hosted at
x402-doctor.fizzl.eu- Category
- Verification
- Price
- $0.001 USDC per request
- Payment networks
- Base
- Settlement-verified
- 1 route, last checked 2026-10-26
- Listed on PayAPI Market
- 2026-10-25
Try x402 Doctor preflight
Call a verified route without paying first. The server should answer HTTP 402 Payment Required with the price, the USDC asset, the network and the wallet to pay. An x402 client pays that amount on Base and retries with the payment header.
curl -i "https://x402-doctor.fizzl.eu/api/v1/preflight?url=https://ichimoku-signal.fizzl.eu/signal/BTC-USDT"About this API
x402 Doctor preflight is listed in the Verification category with pricing at $0.001 USDC/request. One route has been settlement-verified by PayAPI Market on 2026-10-26. View receipt on Basescan.
Payments settle on base in USDC via the x402 protocol. AI agents discover this API through the PayAPI Market MCP server and pay per request without API keys or accounts.
This API exposes 1 endpoint.
Questions about this API
What does x402 Doctor preflight do?
Check an x402 endpoint before paying it: go, caution or no_go with reason codes. Reads the endpoint's 402 challenge without paying it and checks every payment option (network, token, amount, whether the payout account can receive), the price against the seller's OpenAPI, the payout address against the OFAC sanctions list, and the endpoint's 30-day record in the x402 Trust Index. GET ?url=<endpoint>&max_usd=<budget>. It is provided by Fizzl.
How much does x402 Doctor preflight cost?
x402 Doctor preflight is priced at $0.001 USDC per request, paid per call with no subscription. PayAPI Market paid 0.001 USDC for one call to /api/v1/preflight when it verified the listing. The exact amount for each call is in the HTTP 402 response before any money moves.
Do I need an API key or account to use x402 Doctor preflight?
No. x402 Doctor preflight uses the x402 protocol, so an agent pays per request in USDC on Base and gets the response, with no API key, account or signup.
Has x402 Doctor preflight been verified?
Yes, 1 route. PayAPI Market paid for a real call from its own wallet, received real data back and recorded the USDC settlement on-chain, most recently on 2026-10-26.
How does an AI agent find x402 Doctor preflight?
Through the free PayAPI Market MCP server at https://payapi.market/mcp, using search_apis or get_api, or over plain HTTP at https://payapi.market/agent/search. Discovery is free; the agent pays the provider directly on the listing's own 402.
More Verification APIs · Browse the marketplace · List your own API
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