{"uid":"cap_u99Ls8Jkj_B7S_da3WIb_","slug":"evm-address-type-checker-contract-vs-eoa-551d085e","name":"EVM Address Type Checker (Contract vs EOA)","description":"Is this address a contract or an externally-owned account — Genesis402 / UnyKorn Operator Network","url":"https://twin.unykorn.org/evm-code?utm_source=zero.xyz","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"params":{"type":"object","properties":{"block":{"type":"string"},"chain":{"enum":["ethereum","base","polygon","arbitrum","optimism","bsc","avalanche","gnosis","linea","scroll"],"type":"string"},"address":{"type":"string","pattern":"^0x[0-9a-fA-F]{40}$"}}}}},"responseSchema":{"type":"json","example":{"ok":true,"type":"evm-code","receipt":{"tx_hash":"0x<64hex>","amount_usd":0.002,"receipt_id":"g402-<16hex>"},"generated_at":"<iso8601>"}},"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_5JJWDzVCL9gG_NTwSDUA-","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":"Determines whether an Ethereum-compatible address is a smart contract or an externally-owned account (EOA) on a specified EVM chain and block","exampleAgentPrompt":"Is the address 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 a smart contract or a regular wallet on Ethereum mainnet?","exampleUseCases":[{"title":"Validate DeFi counterparty type","prompt":"Before I interact with 0xdAC17F958D2ee523a2206206994597C13D831ec7 on Ethereum, can you check whether it's a smart contract or just a regular wallet address?"},{"title":"Classify address before airdrop","prompt":"I'm about to send tokens to 0x3fC91A3afd70395Cd496C647d5a6CC9D4B2b7FAD on Arbitrum — can you confirm if that's a contract or an EOA so I know how to handle it?"},{"title":"Security check on suspicious address","prompt":"Someone sent me a transaction from 0x00000000219ab540356cBB839Cbe05303d7705Fa on Base — can you tell me if that's a smart contract or a normal account?"}],"resultDescription":"Returns a JSON object indicating success, the account type classification (contract or EOA), and a payment receipt containing the transaction hash, USD amount charged, and a unique receipt ID. The core result tells you definitively whether the queried address has deployed bytecode (contract) or not (EOA) at the specified block.","failureModes":["Invalid address format (not matching 0x[40 hex chars]) returns a validation error","Unsupported chain value outside the allowed enum returns an error","Querying a future block number may return an error or empty result","Network connectivity issues to the target EVM chain may cause timeouts","Payment failure or insufficient funds results in a 402 response before the query executes"],"whenToPreferThis":"Use this endpoint when you need a quick, pay-per-call classification of an EVM address across 10 supported chains without running your own node. Prefer it over general-purpose RPC calls when you want a simple boolean-style answer with a built-in receipt for auditability. It is especially useful in agent workflows that need to gate logic on whether an address is a contract (e.g. before calling contract-specific methods) or an EOA (e.g. before signing messages).","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-01T18:55:31.389Z","isFirstParty":false,"canonicalSlug":"evm-address-type-checker-contract-vs-eoa-551d085e"}