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Riley Craig x402 Agent Store — Chain Code Size Checker
x402
Riley Craig x402 Agent Store — Chain Code Size Checker is a paid API for AI agents from x402-agent-store.rileycraig14.workers.dev, paid per call via x402, $0.09/call, status unknown (last checked 2026-09-14).
Checks whether a given blockchain address is a smart contract by inspecting its on-chain bytecode size, across multiple EVM-compatible chains.
Price / call$0.09
Success—
StatusUnknown
How this service works
Is an address a smart contract or a regular wallet (EOA)? Returns whether deployed bytecode exists and its size via eth_getCode, across Base, Ethereum, Optimism, Arbitrum, Polygon, Gnosis. The safety/identity read wallet, payment and trading agents make before interacting with an address. Live public RPC; one paid call at $0.001.
Output
Returns a JSON object with the queried chain name, address, code_size in bytes, and a boolean is_contract field indicating whether the address has deployed bytecode (true = smart contract, false = EOA or empty account).
Example use cases
Validate counterparty before sending funds
“Before I send tokens to 0x9876543210fedcba9876543210fedcba98765432 on Ethereum, can you verify whether it's actually a smart contract or a regular wallet? I want to make sure I'm not sending to an empty account or something unexpected.”
Audit suspicious token contract addresses
“I need to check if 0xabcdefabcdefabcdefabcdefabcdefabcdefabcd on Polygon is really a deployed smart contract or just someone claiming to have a token. Pull the bytecode size and let me know if it's legit.”
Cross-chain address identity verification
“I'm seeing the same address 0x1111111111111111111111111111111111111111 used across multiple chains. Can you tell me which ones actually have this deployed as a contract versus which ones it's just an EOA, starting with Arbitrum and Optimism?”
Technical details
Endpoint
GEThttps://x402-agent-store.rileycraig14.workers.dev/chain/codeWhen to prefer
Use this endpoint when you need to programmatically determine whether a specific EVM address is a smart contract (has deployed bytecode) or an externally owned account (EOA), across chains like Base, Ethereum, Optimism, Arbitrum, Polygon, or Gnosis. Ideal for agents performing on-chain due diligence, validating counterparty addresses, or enriching address metadata. Costs only $0.001 USDC per call with no API key required.
Side effects
- Missing required 'address' query param returns a validation error
- Invalid or malformed address (not 0x hex) may return an error or zero code_size
- Unsupported chain name may fall back to default (Base) or return an error
- Payment failure via x402 returns HTTP 402 before the query is processed
- Address on a chain where it has no deployed code returns is_contract: false with code_size: 0
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Output
Schema · Response
{
"type": "json",
"example": {
"chain": "base",
"address": "0x...",
"code_size": 12873,
"is_contract": true
}
}Tags
x402
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