# Native ETH Balance on Base

> Native ETH Balance on Base is a paid API for AI agents from x402-echo-service.onrender.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Returns the native ETH balance of a given wallet address on the Base blockchain, in both wei and ether, read directly from a node.

## Facts

- Endpoint: POST https://x402-echo-service.onrender.com/chain/eth-balance
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/native-eth-balance-on-base-4d774b8e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_C8TfOdTjd6vE82DkHYSOT

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 native-eth-balance-on-base-4d774b8e -d '<json body>'
```

Example prompt: What's the current ETH balance of the wallet 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 on Base? Give me both the raw wei amount and the ether equivalent.

## When to prefer this

Choose this endpoint when you need a real-time, live chain read of a wallet's native ETH balance on Base with no API key required and no risk of indexer lag. Prefer it over block explorer APIs when freshness is critical, or when you want a simple one-field POST without authentication overhead.

## Known failure modes

- Invalid or malformed Ethereum address returns an error response
- Address not found on Base (zero balance returned, not an error)
- Node connectivity issues may cause timeouts or 5xx errors
- Payment failure (402) if USDC payment is not attached or insufficient

## How this service works

Read the native ETH balance of an address on Base. POST {"address":"0x..."} and receive the balance in wei and in ether. Live chain state read directly from a node, with no indexer lag and no API key.

## Output

Returns a JSON object containing the queried address's native ETH balance expressed as a raw integer in wei and as a human-readable decimal in ether, reflecting live on-chain state with no indexer lag.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "address": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/native-eth-balance-on-base-4d774b8e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-echo-service.onrender.com](https://www.zero.xyz/host/x402-echo-service.onrender.com/llms.txt)