Base wallet balance API: ETH, USDC and token holdings with nonce

$0.005 per call · failed calls are never charged · no account or subscription: pay per call with a card key or USDC

Base only (all 5 chains: wallet_balances; USD values: wallet_portfolio). An address on Base: ETH and major token balances (USDC, WETH, cbBTC, DAI, USDbC, cbETH, AERO, EURC) plus up to 20 token addresses you pass, the account nonce, and whether it is an EOA, a contract or an EIP-7702 account. The nonce counts outgoing transactions only; not transfer or trading history. Use to check a counterparty's holdings.

When to use it

Run it free (25 free calls) Buy credits by card (from $1) Example result (JSON)

Try it with your own inputs

Wallet or contract address on Base (0x...)

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

Inputs

NameTypeDescription
address (required)stringWallet or contract address on Base (0x...)
tokensstringOptional comma-separated extra ERC-20 addresses to check (max 20)

Request

Over HTTP, with a card key from /credits:

curl -H "Authorization: Bearer adt_…" "https://tools.funwords.eu/wallet?address=0x4200000000000000000000000000000000000006"

Or one of your 25 free calls, no key:

curl "https://tools.funwords.eu/wallet?address=0x4200000000000000000000000000000000000006&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",
  "address": "0x4200000000000000000000000000000000000006",
  "type": "contract",
  "eth": {
    "wei": "286016330790748434767802",
    "formatted": "286016.330790748434767802"
  },
  "accountNonce": 0,
  "limitations": [
    "accountNonce is the Base EVM account nonce; for EOAs it reflects outgoing transactions only, not full transaction, token-transfer, or trading history."
  ],
  "tokens": [
    {
      "address": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913",
      "symbol": "USDC",
      "decimals": 6,
      "balance": "167551481",
      "balanceFormatted": "167.551481"
    }
  ]
}

From an AI agent (MCP)

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

https://tools.funwords.eu/mcp

Questions

Which chains?

Base only. For all five chains use /wallet/balances; for USD values use /wallet/portfolio.

Is the nonce a transaction history?

No. It counts outgoing transactions only, not transfers or trading history.

How do I pay?

Each successful call costs $0.005; failed calls are not charged. The first 25 calls are free. Then pay with card credits (from $1; the key goes in an Authorization header or, for clients that can only fetch a URL, as api_key= in the URL) or per call in USDC over x402 or MPP. No account is needed.

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