Base contract check

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

Check whether a 0x address on Base 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

Name	Type	Description
`address` (required)	string	0x address

Request

Over HTTP, with a card key from /credits:

curl -H "Authorization: Bearer adt_…" "https://agent-data-tools.revmesh2074.workers.dev/base/is-contract?address=0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"

Or one of your 25 free calls, no key:

curl "https://agent-data-tools.revmesh2074.workers.dev/base/is-contract?address=0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913&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": "Base",
  "chainId": 8453,
  "address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
  "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 base_is_contract, and the first 25 successful calls are free:

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

Base contract check

Inputs

Request

Example result

From an AI agent (MCP)

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