ToolVet
16trust / 100

Token Allowance

by Vextorium in Onchain & crypto

x402 APIFailing, checked 2 h ago

ERC-20 allowance lookup: how much a spender can move from an owner's balance, flagging unlimited approvals.

POST https://api.vextorium.com/v1/token-allowance

Last 30 days

All checks passedSome failedAll failedNot checked

Status and outage history · Atom feed

Uptime
0.0%
Response time
- typical, - slowest 5%
Last check
2 h ago: Amount "0.003" is not in atomic token units
Next check
any minute now

How to call it

POST https://api.vextorium.com/v1/token-allowance

Each call costs $0.003 in USDC on Base, paid with the request over x402.

Run a free test callOne unpaid request, the way an agent sends it. You see the payment challenge it gets back. Nothing is charged.

Example request

From the listing.

POST https://api.vextorium.com/v1/token-allowance
content-type: application/json

{
  "network": "base",
  "owner": "0xb9f06D2734B7E9D7b21B64C4D8b95bd774b71aCf",
  "spender": "0x3d4e44Eb1374240CE5F1B871ab261CD16335B76a",
  "token": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
}

Parameters

ParameterTypeRequiredDescription
networkstringNoEVM network (default base) One of: base, ethereum, arbitrum, optimism, polygon.
ownerstringYesOwner wallet address
spenderstringYesSpender (contract) address
tokenstringYesToken contract address

Example response

The provider's example. We can't check it without paying.

{
  "contract": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
  "network": "base",
  "note": null,
  "owner": "0xb9f06D2734B7E9D7b21B64C4D8b95bd774b71aCf",
  "permission": 0,
  "spender": "0x3d4e44Eb1374240CE5F1B871ab261CD16335B76a",
  "token": "USDC",
  "unlimited": false
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.003.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://api.vextorium.com/v1/token-allowance' \
  -H 'content-type: application/json' \
  --data-raw '{"network":"base","owner":"0xb9f06D2734B7E9D7b21B64C4D8b95bd774b71aCf","spender":"0x3d4e44Eb1374240CE5F1B871ab261CD16335B76a","token":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"}'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - -X POST 'https://api.vextorium.com/v1/token-allowance' \
  -H 'content-type: application/json' \
  --data-raw '{"network":"base","owner":"0xb9f06D2734B7E9D7b21B64C4D8b95bd774b71aCf","spender":"0x3d4e44Eb1374240CE5F1B871ab261CD16335B76a","token":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"}' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode
JavaScript: pay and call
// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.003 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.003" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.003 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fapi.vextorium.com%2Fv1%2Ftoken-allowance&method=POST
const res = await pay("https://api.vextorium.com/v1/token-allowance", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "network": "base",
    "owner": "0xb9f06D2734B7E9D7b21B64C4D8b95bd774b71aCf",
    "spender": "0x3d4e44Eb1374240CE5F1B871ab261CD16335B76a",
    "token": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
  }),
});
console.log(res.status, await res.text());
Python: pay and call
# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.003 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.003"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.post(
        "https://api.vextorium.com/v1/token-allowance",
        json={
            "network": "base",
            "owner": "0xb9f06D2734B7E9D7b21B64C4D8b95bd774b71aCf",
            "spender": "0x3d4e44Eb1374240CE5F1B871ab261CD16335B76a",
            "token": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
        },
    )
    print(res.status_code, res.text)

Security scan

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

Recent checks

WhenResultHTTPTimePrice
2 h agoAmount "0.003" is not in atomic token units402105 ms$0.003
6 h agoAmount "0.003" is not in atomic token units40289 ms$0.003
11 h agoAmount "0.003" is not in atomic token units40277 ms$0.003
15 h agoAmount "0.003" is not in atomic token units40276 ms$0.003
19 h agoAmount "0.003" is not in atomic token units40297 ms$0.003
24 h agoAmount "0.003" is not in atomic token units402247 ms$0.003
28 h agoAmount "0.003" is not in atomic token units40282 ms$0.003
32 h agoAmount "0.003" is not in atomic token units402180 ms$0.003
36 h agoAmount "0.003" is not in atomic token units40285 ms$0.003
40 h agoAmount "0.003" is not in atomic token units402248 ms$0.003
44 h agoAmount "0.003" is not in atomic token units402103 ms$0.003
2 days agoAmount "0.003" is not in atomic token units40285 ms$0.003
2 days agoAmount "0.003" is not in atomic token units402205 ms$0.003
2 days agoAmount "0.003" is not in atomic token units40278 ms$0.003
3 days agoAmount "0.003" is not in atomic token units40274 ms$0.003