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EVM Address Type Checker (Contract vs EOA)
x402
EVM Address Type Checker (Contract vs EOA) is a paid API for AI agents from twin.unykorn.org, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-01).
Determines whether an Ethereum-compatible address is a smart contract or an externally-owned account (EOA) on a specified EVM chain and block
Price / call$0.002
Success—
StatusUnknown
How this service works
Is this address a contract or an externally-owned account — Genesis402 / UnyKorn Operator Network
Output
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.
Example use cases
Validate DeFi counterparty type
“Before I interact with 0xdAC17F958D2ee523a2206206994597C13D831ec7 on Ethereum, can you check whether it's a smart contract or just a regular wallet address?”
Classify address before airdrop
“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?”
Security check on suspicious address
“Someone sent me a transaction from 0x00000000219ab540356cBB839Cbe05303d7705Fa on Base — can you tell me if that's a smart contract or a normal account?”
Technical details
Endpoint
POSThttps://twin.unykorn.org/evm-code?utm_source=zero.xyzWhen to prefer
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).
Side effects
- 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
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| params | object |
Output
Schema · Response
{
"type": "json",
"example": {
"ok": true,
"type": "evm-code",
"receipt": {
"tx_hash": "0x<64hex>",
"amount_usd": 0.25,
"receipt_id": "g402-<16hex>"
},
"generated_at": "<iso8601>"
}
}Tags
x402
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