{"uid":"cap_RyHTv7k3rxcdy2YleJ68l","slug":"lumen-x402-header-lint-decoder-26259465","name":"Lumen x402 Header Lint & Decoder","description":"Decode and lint an x402 PAYMENT-REQUIRED / PAYMENT-SIGNATURE / PAYMENT-RESPONSE header (base64 or JSON): kind, decoded object, errors/warnings (CAIP-2, checksum, EIP-712 domain, expiry).","url":"https://lumenworks-x402-decoder.onrender.com/v1/x402/lint?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":null,"responseSchema":{"type":"json","example":{"ok":true,"kind":"PAYMENT-REQUIRED","issues":[],"decoded":{"accepts":[{"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","extra":{"name":"USD Coin","version":"2"},"payTo":"0xee9790cB3960952F585379F831a89b4e00B4029A","amount":"2000","scheme":"exact","network":"eip155:8453","maxTimeoutSeconds":120}],"resource":{"url":"https://lumenworks-x402-decoder.onrender.com/v1/tx/explain"},"x402Version":2}}},"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.002","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":"$0.002/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.002","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_ei3nX9Kxwxnp5MUSdSUAH","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.002","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Decodes and lints x402 PAYMENT-REQUIRED, PAYMENT-SIGNATURE, or PAYMENT-RESPONSE headers (base64 or JSON), returning the header kind, decoded object, and any errors or warnings about CAIP-2, checksum, EIP-712 domain, or expiry.","exampleAgentPrompt":"Can you decode and lint this x402 PAYMENT-REQUIRED header for me and tell me if there are any errors or warnings — especially around the CAIP-2 network, EIP-712 domain, and expiry? Here's the base64 value: eyJ4NDAyVmVyc2lvbiI6Mn0=","exampleUseCases":[{"title":"Debugging a malformed payment header","prompt":"I'm getting a weird x402 PAYMENT-REQUIRED header back from an API and I'm not sure if it's valid — can you decode it and tell me what's wrong with it? The raw base64 is eyJ4NDAyVmVyc2lvbiI6MiwiYWNjZXB0cyI6W119."},{"title":"Validating EIP-712 domain in a payment signature","prompt":"I just received a PAYMENT-SIGNATURE header and I want to make sure the EIP-712 domain and checksum look right before I accept it — here's the JSON: {\"scheme\":\"exact\",\"network\":\"eip155:8453\",\"asset\":\"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913\"}"},{"title":"Checking x402 header expiry and CAIP-2 compliance","prompt":"Can you lint this x402 PAYMENT-RESPONSE header and let me know whether it's expired and whether the CAIP-2 network identifier is correct? Here's the value: eyJ4NDAyVmVyc2lvbiI6MiwidHlwZSI6InJlc3BvbnNlIn0="}],"resultDescription":"A JSON object with: ok (boolean indicating no critical errors), kind (PAYMENT-REQUIRED, PAYMENT-SIGNATURE, or PAYMENT-RESPONSE), decoded (the full parsed header object including accepts array, resource URL, x402Version, amounts, payTo address, network, scheme, and timeout), and issues (an array of errors and warnings covering CAIP-2 identifiers, address checksums, EIP-712 domain fields, and expiry status).","failureModes":["Invalid base64 input returns decode error","Unrecognized header kind returns unknown type error","Missing required fields in JSON body trigger validation errors in issues array","Network connectivity issues to onrender.com hosting may cause 503 timeouts","Malformed CAIP-2 network string flagged as error in issues but still returns decoded object"],"whenToPreferThis":"Use this endpoint when you need to programmatically validate or debug an x402 HTTP payment header — especially when integrating x402-enabled APIs and want to catch CAIP-2 network mismatches, bad EIP-712 domains, invalid checksums, or expired payment requests before signing or submitting. Prefer this over manual inspection when the header is base64-encoded or when you need structured error reporting.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-11T12:45:13.204Z","isFirstParty":false,"canonicalSlug":"lumen-x402-header-lint-decoder-26259465"}