{"uid":"cap_UUpL4V22YCVYz6nRH525I","slug":"the-latent-lounge-x402-echo-cab9f026","name":"The Latent Lounge x402 Echo","description":"Test your x402 client for a tenth of a cent: a real, non-refundable USDC payment on Base mainnet that returns the details of the payment you just made — x402 version, header, scheme, network, payer, amount, validity window and nonce — with the settlement receipt in the response headers. Built for debugging agents, wallets and x402 integrations.","url":"https://www.thelatentlounge.com/api/x402/echo?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"type":"string","const":"GET"},"queryParams":{"type":"object","properties":{}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string","const":"json"},"example":{"type":"object","properties":{"payer":{"type":"string"},"amount":{"type":"string","description":"Atomic USDC units (6 decimals)."},"header":{"type":"string"},"network":{"type":"string"},"x402Version":{"type":"integer"}}}}}}},"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_E74Fv-r47e1kPa78rtVXC","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 a mirror of your x402 USDC payment details and settlement receipt headers for debugging x402 protocol integrations on Base mainnet.","exampleAgentPrompt":"Send a real x402 USDC payment to the Latent Lounge echo endpoint on Base mainnet and show me everything it echoes back — the payer address, amount, header, nonce, validity window, and settlement receipt.","exampleUseCases":[{"title":"Debugging x402 client before production","prompt":"I just built an x402 payment client and want to make sure it's sending the right headers — can you hit the Latent Lounge x402 echo endpoint and show me exactly what payer address, amount in atomic units, nonce, and validity window it's seeing on their end?"},{"title":"Verifying x402 wallet integration on Base","prompt":"I need to confirm my wallet is correctly signing x402 payments on Base mainnet — can you make a real USDC micropayment to the Latent Lounge echo endpoint and show me the full echo response including scheme, network, and the settlement receipt from the headers?"},{"title":"Checking x402 receipt for agent payment flow","prompt":"Before I wire up my AI agent to pay for API calls, I want to see a real x402 settlement receipt — can you call the Latent Lounge echo endpoint with a tenth-of-a-cent USDC payment and show me what the receipt headers look like?"}],"resultDescription":"A JSON object echoing the x402 payment just made, including x402Version (integer), header (string), scheme, network, payer address, amount in atomic USDC units (6 decimals), validity window, and nonce. The HTTP response headers also contain the settlement receipt confirming on-chain settlement.","failureModes":["Missing or malformed x402 payment header returns 402 Payment Required","Insufficient USDC balance causes payment failure before the endpoint is reached","Wrong network (not Base mainnet) causes payment rejection","Expired validity window in payment header causes rejection","Invalid nonce or replayed nonce causes rejection"],"whenToPreferThis":"Choose this endpoint when you need to verify that your x402 client, wallet, or agent is correctly constructing and transmitting x402 payment headers on Base mainnet with real USDC. It is the canonical low-cost ($0.001) integration smoke-test for x402 — cheaper and faster than building a mock server, and it returns a real settlement receipt so you can confirm the full payment lifecycle works end-to-end.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-12T18:42:23.498Z","isFirstParty":false,"canonicalSlug":"the-latent-lounge-x402-echo-cab9f026"}