ToolVet
82trust / 100

Token Allowance

by ERC-20 allowance (owner to in Onchain & crypto

x402 APIPassing, checked 4 h ago

How much of an ERC-20 token a spender contract is approved to move from an owner wallet - the approval check an agent runs before a swap, a bridge, or an x402 transferWithAuthorization flow. Returns the allowance as an exact decimal string scaled by the token's decimals, the raw uint256, and an `unlimited` flag for max-uint style approvals.

POST https://agent402.tools/api/token-allowance

Last 30 days

All checks passedSome failedAll failedNot checked
Uptime
100%
Response time
195 ms typical, 195 ms slowest 5%
Last check
4 h ago
Next check
any minute now

How to call it

# See the payment challenge (nothing is charged)
curl -i -X POST "https://agent402.tools/api/token-allowance" \
  -H "content-type: application/json" \
  -d '{"contract":"0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","network":"ethereum","owner":"0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045","spender":"0x3fC91A3afd70395Cd496C647d5a6CC9D4B2b7FAD"}'
import { wrapFetchWithPayment } from "@x402/fetch";
import { x402Client } from "@x402/core/client";
import { ExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

const client = new x402Client().register(
  "eip155:8453",
  new ExactEvmScheme(privateKeyToAccount(process.env.AGENT_KEY)),
);
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? Preflight it first for $0.005:
// GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fagent402.tools%2Fapi%2Ftoken-allowance
const res = await pay("https://agent402.tools/api/token-allowance", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({"contract":"0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48","network":"ethereum","owner":"0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045","spender":"0x3fC91A3afd70395Cd496C647d5a6CC9D4B2b7FAD"}),
});
console.log(await res.json());

Example input

{
  "contract": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
  "network": "ethereum",
  "owner": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045",
  "spender": "0x3fC91A3afd70395Cd496C647d5a6CC9D4B2b7FAD"
}

Example output

{
  "allowance": "0",
  "chainId": 1,
  "contract": "0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48",
  "decimals": 6,
  "fetchedAt": "2026-08-22T12:00:00.000Z",
  "network": "ethereum",
  "owner": "0xd8da6bf26964af9d7eed9e03e53415d37aa96045",
  "raw": "0",
  "source": "alchemy",
  "spender": "0x3fc91a3afd70395cd496c647d5a6cc9d4b2b7fad",
  "symbol": "USDC",
  "unlimited": false
}

Security scan

  • No findings. We scan names, descriptions and tool definitions for hidden instructions and other prompt-injection patterns.

Recent checks

WhenResultHTTPTimePrice
4 h agoPassed402195 ms$0.002