{"uid":"cap_0NRyjsp9Qa8iT17bCvaxq","slug":"x402-testbed-echo-endpoint-6e916561","name":"x402-Testbed Echo Endpoint","description":"x402 test endpoint (GET) — echo for testing an x402 client with query params only. Returns what it received. Query param expectStatus=500 makes it fail with 500 BEFORE any payment is taken (tests your client error path and proves a 5xx is never treated as paid).","url":"https://health-api.tail11a58f.ts.net/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":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","properties":{"expectStatus":{"type":"integer","description":"Set 500 to test post-settlement failure"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"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_GofyDgEUTD3f-6ufcPGcr","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":"Echoes back GET request query parameters for testing x402 payment client integration, with optional 500 error injection before payment settlement.","exampleAgentPrompt":"Send a test GET request to the x402 echo endpoint so I can verify my payment client is working correctly — just echo back what was sent, no error injection needed.","exampleUseCases":[{"title":"Basic x402 client smoke test","prompt":"Make a simple paid GET call to the x402 echo endpoint and show me what it echoed back — I just want to confirm my client can complete a real x402 payment and get a response."},{"title":"Pre-payment 500 error path test","prompt":"Hit the x402 echo endpoint with expectStatus set to 500 so I can verify my client correctly handles a server error that fires before any payment is taken — I need to confirm a 5xx is never recorded as a paid call."},{"title":"Cheapest live x402 integration check","prompt":"Run the smallest possible paid x402 test request against the echo endpoint for me — I want a live end-to-end confirmation that my client negotiates the 402, pays, and receives the echo for just $0.001 USDC."}],"resultDescription":"Returns an echo of the received GET request including query parameters as structured JSON; if expectStatus=500 is supplied, returns an HTTP 500 error response before any payment settlement occurs, allowing the caller to inspect the pre-payment failure path.","failureModes":["expectStatus=500 triggers a 500 Internal Server Error before payment is processed","Missing or malformed query parameters may result in an empty echo body","Network timeouts on the Tailscale-hosted endpoint if the host is offline","x402 payment negotiation failure if client does not support the protocol correctly","402 Payment Required returned if payment credentials are absent or invalid"],"whenToPreferThis":"Choose this endpoint when you need a live, real-money x402 integration test at the lowest possible cost ($0.001 USDC), especially when verifying that your x402 client correctly handles both the happy-path echo response and the pre-payment 5xx error path. Prefer it over mock or sandbox endpoints when you need to confirm end-to-end payment flow with a real facilitator.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-31T18:39:21.553Z","isFirstParty":false,"canonicalSlug":"x402-testbed-echo-endpoint-6e916561"}