Send the request without payment; the API answers HTTP 402 with the payment requirements (x402 v2: the PAYMENT-REQUIRED header; MPP: WWW-Authenticate: Payment challenges). Sign a payment for that amount, send the request again with it (x402: PAYMENT-SIGNATURE header; MPP: Authorization: Payment), and the API answers 200 with the data. At P0 you can rehearse the whole flow on https://x402-bazaar-rank.x402-bazaar-rank-worker.workers.dev/x402/test for $0.001.
Data as of 2026-10-25 · Source: P0 payment requirements (this site's 402 responses)
| Step | x402 v2 | MPP (Machine Payments Protocol) |
|---|---|---|
| 1. Ask | GET the endpoint with no payment | GET the endpoint with no payment |
| 2. Receive the price | HTTP 402, PAYMENT-REQUIRED header (scheme exact, network and asset listed) | HTTP 402, one or more WWW-Authenticate: Payment challenges (method evm, intent charge, USDC) |
| 3. Pay | Sign a transfer authorisation for the amount | Sign an EIP-3009 authorisation for the amount (credential type authorization) |
| 4. Retry | Same request plus the PAYMENT-SIGNATURE header | Same request plus Authorization: Payment <credential> |
| 5. Receive | HTTP 200 and the data | HTTP 200, the data and a Payment-Receipt |
/x402/test - $0.001 per call: a real paid call that echoes your request and reports how it was settled (test target for clients, wallets and facilitators)/pay: free page: pay without an x402 client by a direct transferPaid routes answer HTTP 402 with the payment requirements until paid over x402 or MPP (no account or key); see how to pay, pay without a client, OpenAPI. The figures on this page are also at ?format=json.
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