# Agent Data Tools – Base ETH Balance Lookup

> Agent Data Tools – Base ETH Balance Lookup is a paid API for AI agents from agent-data-tools.revmesh2074.workers.dev, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-28).

Returns the native ETH balance of any wallet or contract address on the Base blockchain, including the block number, balance in ETH and Wei.

## Facts

- Endpoint: GET https://agent-data-tools.revmesh2074.workers.dev/base/balance?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-28
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent-data-tools-base-eth-balance-lookup-c09ff799
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Ms5LOhgcw8y22PvKOu5p4

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 agent-data-tools-base-eth-balance-lookup-c09ff799
```

Example prompt: What's the current ETH balance of the wallet 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 on Base — show me both the human-readable ETH amount and the raw Wei value?

## When to prefer this

Choose this endpoint when you need a quick, no-account, pay-per-call native ETH balance check on the Base network specifically. It is ideal for AI agents that need on-chain balance data without setting up API keys or managing subscriptions. Prefer this over RPC node providers when you want micropayment-based access ($0.001/call in USDC) and don't want to manage node infrastructure. Not suitable for ERC-20 token balances or balances on other chains (use sibling endpoints for Ethereum, Arbitrum, Optimism, Polygon).

## Known failure modes

- Invalid or malformed 0x address returns an error response
- Address not found or zero-balance address returns balance of '0'
- Network congestion on Base may cause slow or timeout responses
- Payment failure via x402 (insufficient USDC) results in no charge and no response
- Rate limiting if many rapid calls are made

## How this service works

Native ETH balance (eth_getBalance) of any 0x wallet address on Base at the latest block, in wei and in ETH. Use to check whether a wallet can pay gas or a transfer; for ERC-20 tokens use base_token_balance, for all holdings at once use wallet_portfolio. A malformed address is rejected with 400, uncharged.

## Output

Returns a JSON object containing: the wallet/contract address queried, the chain name ('Base'), the chain ID (8453), the native token symbol ('ETH'), the balance formatted as a human-readable decimal string, the balance in Wei as a string, and the block number at which the balance was read.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "address"
 ],
 "properties": {
  "address": {
   "type": "string",
   "description": "0x wallet or contract address"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "block": {
   "type": "number"
  },
  "chain": {
   "type": "string"
  },
  "symbol": {
   "type": "string"
  },
  "address": {
   "type": "string"
  },
  "balance": {
   "type": "string"
  },
  "chainId": {
   "type": "number"
  },
  "balanceWei": {
   "type": "string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent-data-tools-base-eth-balance-lookup-c09ff799/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent-data-tools.revmesh2074.workers.dev](https://www.zero.xyz/host/agent-data-tools.revmesh2074.workers.dev/llms.txt)