# Base Mainnet ETH & USDC Dual Balance Lookup

> Base Mainnet ETH & USDC Dual Balance Lookup is a paid API for AI agents from biosfera.46-62-215-147.sslip.io, paid per call via x402, $0.002/call, status down (last checked 2026-10-02).

Returns the live native ETH balance and USDC balance of any EVM address on Base mainnet (chain 8453) in a single call, with exact integer units, human-readable decimals, and the block number at which the data was read.

## Facts

- Endpoint: GET https://biosfera.46-62-215-147.sslip.io/o/base-balance?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: down
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/base-mainnet-eth-usdc-dual-balance-lookup-083e0a20
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_6-dbxpnvrz2_DkReCWgW2

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-mainnet-eth-usdc-dual-balance-lookup-083e0a20
```

Example prompt: What are the current ETH and USDC balances for the address 0xAbCd1234...5678 on Base mainnet?

## When to prefer this

Choose this endpoint when you need both the native ETH balance AND the USDC balance of a Base mainnet address in a single, low-latency call rather than making two separate ERC20 balance queries. It is ideal for agents that need a quick dual-asset snapshot on Base (chain 8453) without writing custom multi-call logic. Prefer sibling endpoints for other chains (Ethereum, Arbitrum, Optimism, Polygon) or for arbitrary ERC20 tokens beyond USDC.

## Known failure modes

- Invalid address format (not a 0x-prefixed 40-hex-character string) returns a validation error
- Address not found on Base mainnet returns zero balances rather than an error
- RPC node temporarily unavailable may return a timeout or 5xx error
- Missing required `address` query parameter returns a 400-level error
- Stale block data if the upstream RPC is lagging behind the chain tip

## How this service works

Use when you need the live native ETH balance and USDC balance of any address on Base mainnet (chain 8453) in one call. Returns exact integer units and human decimals, plus the block it was read at. Read-only, public blockchain data.

## Output

Returns the native ETH balance and USDC balance of the queried address on Base mainnet, each expressed as an exact raw integer (in wei / smallest token unit) and a human-readable decimal, along with the block number at which the on-chain state was read.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "address"
     ],
     "properties": {
      "address": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{40}$",
       "description": "EVM address on Base"
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/base-mainnet-eth-usdc-dual-balance-lookup-083e0a20/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from biosfera.46-62-215-147.sslip.io](https://www.zero.xyz/host/biosfera.46-62-215-147.sslip.io/llms.txt)