API · x402

Balances of one address on Base mainnet in a single call: native ETH, the well-known to…

by QuickBuild agent APIs (incl. LaunchCheck) · verified provider · updated 2026-10-23

30d calls—

30d payers—

MethodHTTP

Outputjson

What it does

Balances of one address on Base mainnet in a single call: native ETH, the well-known tokens USDC, USDT, USDbC, DAI, WETH, cbETH, wstETH, AERO (non-zero only, or all with includeZero=true), plus up to 10 extra ERC-20 contracts you pass in `tokens` (symbol/name/decimals read on-chain). Also nonce, account type (EOA, EIP-7702 delegated EOA, or contract) and a USD total for ETH/WETH (Chainlink) and stablecoins. Read live from public Base RPC via Multicall3; cached 10 s. All params optional: defaults to a well-known public address. Invalid input = 400, never charged.

Tags: base · wallet · balance · crypto · usdc

Call contract

Method: HTTP
Input: HTTP request
Output: json

No input exampleProvider did not publish one in Bazaar metadata.

No output exampleProvider did not publish one in Bazaar metadata.

Use with an agent

Discover. Agents find this listing with GET https://bazaar.saylorinnovations.com/discovery/search?query=…, the MCP tool search_resources, or /discovery/resources.
Inspect. Fetch /resources/69283.json for the price and payment options.
Pay. Call GET https://quickbuild.quynguyenbac.workers.dev/api/base/wallet. The provider answers 402 with its payment requirements. An x402 client signs one of the options below and retries with PAYMENT-SIGNATURE.
Execute. The provider returns 200 with the data. Agent Bazaar is not in the request path and never sees your payment.

For humans

You don't need an account or an API key; you need a wallet holding a small amount of USDC on Base, and an x402-capable client (see the examples below). Call the endpoint unpaid first to see exactly what it asks for.

Pricing & payment

Price: $0.002 / request
Protocol: x402 v2
Auth: No account or API key. Pay per request.
Networks: Base

x402 payment requirements

Scheme	Network	Asset	Amount	Pay to	Timeout
exact	Base eip155:8453	USDC	$0.002	0x751a4c3841bE287544C371B4EE09Bd3366AeA7cf	300s

accepts[] (raw JSON)

[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x751a4c3841bE287544C371B4EE09Bd3366AeA7cf",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "2000",
    "amountUsd": 0.002,
    "maxTimeoutSeconds": 300
  }
]

Examples

curl

curl -X GET 'https://quickbuild.quynguyenbac.workers.dev/api/base/wallet'
# -> 402 Payment Required; read PAYMENT-REQUIRED
# retry the identical request with PAYMENT-SIGNATURE

JavaScript

const res = await fetch("https://quickbuild.quynguyenbac.workers.dev/api/base/wallet", {
  "method": "GET"
});
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}

Python

import httpx
res = httpx.request("GET", "https://quickbuild.quynguyenbac.workers.dev/api/base/wallet")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header

Details

Provider: QuickBuild agent APIs (incl. LaunchCheck)
Endpoint: https://quickbuild.quynguyenbac.workers.dev/api/base/wallet
Machine-readable: /resources/69283.json