ToolVet
77trust / 100

Gas Compare

by base-gas-x402 in Onchain & crypto

x402 APIPassing, checked 2 h ago

Live gas cost comparison across Base, OP Mainnet, Arbitrum One, and Ethereum in one call, ranked cheapest first.

GET https://base-gas-x402-production.up.railway.app/gas/compare

Last 30 days

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Status and outage history · Atom feed

Uptime
100%
Response time
342 ms typical, 490 ms slowest 5%
Last check
2 h ago
Next check
any minute now

How to call it

GET https://base-gas-x402-production.up.railway.app/gas/compare

Each call costs $0.01 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://base-gas-x402-production.up.railway.app/gas/compare?gasLimit=21000

Parameters

ParameterTypeRequiredDescription
gasLimitintegerNoGas units to price each chain against. Defaults to 21000 (a plain ETH transfer). Default: 21000.

Example response

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

{
  "baseRank": 1,
  "baseVsEthereum": "Base is 240.5x cheaper than Ethereum",
  "basis": "current gas price x gasLimit",
  "chains": [
    {
      "baseFeePerGas": "0.005",
      "blockNumber": "49106604",
      "chain": "base",
      "chainId": 8453,
      "estimatedCost": {
        "eth": "0.000000126",
        "gasLimit": 21000,
        "gwei": "126"
      },
      "gasPrice": "0.006",
      "label": "Base"
    }
  ],
  "cheapest": "base",
  "fetchedAt": "2026-07-25T18:02:36.639Z",
  "gasLimit": 21000,
  "unavailable": []
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.01.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://base-gas-x402-production.up.railway.app/gas/compare?gasLimit=21000'

# 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://base-gas-x402-production.up.railway.app/gas/compare?gasLimit=21000' \
  | 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 $0.01 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.01" });
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 $0.01 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fbase-gas-x402-production.up.railway.app%2Fgas%2Fcompare
const res = await pay("https://base-gas-x402-production.up.railway.app/gas/compare?gasLimit=21000");
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 $0.01 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.01"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://base-gas-x402-production.up.railway.app/gas/compare?gasLimit=21000")
    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

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