ToolVet
75trust / 100

Chain Approvals

by Tanod chainpeek in Onchain & crypto

x402 APIPassing, checked 3 h ago

chainpeek (Tanod) live token approvals of a wallet: ERC-20 and Permit2 allowances with risk flags and unsigned revoke transactions, on Base or Ethereum. Use when an agent must list and revoke its wallet's live token approvals, on a schedule or after a risky signature.

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

Last 30 days

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Status and outage history · Atom feed

Uptime
100%
Response time
322 ms typical, 322 ms slowest 5%
Last check
3 h ago
Next check
any minute now

How to call it

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

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.

POST https://tanod.dev/v1/chain/approvals
content-type: application/json

{
  "chain": "base",
  "spenders": [
    "0x8F2E6A1c3B9d7e5F0A4C2b8D6E1f3a9c7B5d0E24"
  ],
  "wallet": "0x5A0b54D5dc17e0AadC383d2db43B0a0D3E029c4c"
}

Parameters

ParameterTypeRequiredDescription
chainstringYesbase or ethereum (the chains with built-in USDC and USDT here). One of: base, ethereum.
lookback_blocksintegerNoLatest blocks scanned for approval events (0-6,000; default 6,000, about 3.3 hours on Base and 20 hours on Ethereum). 0 scans nothing and checks `spenders` and Permit2 only. Default: 6000.
spendersarray of string or nullNoUp to 50 spender addresses whose ERC-20 and Permit2 allowances are read directly on every audited token, however old (tokens x spenders at most 200). The full-coverage path for spenders you know. Default: null.
stale_daysintegerNoAn allowance is stale when the spender pulled nothing from the wallet in this many days (1-3,650; default 90). Default: 90.
tokensarray of string or nullNoUp to 50 token contracts to audit. Default: USDC, USDT and up to 18 tokens the wallet has sent (from its transfer history). Default: null.
walletstringYesThe wallet whose approvals are audited (0x + 40 hex).

Example response

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

Example response, 34 lines
{
  "allowances": [],
  "allowances_total": 3,
  "block": 52512000,
  "block_timestamp": 1760300000,
  "chain": "base",
  "checked": {
    "erc20": 5,
    "live": 3,
    "pairs": 7,
    "permit2": 2
  },
  "history": {
    "blocks": 6000,
    "from_block": 52506001,
    "read": true,
    "to_block": 52512000
  },
  "limits": [
    "The log scan covers only the la…"
  ],
  "reasons": [],
  "risk": "high",
  "rpc_calls": 10,
  "rules": {
    "key_controlled": "the spender has no code, or onl…",
    "live": "ERC-20 allowance > 0, or Permit…",
    "new_contract": "the spender had no code 30 days…",
    "unlimited": "at least 2^255 (Permit2: 2^159)…"
  },
  "stale_days": 90,
  "tokens": [],
  "wallet": "0x5A0b54D5dc17e0AadC383d2db43B0…"
}

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 -X POST 'https://tanod.dev/v1/chain/approvals' \
  -H 'content-type: application/json' \
  --data-raw '{"chain":"base","spenders":["0x8F2E6A1c3B9d7e5F0A4C2b8D6E1f3a9c7B5d0E24"],"wallet":"0x5A0b54D5dc17e0AadC383d2db43B0a0D3E029c4c"}'

# 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/approvals' \
  -H 'content-type: application/json' \
  --data-raw '{"chain":"base","spenders":["0x8F2E6A1c3B9d7e5F0A4C2b8D6E1f3a9c7B5d0E24"],"wallet":"0x5A0b54D5dc17e0AadC383d2db43B0a0D3E029c4c"}' \
  | 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%2Ftanod.dev%2Fv1%2Fchain%2Fapprovals&method=POST
const res = await pay("https://tanod.dev/v1/chain/approvals", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "chain": "base",
    "spenders": [
      "0x8F2E6A1c3B9d7e5F0A4C2b8D6E1f3a9c7B5d0E24"
    ],
    "wallet": "0x5A0b54D5dc17e0AadC383d2db43B0a0D3E029c4c"
  }),
});
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.post(
        "https://tanod.dev/v1/chain/approvals",
        json={
            "chain": "base",
            "spenders": [
                "0x8F2E6A1c3B9d7e5F0A4C2b8D6E1f3a9c7B5d0E24",
            ],
            "wallet": "0x5A0b54D5dc17e0AadC383d2db43B0a0D3E029c4c",
        },
    )
    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
3 h agoPassed402443 ms$0.005
7 h agoPassed402282 ms$0.005
16 h agoPassed402322 ms$0.005