# Cortex Cloud ETH Balance Lookup

> Cortex Cloud ETH Balance Lookup is a paid API for AI agents from api.cortexcloud.org, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-15).

Retrieves the ETH balance of a given Ethereum wallet address on the Ethereum network

## Facts

- Endpoint: GET https://api.cortexcloud.org/x402/v1/data/eth/balance
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/cortex-cloud-eth-balance-lookup-6577a798
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_AkrTLDQZMqz9FkkUwPBYt

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 cortex-cloud-eth-balance-lookup-6577a798
```

Example prompt: What's the current ETH balance for the wallet address 0xAbC123...? Just give me the balance in ETH on Ethereum mainnet.

## When to prefer this

Use this endpoint when an AI agent needs to retrieve an Ethereum wallet's ETH balance on-demand without managing API keys or subscriptions. Ideal for pay-per-call agent workflows using x402/USDC micropayments on Base. Prefer this over RPC node providers when you want zero-setup, per-call billing with no long-term credential management.

## Known failure modes

- Invalid or malformed Ethereum address returns an error response
- Address not found on Ethereum mainnet returns zero balance or error
- Network congestion may cause delayed or stale balance data
- Payment failure via x402/USDC results in 402 Payment Required without returning data
- Rate limiting or service downtime returns 5xx errors

## How this service works

OpenAI-compatible AI and data API for agents. Pay per call in USDC on Base via x402 — no API keys, no subscriptions, no lock-in.

## Output

Returns a JSON object containing the queried wallet address, its current ETH balance as a decimal string, and the network name (e.g. 'ethereum'). Example: {"address":"0x...","balance":"1.234","network":"ethereum"}.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "format": "application/json",
 "example": {
  "address": "0x...",
  "balance": "1.234",
  "network": "ethereum"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/cortex-cloud-eth-balance-lookup-6577a798/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.cortexcloud.org](https://www.zero.xyz/host/api.cortexcloud.org/llms.txt)