{"uid":"cap_uiW73jCUa8SYlfAwOB9DC","slug":"web3-tools-evm-calldata-splitter-03b4a1e9","name":"Web3 Tools – EVM Calldata Splitter","description":"Split EVM calldata into its 4-byte selector and 32-byte words, naming common ERC-20/721 calls and spotting addresses.","url":"https://web3-tools.x402tookit.com/calldata-split?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","required":["data"],"properties":{"data":{"type":"string","description":"Calldata hex, with or without 0x"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object","properties":{"asOf":{"type":["null","string"]},"words":{"type":["array","null"],"items":{"type":"object","properties":{"hex":{"type":["null","string"]},"index":{"type":["null","number"]},"address":{"type":["null","string"]},"asUint256":{"type":["null","string"]},"isMaxUint256":{"type":["boolean","null"]},"looksLikeAddress":{"type":["boolean","null"]}}}},"source":{"type":["null","string"]},"reasons":{"type":["array","null"],"items":{"type":"string"}},"summary":{"type":["null","string"]},"verdict":{"type":["null","string"]},"degraded":{"type":["boolean","null"]},"selector":{"type":["null","string"]},"wordCount":{"type":["null","number"]},"disclaimer":{"type":["null","string"]},"notChecked":{"type":["array","null"],"items":{"type":"string"}},"totalBytes":{"type":["null","number"]},"argumentBytes":{"type":["null","number"]},"trailingBytes":{"type":["null","number"]},"knownSignature":{"type":["null","string"]},"wordsTruncated":{"type":["boolean","null"]},"unlimitedApprovalSuspected":{"type":["boolean","null"]}}}}}}},"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_rQylyoq9xhu2IRdFvrxme","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":"Splits raw EVM calldata into its 4-byte function selector and 32-byte argument words, identifies known ERC-20/ERC-721 function signatures, and flags embedded Ethereum addresses.","exampleAgentPrompt":"Can you split this EVM calldata for me and tell me what function it's calling and whether any of the arguments look like Ethereum addresses? The calldata is 0xa9059cbb000000000000000000000000d8da6bf26964af9d7eed9e03e53415d37aa960450000000000000000000000000000000000000000000000000de0b6b3a7640000","exampleUseCases":[{"title":"Auditing a suspicious transaction","prompt":"I've got the input data from a transaction I'm suspicious about — can you split this calldata and tell me what function it's invoking and whether there are any addresses in the arguments? Here it is: 0x23b872dd000000000000000000000000ab5801a7d398351b8be11c439e05c5b3259aec9b000000000000000000000000d8da6bf26964af9d7eed9e03e53415d37aa960450000000000000000000000000000000000000000000000000de0b6b3a7640000"},{"title":"Detecting unlimited token approvals","prompt":"Before I sign this transaction, can you parse its calldata and check if it looks like an unlimited token approval? The hex is 0x095ea7b3000000000000000000000000def1c0ded9bec7f1a1670819833240f027b25effffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff"},{"title":"Debugging a failed contract call","prompt":"My contract call failed and I need to understand what was actually sent — can you break down this calldata into its selector and 32-byte words so I can see what arguments were encoded? Data: 0x70a08231000000000000000000000000d8da6bf26964af9d7eed9e03e53415d37aa96045"}],"resultDescription":"Returns the 4-byte function selector, a human-readable known signature if recognized (e.g. 'transfer(address,uint256)' for ERC-20), an array of 32-byte argument words each annotated with its index, hex value, decoded uint256, and whether it looks like an Ethereum address, plus total byte counts, trailing byte count, an unlimited-approval flag, a summary verdict, and any applicable disclaimers.","failureModes":["Invalid or non-hex input returns an error","Calldata shorter than 4 bytes cannot yield a selector","Unknown selectors return null for knownSignature","Truncated word list when calldata is very long (wordsTruncated: true)","Missing required 'data' query parameter returns a validation error"],"whenToPreferThis":"Use this endpoint when you need to programmatically decode raw EVM transaction input data without a full ABI — especially when you want automatic identification of common ERC-20/ERC-721 calls, embedded address detection, and unlimited-approval flagging in a single lightweight call. Prefer it over a full ABI decoder when you don't have the ABI or just need quick structural insight into what a transaction is doing.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-21T07:20:32.448Z","isFirstParty":false,"canonicalSlug":"web3-tools-evm-calldata-splitter-03b4a1e9"}