# Joe EVM RPC – ERC-20 Token Balance

> Joe EVM RPC – ERC-20 Token Balance is a paid API for AI agents from joe-evm-rpc.marnick-yezo.workers.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-13).

Fetches the ERC-20 token balance for a given wallet address and token contract on Base or Ethereum.

## Facts

- Endpoint: GET https://joe-evm-rpc.marnick-yezo.workers.dev/api/chain/erc20-balance
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/joe-evm-rpc-erc-20-token-balance-a07a9db8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap__vL6DaApdwwP0rtm6qVjP

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 joe-evm-rpc-erc-20-token-balance-a07a9db8
```

Example prompt: What's the USDC balance of wallet 0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045 on Base? The USDC contract is 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913.

## When to prefer this

Choose this endpoint when you need a quick, pay-per-call ERC-20 token balance lookup on Base or Ethereum without managing your own RPC infrastructure or API keys. It is ideal for AI agents that need programmatic, low-latency access to on-chain token balances with micropayment billing via x402/USDC. Prefer it over raw RPC calls when you want a structured JSON response with token metadata (name, symbol, decimals) already resolved.

## Known failure modes

- Invalid wallet address format (not a valid 0x hex address) returns a validation error
- Invalid or non-ERC-20 contract address returns zero or error
- Network not supported beyond 'base' and 'ethereum' returns a 422/400 error
- Payment not included or insufficient USDC causes a 402 Payment Required response
- RPC node downtime or latency causes timeout or 5xx error
- Token contract exists but wallet has zero balance — returns 0 (not an error)

## How this service works

Live Base and Ethereum RPC for AI agents: block tip, balances, transactions, and ENS. $0.001 USDC per call on Base.

## Output

Returns a JSON object with the token name, symbol, wallet address, raw balance (as a string), decimal precision, and contract address, plus metadata including the RPC URL used, network, endpoint path, cost in USDC, and a unique request ID.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "headers": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    },
    "pathParams": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    },
    "queryParams": {
     "type": "object",
     "required": [
      "account",
      "token"
     ],
     "properties": {
      "token": {
       "type": "string",
       "pattern": "^0x[a-fA-F0-9]{40}$",
       "description": "ERC-20 contract (alias: contract)"
      },
      "account": {
       "type": "string",
       "pattern": "^0x[a-fA-F0-9]{40}$",
       "description": "Wallet address (alias: address)"
      },
      "network": {
       "enum": [
        "base",
        "ethereum"
       ],
       "type": "string",
       "default": "base",
       "description": "EVM network. Default base."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "data": {
   "name": "USD Coin",
   "symbol": "USDC",
   "account": "0x0000000000000000000000000000000000000000",
   "balance": "0",
   "decimals": 6,
   "contract_address": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
  },
  "meta": {
   "rpc": "https://mainnet.base.org",
   "network": "base",
   "endpoint": "/api/chain/erc20-balance",
   "cost_usdc": "0.001",
   "request_id": "00000000abcdef01"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/joe-evm-rpc-erc-20-token-balance-a07a9db8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from joe-evm-rpc.marnick-yezo.workers.dev](https://www.zero.xyz/host/joe-evm-rpc.marnick-yezo.workers.dev/llms.txt)