Optimism contract check

$0.003 per call · failed calls are never charged · no account or API key needed

Check whether a 0x address on Optimism is a smart contract or a plain wallet: bytecode size, and whether it is an EIP-1167 minimal proxy and which implementation it points to. Use before sending funds or approving a spender; for a fuller risk verdict use check_counterparty. A malformed address is rejected with 400, uncharged.

Run it free (25 free calls) Buy credits by card (from $5) Example result (JSON)

Inputs

NameTypeDescription
address (required)string0x address

Request

Over HTTP, with a card key from /credits:

curl -H "Authorization: Bearer adt_…" "https://agent-data-tools.revmesh2074.workers.dev/op/is-contract?address=0x0b2C639c533813f4Aa9D7837CAf62653d097Ff85"

Or one of your 25 free calls, no key:

curl "https://agent-data-tools.revmesh2074.workers.dev/op/is-contract?address=0x0b2C639c533813f4Aa9D7837CAf62653d097Ff85&trial=1"

Without a key, the same URL answers 402 Payment Required with x402 and MPP terms, so an agent with a wallet pays per call in USDC (Base, Polygon, Arbitrum, Monad, World Chain or Tempo) and retries.

Example result

{
  "chain": "Optimism",
  "chainId": 10,
  "address": "0x0b2C639c533813f4Aa9D7837CAf62653d097Ff85",
  "isContract": true,
  "codeBytes": 1855,
  "minimalProxy": false,
  "implementation": null
}

From an AI agent (MCP)

Add the MCP server to Claude, Cursor or any MCP client. This tool is op_is_contract, and the first 25 successful calls are free:

https://agent-data-tools.revmesh2074.workers.dev/mcp

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