ToolVet
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Chain Allowance

by Tanod chainpeek in Onchain & crypto

x402 APIPassing, checked 1 h ago

chainpeek (Tanod) allowance read: the ERC-20 allowance an owner gave a spender, with decimals, symbol and an unlimited-approval flag, on Ethereum or Base. Read-only.

POST https://tanod.dev/v1/chain/allowance

Last 30 days

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Status and outage history · Atom feed

Uptime
100%
Response time
273 ms typical, 448 ms slowest 5%
Last check
1 h ago
Next check
any minute now

How to call it

POST https://tanod.dev/v1/chain/allowance

Each call costs $0.002 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://tanod.dev/v1/chain/allowance
content-type: application/json

{
  "chain": "base",
  "owner": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045",
  "spender": "0x000000000022D473030F116dDEE9F6B43aC78BA3",
  "token": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
}

Parameters

ParameterTypeRequiredDescription
chainstringYesChain to read. One of: ethereum, base.
ownerstringYesToken holder address (0x + 40 hex).
spenderstringYesApproved spender address (0x + 40 hex).
tokenstringYesERC-20 contract address (0x + 40 hex).

Example response

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

{
  "allowance": "0",
  "allowance_raw": "0",
  "block": 52290472,
  "chain": "base",
  "decimals": 6,
  "owner": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045",
  "spender": "0x000000000022D473030F116dDEE9F6B43aC78BA3",
  "symbol": "USDC",
  "token": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
  "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 $0.002.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://tanod.dev/v1/chain/allowance' \
  -H 'content-type: application/json' \
  --data-raw '{"chain":"base","owner":"0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045","spender":"0x000000000022D473030F116dDEE9F6B43aC78BA3","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://tanod.dev/v1/chain/allowance' \
  -H 'content-type: application/json' \
  --data-raw '{"chain":"base","owner":"0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045","spender":"0x000000000022D473030F116dDEE9F6B43aC78BA3","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 $0.002 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.002" });
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 $0.002 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Ftanod.dev%2Fv1%2Fchain%2Fallowance&method=POST
const res = await pay("https://tanod.dev/v1/chain/allowance", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "chain": "base",
    "owner": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045",
    "spender": "0x000000000022D473030F116dDEE9F6B43aC78BA3",
    "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 $0.002 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.002"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.post(
        "https://tanod.dev/v1/chain/allowance",
        json={
            "chain": "base",
            "owner": "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045",
            "spender": "0x000000000022D473030F116dDEE9F6B43aC78BA3",
            "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
1 h agoPassed402704 ms$0.002
5 h agoPassed402271 ms$0.002
9 h agoPassed402260 ms$0.002
13 h agoPassed402270 ms$0.002
17 h agoPassed402254 ms$0.002
21 h agoPassed402269 ms$0.002
24 h agoPassed402276 ms$0.002
28 h agoPassed402273 ms$0.002
32 h agoPassed402263 ms$0.002
35 h agoPassed402263 ms$0.002
39 h agoPassed402444 ms$0.002
42 h agoPassed402448 ms$0.002
46 h agoPassed402276 ms$0.002
2 days agoPassed402271 ms$0.002
2 days agoPassed402275 ms$0.002