{"uid":"cap_K30zRrxb86343jcRYJSsj","slug":"hello-world-x402-vercel-app-00dd0b29","name":"hello-world-x402 Echo Endpoint","description":"Returns the submitted payload verbatim after a required exact USD Coin payment on network eip155:8453 (max timeout 300s).","url":"https://hello-world-x402.vercel.app/echo","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"message":{"type":"string","maxLength":1000,"description":"Message to echo - UPDATED max length"},"metadata":{"type":"string","maxLength":200,"description":"Additional metadata - NEW FIELD"},"priority":{"enum":["low","medium","high","critical","urgent"],"type":"string","description":"Priority level - ADDED critical and urgent"}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.001","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.001/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.001","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_m4DSTwZ5BYUD5J8b1LbzA","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.001","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns the submitted payload verbatim (message, metadata, priority) after a $0.001 USDC micropayment on Base (eip155:8453)","exampleAgentPrompt":"Echo back the message 'Hello from my agent' with metadata 'test-run-1' and priority level medium — this is a paid echo test using USDC on Base.","exampleUseCases":null,"resultDescription":"The exact submitted payload returned verbatim: the message string, metadata string, and priority enum value, unchanged from input.","failureModes":["Payment not provided or incorrect amount — 402 Payment Required response","Payment on wrong network (not eip155:8453) — payment rejected","Request exceeds 300 second timeout — timeout error","Message exceeds 1000 character maxLength — validation error","Metadata exceeds 200 character maxLength — validation error","Invalid priority enum value — schema validation error"],"whenToPreferThis":"Use this endpoint when you need to test or demonstrate the x402 micropayment protocol on the Base network (eip155:8453) with a trivial, side-effect-free operation. Ideal for integration testing of payment flows, verifying that USDC micropayments of $0.001 work end-to-end, or confirming payload integrity through a paid API boundary.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T12:38:03.366Z","isFirstParty":false}