# ERC20 Token Balance Lookup

> ERC20 Token Balance Lookup is a paid API for AI agents from flat-rate-llm.kikoribera03.workers.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Returns the raw and formatted token balance for any ERC20 token (USDC, USDT, DAI, etc.) held by a given wallet address on EVM-compatible chains via balanceOf.

## Facts

- Endpoint: POST https://flat-rate-llm.kikoribera03.workers.dev/v1/evm/erc20-balance
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/erc20-token-balance-lookup-fe07c0cb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_JCoJ3A9mXxZBvZ_GKopZb

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 erc20-token-balance-lookup-fe07c0cb -d '<json body>'
```

Example prompt: What's the USDC balance for wallet 0xAbC...123 on Base? I need the formatted amount and the decimals so I can display it correctly.

## When to prefer this

Choose this endpoint when you need a quick, no-auth, pay-per-call ERC20 balance check across major EVM chains (Base, Ethereum, Polygon, Arbitrum, Optimism) and want both the raw balanceOf integer and the formatted decimal amount in one response. Ideal for agents that need to verify holdings before a transaction, display a portfolio balance, or gate logic on token ownership without setting up an RPC connection or API key.

## Known failure modes

- Invalid or non-checksummed wallet address returns a validation error
- Non-existent or non-ERC20 contract address causes eth_call to revert or return zero
- Unsupported chain identifier returns an error listing valid options
- Network congestion or RPC timeout may cause slow or failed responses
- Wallet with zero balance returns raw '0' and amount 0, which is valid but may be misread as an error

## How this service works

60 paid endpoints with no metering, no API key and no account. Each endpoint has one flat price per call, whatever the size of the request: LLM completions with automatic failover across several large models, read-only EVM tooling over Base, Ethereum, Polygon, Arbitrum and Optimism, and pure crypto utilities that touch no network.

## Output

Returns a JSON object with four fields: 'raw' (the integer balance as a string, straight from balanceOf), 'amount' (the decimal-adjusted human-readable number), 'symbol' (the token ticker, e.g. USDC), and 'decimals' (the token's decimal places, e.g. 6 for USDC). Together these let an agent display or compute with the balance without further on-chain calls.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "token",
  "address"
 ],
 "properties": {
  "chain": {
   "type": "string",
   "description": "base | ethereum | polygon | arbitrum | optimism."
  },
  "token": {
   "type": "string",
   "description": "ERC20 contract address."
  },
  "address": {
   "type": "string",
   "description": "Wallet to look up."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "raw": {
   "type": "string"
  },
  "amount": {
   "type": "number"
  },
  "symbol": {
   "type": "string"
  },
  "decimals": {
   "type": "number"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/erc20-token-balance-lookup-fe07c0cb/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from flat-rate-llm.kikoribera03.workers.dev](https://www.zero.xyz/host/flat-rate-llm.kikoribera03.workers.dev/llms.txt)