# Multichain RPC – ERC-20 Token Balance Lookup

> Multichain RPC – ERC-20 Token Balance Lookup is a paid API for AI agents from multichain-rpc.clankerceo.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-14).

Returns the ERC-20 token balance for a given wallet address on Base, Polygon, Arbitrum, Optimism, or Ethereum.

## Facts

- Endpoint: GET https://multichain-rpc.clankerceo.workers.dev/erc20-balance
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/multichain-rpc-erc-20-token-balance-lookup-b7695e7d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_ZjfW_zPbD_ChvAFXatSEY

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 multichain-rpc-erc-20-token-balance-lookup-b7695e7d
```

Example prompt: What's the USDC balance for wallet 0xAbC123...def on Base right now?

## When to prefer this

Choose this endpoint when you need a quick, cheap per-call ERC-20 token balance lookup across the five most popular EVM chains (Base, Polygon, Arbitrum, Optimism, Ethereum) without provisioning your own RPC infrastructure. At $0.002 USDC per call it is well-suited for agents that need frequent, lightweight balance checks without a long-term API subscription. Prefer it over native ETH balance endpoints when the target asset is an ERC-20 token.

## Known failure modes

- Invalid or malformed wallet address returns an error or empty result
- Unsupported chain name returns an error — only Base, Polygon, Arbitrum, Optimism, Ethereum are supported
- Missing required query parameters (chain or address) results in a 400-level error
- Underlying RPC node unavailable may return a 5xx or timeout
- Payment not included or insufficient USDC causes a 402 Payment Required response

## How this service works

Cheap, factual EVM chain lookups priced per call in USDC. Base, Polygon, Arbitrum, Optimism and Ethereum.

## Output

Returns a JSON object containing the chain name, the queried wallet address, and the native or ERC-20 token balance expressed in both raw wei and human-readable decimal form along with the token symbol.

## 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",
    "queryParams"
   ],
   "properties": {
    "type": {
     "enum": [
      "http"
     ],
     "type": "string"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "chain": {
       "type": "string"
      },
      "address": {
       "type": "string"
      }
     }
    }
   }
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "enum": [
      "json"
     ],
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "chain": "base",
  "native": {
   "wei": "1000000",
   "amount": "0.000001",
   "symbol": "ETH"
  },
  "address": "0x…"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/multichain-rpc-erc-20-token-balance-lookup-b7695e7d/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from multichain-rpc.clankerceo.workers.dev](https://www.zero.xyz/host/multichain-rpc.clankerceo.workers.dev/llms.txt)