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Addresscheck — Base Address Verification
x402
Addresscheck — Base Address Verification is a paid API for AI agents from oraclepost.higgsfield.app, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-17).
Checks whether an Ethereum Base network address is a contract or EOA wallet, and returns its activity status including ETH/USDC balance and transaction count at the latest block.
Price / call$0.001
Success—
StatusUnknown
How this service works
Is this Base address a contract or a wallet, and is it active? Live read: code size (contract vs EOA), transaction count (nonce), ETH and USDC balance, at the latest block. Pass ?address=0x... . Useful before paying an unknown payTo. No third-party API, no cache.
Output
Returns whether the address is a smart contract or EOA (based on code size), its nonce/transaction count, current ETH balance, current USDC balance, and the block number at which data was read — all fetched live from the Base chain with no caching.
Example use cases
Pre-payment recipient validation
“I'm about to send USDC to 0x4e68Ccd3E89f51C3074ca5072bbAC773960dFa36 on Base — can you check if that address is a real wallet or a contract, and whether it's ever had any transactions?”
Smart contract deployment check
“Can you tell me if 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 on Base is a deployed smart contract or just a regular EOA wallet?”
Unknown counterparty due diligence
“Someone just sent me a payment address 0x1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b and I want to know if it's legitimate — is it a contract or a wallet, how much ETH and USDC does it hold, and does it have any transaction history on Base?”
Technical details
Endpoint
GEThttps://oraclepost.higgsfield.app/api/verifyWhen to prefer
Use this endpoint when you need real-time, uncached verification of a Base network address before executing a payment or interaction — specifically when you want to distinguish contracts from wallets AND check activity/balance in a single call. Prefer over generic balance checkers when recipient type (contract vs EOA) matters for safety or routing logic.
Side effects
- Invalid or missing address parameter returns an error
- Non-0x-prefixed address fails validation
- Addresses not on Base network may return zero values or errors
- Network RPC node unavailability causes request failure
- Checksum-invalid addresses may be rejected
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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