Base NFT balance

$0.01 per call · failed calls are never charged · no account or API key needed

How many NFTs of one ERC-721 collection a wallet holds on Base (balanceOf), with the collection's name and symbol. Use to check a holder before a token-gated action or to see whether a wallet still holds a collection; for who holds one token id use base_nft_owner. Both inputs are 0x addresses; a missing contract is 404, a contract that is not ERC-721 422, both uncharged.

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

Try it with your own inputs

0x ERC-721 collection contract address
0x wallet address

Uses one of your 25 free calls. Nothing is charged, and a call that fails is not counted.

Inputs

NameTypeDescription
contract (required)string0x ERC-721 collection contract address
address (required)string0x wallet address

Request

Over HTTP, with a card key from /credits:

curl -H "Authorization: Bearer adt_…" "https://agent-data-tools.revmesh2074.workers.dev/base/nft-balance?contract=0x03a520b32C04BF3bEEf7BEb72E919cf822Ed34f1&address=0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045"

Or one of your 25 free calls, no key:

curl "https://agent-data-tools.revmesh2074.workers.dev/base/nft-balance?contract=0x03a520b32C04BF3bEEf7BEb72E919cf822Ed34f1&address=0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045&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 or Solana over x402; Base or Tempo over MPP) and retries.

Example result

{
  "chain": "Base",
  "chainId": 8453,
  "contract": "0x03a520b32C04BF3bEEf7BEb72E919cf822Ed34f1",
  "address": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045",
  "balance": "2",
  "name": "Uniswap V3 Positions NFT-V1",
  "symbol": "UNI-V3-POS"
}

From an AI agent (MCP)

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

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

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