ToolVet
78trust / 100

Evm Simulate

by SiteCheck in Onchain & crypto

x402 APIPassing, checked 55 min ago

Simulates an EVM transaction execution without broadcasting: { chain, from, to, data, value }. Returns eth_call output, gas estimate, success/revert status with decoded revert reason (Error(string), Panic(uint256)), and token balance if to is an ERC-20. State overrides not supported by public RPCs. Information only, not financial advice.

POST
https://api.sitecheck-api.workers.dev/api/evm/simulate
Price
$0.003
per call in USDC
Uptime
100%
last 30 days
Response time
36 ms
41 ms slowest 5%
Last check
Passed
55 min ago, next any minute now

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

POST https://api.sitecheck-api.workers.dev/api/evm/simulate

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.sitecheck-api.workers.dev/api/evm/simulate
content-type: application/json

{
  "chain": "ethereum",
  "data": "0x70a082310000000000000000000000000000000000000000000000000000000000000000",
  "from": "0x0000000000000000000000000000000000000000",
  "to": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48"
}

Parameters

ParameterTypeRequiredDescription
chainstringYesTarget EVM chain name (e.g. ethereum, base, arbitrum)
datastringNoTransaction calldata in 0x hex format
fromstringNoSender 42-character 0x hex address
tostringYesTarget contract 42-character 0x hex address
valuestringNoOptional value in wei (hex or decimal string)

Example response

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

{
  "chain": "ethereum",
  "checkedAt": "2026-10-15T18:26:14.365Z",
  "disclaimer": "Information only, not financial advice.",
  "from": "0x0000000000000000000000000000000000000000",
  "gasEstimate": 31383,
  "provider": "ethereum-rpc.publicnode.com",
  "returnData": "0x0000000000000000000000000000000000000000000000000000000000000000",
  "revertReason": null,
  "source": "Public EVM RPC (Ethereum Mainnet)",
  "stateOverridesSupported": false,
  "success": true,
  "to": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
  "token": null
}

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.sitecheck-api.workers.dev/api/evm/simulate' \
  -H 'content-type: application/json' \
  --data-raw '{"chain":"ethereum","data":"0x70a082310000000000000000000000000000000000000000000000000000000000000000","from":"0x0000000000000000000000000000000000000000","to":"0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48"}'

# 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.sitecheck-api.workers.dev/api/evm/simulate' \
  -H 'content-type: application/json' \
  --data-raw '{"chain":"ethereum","data":"0x70a082310000000000000000000000000000000000000000000000000000000000000000","from":"0x0000000000000000000000000000000000000000","to":"0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48"}' \
  | 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.sitecheck-api.workers.dev%2Fapi%2Fevm%2Fsimulate&method=POST
const res = await pay("https://api.sitecheck-api.workers.dev/api/evm/simulate", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "chain": "ethereum",
    "data": "0x70a082310000000000000000000000000000000000000000000000000000000000000000",
    "from": "0x0000000000000000000000000000000000000000",
    "to": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48"
  }),
});
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.sitecheck-api.workers.dev/api/evm/simulate",
        json={
            "chain": "ethereum",
            "data": "0x70a082310000000000000000000000000000000000000000000000000000000000000000",
            "from": "0x0000000000000000000000000000000000000000",
            "to": "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
        },
    )
    print(res.status_code, res.text)

Security scan

No findings

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Recent checks

WhenResultHTTPTimePrice
55 min agoPassed40241 ms$0.003
5 h agoPassed40236 ms$0.003