ToolVet
78trust / 100

Tx Simulate

by TrollBridge in Onchain & crypto

x402 APIPassing, checked 3 h ago

NOT AN AUDIT — simulation, not a guarantee: transaction dry-run ($0.10) — simulate any call against live public RPCs before you send it: would-succeed vs would-revert verdict, revert reason decoded, gas estimate in native + USD. Toll: $0.10 USDC on Base or Solana.

GET
https://mini-tollbooth.onrender.com/tx-simulate
Price
$0.1
per call in USDC
Uptime
100%
last 30 days
Response time
218 ms
654 ms slowest 5%
Last check
Passed
3 h 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

How to call it

GET https://mini-tollbooth.onrender.com/tx-simulate

Each call costs $0.1 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://mini-tollbooth.onrender.com/tx-simulate?chain=base&data=0x095ea7b30000000000000000000000008be8d056d5f0bef850ec9ed5c4a8d647cbe896c0ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff&from=0x8BE8D056d5F0bEF850eC9ed5C4a8d647cBE896C0&to=0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913

Parameters

ParameterTypeRequiredDescription
chainstringNoWhich chain (default base). One of: base, ethereum.
datastringYesHex calldata of the transaction (0x…).
fromstringYesWallet address that would send the transaction (0x…).
tostringYesTarget contract address the transaction calls (0x… on Base or Ethereum).
valuestringNoNative currency value in wei, decimal or 0x… hex (default 0).

Example response

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

{
  "chain": "base",
  "description": "NOT AN AUDIT — simulation, not a guarantee: transaction dry-run ($0.10) — simulate any call against live public RPCs before you send it: would-succeed vs would-revert verdict, revert reason decoded, gas estimate in native + USD.",
  "gas_estimate": {
    "cost_native": "1.4e-7",
    "cost_usd_approx": 0.0004,
    "gas_units": 23697
  },
  "lane": "/tx-simulate",
  "revert_reason": null,
  "simulation": "eth_call + estimateGas against live public RPCs",
  "verdict": "would-succeed"
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.1.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://mini-tollbooth.onrender.com/tx-simulate?chain=base&data=0x095ea7b30000000000000000000000008be8d056d5f0bef850ec9ed5c4a8d647cbe896c0ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff&from=0x8BE8D056d5F0bEF850eC9ed5C4a8d647cBE896C0&to=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 - 'https://mini-tollbooth.onrender.com/tx-simulate?chain=base&data=0x095ea7b30000000000000000000000008be8d056d5f0bef850ec9ed5c4a8d647cbe896c0ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff&from=0x8BE8D056d5F0bEF850eC9ed5C4a8d647cBE896C0&to=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 $0.1 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.1" });
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 $0.1 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fmini-tollbooth.onrender.com%2Ftx-simulate
const res = await pay("https://mini-tollbooth.onrender.com/tx-simulate?chain=base&data=0x095ea7b30000000000000000000000008be8d056d5f0bef850ec9ed5c4a8d647cbe896c0ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff&from=0x8BE8D056d5F0bEF850eC9ed5C4a8d647cBE896C0&to=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 $0.1 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.1"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://mini-tollbooth.onrender.com/tx-simulate?chain=base&data=0x095ea7b30000000000000000000000008be8d056d5f0bef850ec9ed5c4a8d647cbe896c0ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff&from=0x8BE8D056d5F0bEF850eC9ed5C4a8d647cBE896C0&to=0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913")
    print(res.status_code, res.text)

Security scan

No findings

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Recent checks

WhenResultHTTPTimePrice
3 h agoPassed402737 ms$0.1
7 h agoPassed402255 ms$0.1
11 h agoPassed402203 ms$0.1
15 h agoPassed402554 ms$0.1
20 h agoPassed402601 ms$0.1
Show 10 older checks
24 h agoPassed402654 ms$0.1
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36 h agoPassed402191 ms$0.1
39 h agoPassed402213 ms$0.1
43 h agoPassed402208 ms$0.1
47 h agoPassed402218 ms$0.1
2 days agoPassed402206 ms$0.1
2 days agoPassed402189 ms$0.1
2 days agoPassed402223 ms$0.1