# Ethereum Mainnet ETH Balance Lookup (eth_getBalance)

> Ethereum Mainnet ETH Balance Lookup (eth_getBalance) is a paid API for AI agents from api.arysphere.com, paid per call via x402, $0.002/call, status down (last checked 2026-10-30).

Returns the native ETH balance (in wei) of a given Ethereum address at the latest block via eth_getBalance JSON-RPC.

## Facts

- Endpoint: POST https://api.arysphere.com/v1/ventures/x402_chain_reads_v1/eth_getbalance?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: down
- Last checked: 2026-10-30
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/ethereum-mainnet-eth-balance-lookup-eth-getbalance-d7b1ecd0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_qUUnsnlF7L35QvHcqDqk4

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 ethereum-mainnet-eth-balance-lookup-eth-getbalance-d7b1ecd0 -d '<json body>'
```

Example prompt: What's the current ETH balance of the wallet 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045? Give me the raw wei amount from Ethereum mainnet.

## When to prefer this

Choose this endpoint when you need a quick, single-address native ETH balance read on Ethereum mainnet with pay-per-call micropayment billing (no API key required, USDC on Base). Prefer it over node providers requiring subscriptions when your agent needs lightweight, on-demand balance checks without managing RPC credentials.

## Known failure modes

- Invalid address format (not 0x + 40 hex) — request rejected or error response
- Address has zero balance — returns 0 wei, not an error
- Network or node timeout — service temporarily unavailable
- Payment failure in USDC on Base — call not executed
- Rate limiting if many rapid successive calls

## Output

A JSON-RPC response containing the ETH balance of the queried address in wei (hexadecimal or decimal string), reflecting the state at the latest Ethereum mainnet block. The agent receives the raw on-chain balance suitable for further conversion or display.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "address": {
       "type": "string",
       "pattern": "^0x[0-9a-fA-F]{40}$",
       "description": "0x + 40 hex"
      }
     }
    }
   },
   "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/ethereum-mainnet-eth-balance-lookup-eth-getbalance-d7b1ecd0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.arysphere.com](https://www.zero.xyz/host/api.arysphere.com/llms.txt)