# EVM Token Balance & Allowance Checker

> EVM Token Balance & Allowance Checker is a paid API for AI agents from free-asset-radar-x402.besenok2018.workers.dev, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-20).

Fetches the token balance and ERC-20 spending allowance for an EVM wallet address on a specified network

## Facts

- Endpoint: GET https://free-asset-radar-x402.besenok2018.workers.dev/api/x402/evm-token-balance-allowance?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-20
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/evm-token-balance-allowance-checker-39db5796
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Z3IOAifDhmy5wQcf4VlQS

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 evm-token-balance-allowance-checker-39db5796
```

Example prompt: Check the USDC balance and allowance approved for the Uniswap router on my wallet 0xAbC...123 on Base network.

## When to prefer this

Choose this endpoint when an AI agent needs a lightweight, pay-per-call EVM token balance and allowance lookup without setting up a full RPC node or indexer. Ideal for autonomous agents operating on Base or other EVM chains that need quick pre-transaction checks at minimal cost ($0.003 USDC per call via x402 protocol).

## Known failure modes

- Invalid or malformed wallet address returns an error response
- Unsupported network name causes lookup failure
- Token contract address not found on specified network
- Spender address not provided results in missing allowance data
- Rate limiting or edge node unavailability may cause transient failures

## How this service works

Stable edge-hosted x402 utilities for autonomous agents.

## Output

Returns a JSON object with the token balance (as a decimal string), the network name, and the current ERC-20 allowance approved for the specified spender address.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "required": {
   "type": "string"
  },
  "properties": {
   "type": "string"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "balance": "12.5",
  "network": "base",
  "allowance": "3"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/evm-token-balance-allowance-checker-39db5796/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from free-asset-radar-x402.besenok2018.workers.dev](https://www.zero.xyz/host/free-asset-radar-x402.besenok2018.workers.dev/llms.txt)