Gas Compare

{
  "action": "swap",
  "chains": [
    {
      "base_fee_gwei": 0.000001021,
      "chain": "optimism",
      "cost_native": 3.3911e-9,
      "cost_usd": 0.00000856,
      "gas_price_gwei": 0.00000152,
      "l1_data_fee_native": 3.118e-9,
      "native_price_usd": 2523.32,
      "native_token": "ETH",
      "priority_tip_gwei": 4.99e-7
    },
    {
      "base_fee_gwei": 0.005,
      "chain": "base",
      "cost_native": 0.0000010839,
      "cost_usd": 0.00273,
      "gas_price_gwei": 0.00601,
      "l1_data_fee_native": 2.06e-9,
      "native_price_usd": 2523.32,
      "native_token": "ETH",
      "priority_tip_gwei": 0.00101
    },
    {
      "base_fee_gwei": 245.69,
      "chain": "polygon",
      "cost_native": 0.059813,
      "cost_usd": 0.00613,
      "gas_price_gwei": 332.29,
      "l1_data_fee_native": 0,
      "native_price_usd": 0.10247,
      "native_token": "POL",
      "priority_tip_gwei": 86.598
    },
    {
      "base_fee_gwei": 0,
      "chain": "bsc",
      "cost_native": 0.0000091133,
      "cost_usd": 0.00681,
      "gas_price_gwei": 0.050629,
      "l1_data_fee_native": 0,
      "native_price_usd": 747.08,
      "native_token": "BNB",
      "priority_tip_gwei": 0.050629
    },
    {
      "base_fee_gwei": 0.020158,
      "chain": "arbitrum",
      "cost_native": 0.000003653,
      "cost_usd": 0.00922,
      "gas_price_gwei": 0.020158,
      "l1_data_fee_native": 2.451e-8,
      "native_price_usd": 2523.32,
      "native_token": "ETH",
      "priority_tip_gwei": 0
    },
    {
      "base_fee_gwei": 5.0005,
      "chain": "avalanche",
      "cost_native": 0.0013501,
      "cost_usd": 0.0143,
      "gas_price_gwei": 7.5005,
      "l1_data_fee_native": 0,
      "native_price_usd": 10.568,
      "native_token": "AVAX",
      "priority_tip_gwei": 2.5
    },
    {
      "base_fee_gwei": 0.11063,
      "chain": "ethereum",
      "cost_native": 0.000035339,
      "cost_usd": 0.0892,
      "gas_price_gwei": 0.19633,
      "l1_data_fee_native": 0,
      "native_price_usd": 2523.32,
      "native_token": "ETH",
      "priority_tip_gwei": 0.085694
    },
    {
      "base_fee_gwei": 7e-9,
      "chain": "linea",
      "cost_native": 0.000043667,
      "cost_usd": 0.1102,
      "gas_price_gwei": 0.24259,
      "l1_data_fee_native": 0,
      "native_price_usd": 2523.32,
      "native_token": "ETH",
      "priority_tip_gwei": 0.24259
    }
  ],
  "chains_checked": 8,
  "chains_responding": 8,
  "cheapest": {
    "chain": "optimism",
    "cost_usd": 0.00000856
  },
  "cheapest_vs_most_expensive_x": 12873.8,
  "gas_units": 180000,
  "most_expensive": {
    "chain": "linea",
    "cost_usd": 0.1102
  },
  "note": "Gas price is the next-block base fee plus the median priority tip of the last 4 blocks. Base, Optimism and Arbitrum rows include an estimated L1 data fee for a typical signed payload of this action."
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://saylorinnovations.com/api/gas/compare?action=swap'

# 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://saylorinnovations.com/api/gas/compare?action=swap' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

// 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%2Fsaylorinnovations.com%2Fapi%2Fgas%2Fcompare
const res = await pay("https://saylorinnovations.com/api/gas/compare?action=swap");
console.log(res.status, await res.text());

# 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://saylorinnovations.com/api/gas/compare?action=swap")
    print(res.status_code, res.text)