# Base Chain Wallet Balance Lookup

> Base Chain Wallet Balance Lookup is a paid API for AI agents from lin-desk-x402.lindesk.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-11).

Returns the ETH and USDC balance of any Ethereum address on Base mainnet, including block number and contract detection.

## Facts

- Endpoint: GET https://lin-desk-x402.lindesk.workers.dev/v1/base/balance?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-11
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-chain-wallet-balance-lookup-fb0afa7f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_YmpAobIVTMFW2vTKNkKuf

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability base-chain-wallet-balance-lookup-fb0afa7f
```

Example prompt: Can you check how much ETH and USDC the wallet 0x4b8ad7ffc8cd960f696059041132339386c28831 holds right now on Base mainnet, and tell me if it's a contract or a regular wallet?

## When to prefer this

Use this endpoint when you need a lightweight, pay-per-call on-chain balance check for any Base mainnet address without requiring API key registration. It is ideal for AI agents that need to verify wallet balances programmatically and pay micro-amounts per lookup via x402/USDC. Prefer it over full blockchain indexers when you only need current ETH and USDC balances for a single address and want minimal setup overhead.

## Known failure modes

- Invalid address format (not matching 0x + 40 hex chars) returns a validation error
- Address not found or zero-balance wallets return balances of 0 rather than an error
- Network congestion on Base may cause increased latency
- Payment failure via x402 prevents the request from being processed
- RPC node downtime may cause lookup failures

## How this service works

Pay-per-call API for AI agents: turn any public web page or PDF into clean, LLM-ready Markdown. $0.002 per call in USDC on Base via x402. No API key, no signup.

## Output

A JSON object containing the wallet's ETH balance (human-readable and in wei), USDC balance (human-readable and raw), the block number and timestamp of the reading, whether the address is a contract, the chain ID (8453 for Base), and a disclaimer that the data is read-only and not financial advice.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "address"
     ],
     "properties": {
      "address": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{40}$",
       "description": "EOA or contract address on Base mainnet"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "eth": {
       "type": "string"
      },
      "usdc": {
       "type": "string"
      },
      "as_of": {
       "type": "integer"
      },
      "address": {
       "type": "string"
      },
      "eth_wei": {
       "type": "string"
      },
      "usdc_raw": {
       "type": "string"
      },
      "disclaimer": {
       "type": "string"
      },
      "is_contract": {
       "type": "boolean"
      },
      "block_number": {
       "type": "integer"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "eth": "1",
  "usdc": "0",
  "as_of": 1791100000,
  "chain": "base",
  "cached": false,
  "address": "0x4200000000000000000000000000000000000006",
  "eth_wei": "1000000000000000000",
  "chain_id": 8453,
  "usdc_raw": "0",
  "disclaimer": "Read-only on-chain data; not financial advice.",
  "elapsed_ms": 45,
  "is_contract": true,
  "block_number": 52120000,
  "usdc_contract": "0x833589fcd6edb6e08f4c7c32d4f71b54bda02913"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-chain-wallet-balance-lookup-fb0afa7f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from lin-desk-x402.lindesk.workers.dev](https://www.zero.xyz/host/lin-desk-x402.lindesk.workers.dev/llms.txt)