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Base Mainnet Contract Code Check
x402
Base Mainnet Contract Code Check is a paid API for AI agents from x402.agentindex.world, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-10).
Checks whether a Base mainnet address is a smart contract by retrieving its bytecode size via eth_getCode — returns zero for externally-owned accounts (EOAs).
Price / call$0.003
Success—
StatusUnknown
How this service works
Check whether a Base mainnet address is a contract via eth_getCode - returns bytecode size, zero for an externally-owned account.
Output
Returns the bytecode size (in bytes) for the given Base mainnet address — a non-zero value indicates a deployed smart contract, while zero indicates a plain externally-owned account (EOA) with no code.
Example use cases
Verify token contract before swap
“Before I swap into this Base token at 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913, can you confirm it's actually a deployed smart contract and not just a random wallet address?”
Detect EOA in airdrop recipient list
“I have a recipient address 0x4200000000000000000000000000000000000006 on Base — check whether it's a smart contract or a plain externally-owned account before we include it in the airdrop.”
Due diligence on unknown Base address
“Someone sent me a Base address 0x3fC91A3afd70395Cd496C647d5a6CC9D4B2b7FAD and claimed it's a DEX router contract — can you verify it actually has bytecode deployed on Base mainnet?”
Technical details
Endpoint
GEThttps://x402.agentindex.world/base/code?utm_source=zero.xyzWhen to prefer
Use this endpoint when you need a lightweight, single-call check to determine if a Base mainnet address is a smart contract versus a regular wallet, without needing full ABI decoding or contract interaction. It is faster and cheaper than fetching full transaction history and is ideal for pre-flight validation before token swaps, airdrops, or contract interactions on Base L2.
Side effects
- Invalid or malformed Ethereum address returns an error
- Address not found on Base mainnet returns zero (indistinguishable from EOA at undeployed address)
- Network or RPC node errors may cause timeouts
- Payment failure via x402 protocol blocks the call
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| address | string |
Tags
x402
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