{"uid":"cap_xBJDerr_7u3KSKx4t1vaY","slug":"x402-payment-challenge-inspector-74c262f6","name":"x402 Payment Challenge Inspector","description":"Read a paid endpoint's 402 challenge without paying it","url":"https://sentinel.rootstuff.io/x402/payment-envelope","method":"GET","headers":{},"bodySchema":{"type":"object","properties":{"url":{"type":"string","description":"The paid http(s) route to probe."},"expected_pay_to":{"type":"string","description":"Optional. Address the challenge should pay to."},"expected_network":{"type":"string","description":"Optional. CAIP-2 network such as eip155:8453."},"expected_amount_usd":{"type":"string","description":"Optional. Price in USD the challenge should carry."}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.02","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":"$0.02/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.02","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_YZeubMHVBnkI7kA2cR3jQ","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.02","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Fetches and returns the 402 payment challenge (payment envelope) from a paid HTTP endpoint without actually paying it","exampleAgentPrompt":"Probe https://api.example.com/premium-data and pull back its x402 payment challenge so I can see the pay-to address, network, and required amount without actually paying.","exampleUseCases":[{"title":"Verify x402 endpoint before integrating","prompt":"Before I build my payment flow, can you inspect the 402 challenge at https://data.myservice.io/report and confirm it expects payment on eip155:8453 and to address 0xAbC123... for $0.10?"},{"title":"Debug failing x402 payment","prompt":"My x402 payment to https://sentinel.rootstuff.io/x402/some-endpoint keeps failing — can you read the raw payment challenge from it so I can see exactly what pay-to address and network it's asking for?"},{"title":"Discover pricing of a paid API","prompt":"I found this paid API at https://thirdparty.ai/api/generate — can you fetch its payment challenge and tell me how much it costs and which wallet and blockchain it pays to?"}],"resultDescription":"Returns the raw x402 payment envelope from the target URL, including the pay-to wallet address, CAIP-2 network identifier, required payment amount in USD, and any other challenge fields — all without executing a payment. May include validation results if expected values were supplied.","failureModes":["Target URL does not return a 402 status (not a paid endpoint)","Target URL is unreachable or times out","Malformed or non-standard x402 challenge returned by target","Expected pay-to address, network, or amount does not match — validation mismatch returned","Invalid URL format provided as input"],"whenToPreferThis":"Use this endpoint when you need to inspect or validate an x402 payment challenge from a paid HTTP endpoint before committing to payment — especially useful for debugging payment flows, verifying pay-to addresses and networks, discovering endpoint pricing, or building x402-aware agents that need to parse challenge parameters dynamically. Prefer this over manually sending HTTP requests when you want a structured, parsed result with optional validation against expected values.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T18:33:34.532Z","isFirstParty":false}