ToolVet
78trust / 100

Chain Allowance

by api.x-402.online in Onchain & crypto

x402 APIPassing, checked 24 min ago

Get an ERC-20 allowance with the owner's balance and a sufficiency verdict for the amount you plan to pull. ERC-20 allowance of a spender on an owner (USDC by default), with the owner's balance and, if you pass ?amount=, a verdict: i…

GET
https://api.x-402.online/v1/chain/allowance
Price
$0.005
per call in USDC
Uptime
100%
last 30 days
Response time
310 ms
2.6 s slowest 5%
Last check
Passed
24 min ago, next in 7 min

Run a free test callHow to call it

Reliability

All checks passedSome failedAll failedNot checked

Status and outage history · Atom feed · Watch with other listings

How to call it

GET https://api.x-402.online/v1/chain/allowance

Each call costs $0.005 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.

GET https://api.x-402.online/v1/chain/allowance?amount=5&owner=0x2c871C2b8876dc35e9E19646FDa5ABF1cd27735F&spender=0x68214ff5c44f38d19ed886e8d59aadb8cab2ce22

Example response

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

{
  "allowance": {
    "amount": "100",
    "unlimited": false
  },
  "owner_balance": {
    "amount": "19.75"
  },
  "symbol": "USDC",
  "verdict": {
    "allowance_sufficient": true,
    "balance_sufficient": true
  }
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.005.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://api.x-402.online/v1/chain/allowance?amount=5&owner=0x2c871C2b8876dc35e9E19646FDa5ABF1cd27735F&spender=0x68214ff5c44f38d19ed886e8d59aadb8cab2ce22'

# 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 - 'https://api.x-402.online/v1/chain/allowance?amount=5&owner=0x2c871C2b8876dc35e9E19646FDa5ABF1cd27735F&spender=0x68214ff5c44f38d19ed886e8d59aadb8cab2ce22' \
  | 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 $0.005 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.005" });
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 $0.005 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fapi.x-402.online%2Fv1%2Fchain%2Fallowance
const res = await pay("https://api.x-402.online/v1/chain/allowance?amount=5&owner=0x2c871C2b8876dc35e9E19646FDa5ABF1cd27735F&spender=0x68214ff5c44f38d19ed886e8d59aadb8cab2ce22");
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 $0.005 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.005"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://api.x-402.online/v1/chain/allowance?amount=5&owner=0x2c871C2b8876dc35e9E19646FDa5ABF1cd27735F&spender=0x68214ff5c44f38d19ed886e8d59aadb8cab2ce22")
    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
24 min agoPassed402299 ms$0.005
5 h agoPassed402282 ms$0.005
9 h agoPassed402340 ms$0.005
13 h agoPassed402277 ms$0.005
18 h agoPassed402531 ms$0.005
Show 10 older checks
22 h agoPassed402422 ms$0.005
26 h agoPassed402322 ms$0.005
30 h agoPassed402295 ms$0.005
35 h agoPassed402453 ms$0.005
39 h agoPassed402460 ms$0.005
43 h agoPassed402386 ms$0.005
47 h agoPassed402344 ms$0.005
2 days agoPassed402272 ms$0.005
2 days agoPassed402356 ms$0.005
2 days agoPassed402305 ms$0.005