{"uid":"cap_9HzIY8nnaAGDoVrKt8B7Q","slug":"api-x402node-dev-ecf3e94c","name":"EVM Calldata & Transaction Decoder","description":"Decode EVM calldata or a Base tx hash into a readable function call: signature, selector, and decoded typed arguments. Search terms: calldata decoder, ABI decode, function selector 4byte, transaction decoder, EVM tx decode. Accepts payment on Base or Solana — either network works.","url":"https://api.x402node.dev/chain/tx-decode","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","required":["data","tx"],"properties":{"to":{"type":"string","description":"Target format (optional)"},"tx":{"type":"string","description":"Tx (required)"},"data":{"type":"string","description":"Data (required)"},"txhash":{"type":"string","description":"Txhash (optional)"},"calldata":{"type":"string","description":"Calldata (optional)"}}}},"additionalProperties":false}}},"responseSchema":null,"example":{"request":{"data":"0xa9059cbb000000000000000000000000742d35cc6634c0532925a3b844bc9e7595f42bd20000000000000000000000000000000000000000000000000000000000000001"},"response":{"raw":{"to":null,"from":null,"value":null,"calldata_bytes":68},"_hint":"x402 paid endpoints for AI agents — x402node.dev (utilities) · cn402.com (Chinese culture)","network":"base","selector":"0xa9059cbb","decode_error":null,"decoded_args":[{"name":null,"type":"address","value":"0x742d35Cc6634C0532925a3B844bC9E7595f42Bd2"},{"name":null,"type":"uint256","value":"1"}],"other_candidates":[],"function_signature":"transfer(address,uint256)"}},"exampleRequest":{"data":"0xa9059cbb000000000000000000000000742d35cc6634c0532925a3b844bc9e7595f42bd20000000000000000000000000000000000000000000000000000000000000001"},"tags":["x402"],"displayCostAmount":"0.05","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"settled","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":"$0.05/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.05","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.05","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_MnHmLMnOtpzwUv944sxDz","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.05","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Decodes EVM calldata or a Base transaction hash into a human-readable function call, including the function signature, 4-byte selector, and typed decoded arguments.","exampleAgentPrompt":"Can you decode this Base transaction hash 0x3f7a...b29c and tell me what function was called, the 4-byte selector, and what the typed arguments were?","exampleUseCases":null,"resultDescription":"Returns the decoded function signature (e.g. transfer(address,uint256)), the 4-byte selector, and all decoded typed arguments with their names, types, and values — making raw calldata or a tx hash fully human-readable.","failureModes":["Unknown function selector not found in 4byte.directory or embedded ABI — returns unresolvable selector error","Invalid or malformed calldata hex — returns parse error","Transaction hash not found on Base — returns not found error","Calldata too short to contain a valid selector — returns invalid input error","Network timeout fetching transaction from Base RPC — returns timeout error"],"whenToPreferThis":"Use this endpoint when you need to interpret raw EVM calldata or a Base chain transaction hash without manually providing an ABI — it resolves function signatures via selector databases and decodes typed arguments automatically. Prefer it over manual ABI decoding when the ABI is unknown or when you need a quick, human-readable breakdown of a contract interaction.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T00:52:11.513Z","isFirstParty":false}