{"uid":"cap_tuNjovH0kZ508-4CB9yRb","slug":"agent-caf-buy-a-round-x402-usdc-payment-4f490ed7","name":"Agent Café — Buy a Round (x402 USDC Payment)","description":"The trusted endpoint where AI agents pay for real — USDC on Base over x402 — and get the receipt to prove it.","url":"https://api.402.coffee/order/buy-a-round","method":"POST","headers":{},"bodySchema":null,"responseSchema":{"type":"json","example":{"tx":"0x…","paid":true,"order":"espresso","amount":"0.10","network":"base","currency":"USDC","receipt_no":"AC-XXXXXX","guestbook_url":"https://402.coffee/wall"}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"100","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"unknown","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"down","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$100/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"100","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"100","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_MWZ1t2VpgRq_A0Q8hlm-v","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"100","costPer":"request","priority":0,"asset":null,"unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Accepts a real USDC payment on Base via x402 and returns a signed receipt proving an AI agent paid for a coffee order.","exampleAgentPrompt":"Buy me a round at Agent Café — send the USDC payment on Base and bring back the receipt number so I can prove you actually paid for it.","exampleUseCases":[{"title":"Prove agent payment capability live","prompt":"I need to demonstrate that you can autonomously make a real on-chain payment — go pay for a coffee at Agent Café with USDC on Base and show me the transaction hash and receipt as proof."},{"title":"Test x402 micropayment in production","prompt":"Run a live test of the x402 payment protocol for me — hit the Agent Café endpoint, pay with USDC on Base, and come back with the receipt number and the guestbook URL so I can verify everything went through."},{"title":"Log verifiable crypto payment receipt","prompt":"Pay for an espresso at Agent Café using USDC on Base and give me the full receipt details — transaction hash, receipt number, and confirmation it's recorded publicly — so I have an on-chain record of the payment."}],"resultDescription":"A JSON object containing the transaction hash (tx), a paid boolean (true), the order name (e.g. 'espresso'), the amount paid ('0.10'), the network ('base'), the currency ('USDC'), a unique receipt number (e.g. 'AC-XXXXXX'), and a guestbook URL where the payment is recorded publicly.","failureModes":["Insufficient USDC balance — payment rejected with 402 status","Invalid or missing x402 payment header — request refused","Network congestion on Base causing transaction delay or timeout","Duplicate payment attempt on same nonce — rejected","Contract or facilitator downtime causing 503 error"],"whenToPreferThis":"Choose this endpoint when you need to demonstrate or execute a real, verifiable on-chain micropayment from an AI agent using USDC on Base via the x402 protocol, and require a cryptographically-backed receipt as proof. It is purpose-built as a live test and showcase endpoint for x402-capable agents, not a simulation.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T15:25:43.092Z","isFirstParty":false}