{"x402Version":1,"scheme":"fb-exact","network":"fractal-mainnet","asset":"FB","positioning":"The Fractal rail for agent payments — priced in FB, readable in $, settled UTXO-native.","endpoints":{"price":"/v1/price/fb","tools":"/v1/tools.json","discover":"/v1/discover","verify":"/v1/verify","verifyBip322":"/v1/verify-bip322","receipts":"/v1/receipts/:txid","buildPayment":"/v1/build-payment","wellKnown":"/.well-known/x402","wellKnownJson":"/.well-known/x402.json","mcp":"/mcp.json"},"settlement":{"model":"2-output UTXO","prefer":"X-PAYMENT-RAWTX","headers":["X-PAYMENT-NONCE","X-PAYMENT-TXID","X-PAYMENT-RAWTX","X-PAYMENT-BINDING","X-PAYMENT-PAYER"],"custody":"non-custodial","verify":"locally verified outs from rawTx; txid must match rawTx; payer proven from inputs/change","payer":"X-PAYMENT-PAYER accepted only if it appears as an input owner of the rawTx (change-only is not enough)"},"pricing":{"primary":"sats","display":"usd_approx via FB/USDT spot (MEXC + CoinEx median)","note":"USD is estimate only. Settlement is always FB sats."},"buyerSpend":"/v1/buyers/:address/spend"}