ToolVet
78trust / 100

Evm Decode

by SiteCheck in Onchain & crypto

x402 APIPassing, checked 27 min ago

Function signatures for a 4-byte selector, and for calldata the decoded arguments. Signatures come from the openchain.xyz database, with 4byte.directory as fallback. Calldata is decoded against each candidate until one fits the selector and the arguments; bigints are returned as strings. Read-only.

GET
https://api.sitecheck-api.workers.dev/api/evm/decode
Price
$0.002
per call in USDC
Uptime
100%
last 30 days
Response time
57 ms
57 ms slowest 5%
Last check
Passed
27 min ago, next in 4 min

Run a free test callHow to call it

Reliability

All checks passedSome failedAll failedNot checked

Status and outage history · Atom feed

How to call it

GET https://api.sitecheck-api.workers.dev/api/evm/decode

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.

GET https://api.sitecheck-api.workers.dev/api/evm/decode?data=0xa9059cbb000000000000000000000000d8da6bf26964af9d7eed9e03e53415d37aa96045000000000000000000000000000000000000000000000000000000000000000a

Parameters

ParameterTypeRequiredDescription
datastringNoCalldata, 0x followed by hex (at least 4 bytes)
selectorstringNoOr only the selector: 0x followed by 8 hex characters

Example response

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

{
  "checkedAt": "2026-10-14T07:00:20.286Z",
  "decoded": {
    "args": [
      "0xd8dA6BF26964aF9D7eEd9e03E53415D37aA96045",
      "10"
    ],
    "name": "transfer",
    "signature": "transfer(address,uint256)"
  },
  "selector": "0xa9059cbb",
  "signatures": [
    "transfer(address,uint256)"
  ],
  "source": "openchain.xyz signature database, 4byte.directory (fallback)"
}

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 'https://api.sitecheck-api.workers.dev/api/evm/decode?data=0xa9059cbb000000000000000000000000d8da6bf26964af9d7eed9e03e53415d37aa96045000000000000000000000000000000000000000000000000000000000000000a'

# 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.sitecheck-api.workers.dev/api/evm/decode?data=0xa9059cbb000000000000000000000000d8da6bf26964af9d7eed9e03e53415d37aa96045000000000000000000000000000000000000000000000000000000000000000a' \
  | 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%2Fapi.sitecheck-api.workers.dev%2Fapi%2Fevm%2Fdecode
const res = await pay("https://api.sitecheck-api.workers.dev/api/evm/decode?data=0xa9059cbb000000000000000000000000d8da6bf26964af9d7eed9e03e53415d37aa96045000000000000000000000000000000000000000000000000000000000000000a");
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.get("https://api.sitecheck-api.workers.dev/api/evm/decode?data=0xa9059cbb000000000000000000000000d8da6bf26964af9d7eed9e03e53415d37aa96045000000000000000000000000000000000000000000000000000000000000000a")
    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
27 min agoPassed40273 ms$0.002
5 h agoPassed40241 ms$0.002
9 h agoPassed40257 ms$0.002