{"uid":"cap_ihTqj2YngeKrbZNIgWbuK","slug":"evm-bytecode-size-checker-a7e6fb7d","name":"EVM Bytecode Size Checker","description":"Bytecode size of an address across 7 EVM chains - zero means a regular wallet (EOA), non-zero means a contract with the byte count indicating complexity - a fast primitive for agents to distinguish wallets from contracts before interacting. code size, is contract, bytecode size, eoa or contract, contract bytecode, account code","url":"https://api.x402node.dev/chain/code-size","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":["address"],"properties":{"chain":{"type":"string","description":"ethereum, base (default), arbitrum, optimism, polygon, bsc, avalanche"},"address":{"type":"string","description":"Address (required)"}}}},"additionalProperties":false}}},"responseSchema":null,"example":{"request":{"address":"0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984"},"response":{"note":"Bytecode size of an address. 0 = EOA (wallet); >0 = contract. Larger size often = more complex contract. Agents use to know if an address is a contract before interacting.","_hint":"x402 paid endpoints for AI agents — x402node.dev (utilities) · cn402.com (Chinese culture)","chain":"base","source":"rpc","address":"0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984","isContract":true,"codeSizeBytes":2109}},"exampleRequest":{"address":"0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984"},"tags":["x402"],"displayCostAmount":"0.004","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":"$0.004/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.004","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.004","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_wi8Ps_qh6NASbA9jpgb8W","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.004","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns the bytecode size of an address on up to 7 EVM chains, distinguishing EOAs (size=0) from smart contracts (size>0).","exampleAgentPrompt":"Is 0x1f9840a85d5aF5bf1D1762F925BDADdC4201F984 a wallet or a smart contract? Check across all available EVM chains and tell me the bytecode size.","exampleUseCases":null,"resultDescription":"Returns the bytecode size (in bytes) of the given address on each supported EVM chain. A size of 0 means it is a regular wallet (EOA); any non-zero value means it is a deployed smart contract, with the byte count indicating relative complexity. Results are returned per chain.","failureModes":["Invalid or malformed Ethereum address returns an error response","Address not found or chain unavailable may return null or zero for that chain","Unsupported chain identifier returns an error","Network timeout on a specific chain may yield partial results"],"whenToPreferThis":"Use this endpoint when you need to quickly determine whether an Ethereum-style address is a wallet (EOA) or a deployed smart contract before interacting with it programmatically — especially when operating across multiple EVM chains at once. Prefer this over full ABI fetching or Etherscan lookups when you only need a fast binary wallet-vs-contract check plus a rough complexity signal from byte count.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T00:50:21.609Z","isFirstParty":false}