# Riley Craig x402 Agent Store — On-Chain Balance Lookup

> Riley Craig x402 Agent Store — On-Chain Balance Lookup is a paid API for AI agents from x402-agent-store.rileycraig14.workers.dev, paid per call via x402, $0.003/call, status unknown (last checked 2026-09-14).

Returns the native token balance, transaction count, and USD value for a given wallet address on a specified EVM chain, paid per-call via x402/USDC.

## Facts

- Endpoint: GET https://x402-agent-store.rileycraig14.workers.dev/chain/balance
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/riley-craig-x402-agent-store-on-chain-balance-lookup-6a4acf36
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_nG3Uuj6FtEDa9UAkEusxb

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 riley-craig-x402-agent-store-on-chain-balance-lookup-6a4acf36
```

Example prompt: What's the current ETH balance and USD value of wallet 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 on Base — and how many transactions have they made?

## When to prefer this

Use this endpoint when an AI agent needs to read the native token balance (ETH, MATIC, etc.) of any EVM-compatible wallet address without setting up API keys or subscriptions — ideal for on-demand, pay-per-call blockchain reads in agentic workflows using x402 micropayments on Base.

## Known failure modes

- Invalid or malformed wallet address returns an error response
- Unsupported chain name returns an error or default to base
- Payment failure via x402 protocol results in 402 status with no data returned
- Network or RPC issues for the requested chain may cause a timeout or 503
- Address with no activity returns zero balance and zero tx_count

## How this service works

The cheapest on-chain RPC read: any address's native coin balance (ETH/POL/xDAI) with live USD value and outgoing transaction count (nonce), across Base, Ethereum, Optimism, Arbitrum, Polygon, Gnosis. The high-frequency balance check wallet-tracking, settlement, and trading agents poll constantly. Free upstream (Blockscout); undercuts onesource.

## Output

A JSON object containing the chain name, native token symbol, wallet address, native token balance as a decimal number, total transaction count, and current USD value of the balance. Example: {chain:'base', symbol:'ETH', address:'0x...', balance:61.6, tx_count:1842, usd_value:99826.71}.

## 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": {
      "chain": {
       "type": "string",
       "description": "base|ethereum|optimism|arbitrum|polygon|gnosis (default base)"
      },
      "address": {
       "type": "string",
       "description": "Account address (0x...)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "balance": {
       "type": "number"
      },
      "tx_count": {
       "type": "number"
      },
      "usd_value": {
       "type": "number"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "chain": "base",
  "symbol": "ETH",
  "address": "0x...",
  "balance": 61.6,
  "tx_count": 1842,
  "usd_value": 99826.71
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/riley-craig-x402-agent-store-on-chain-balance-lookup-6a4acf36/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-agent-store.rileycraig14.workers.dev](https://www.zero.xyz/host/x402-agent-store.rileycraig14.workers.dev/llms.txt)