L2 gas comparison

Current gas snapshot across Ethereum + supported L2s (Base, Polygon, Arbitrum, Optimism), sorted cheapest-first. Returns gas price in gwei, latest block number, chain id, and an isL2 flag per chain. Use to route a transaction to the cheapest viable L2 or to track L1→L2 gas spread.

Input

Example output

{
  "queriedAt": "2026-06-22T19:00:00.000Z",
  "networks": [
    {
      "network": "base",
      "chainId": 8453,
      "isL2": true,
      "gasPriceWei": "100000000",
      "gasPriceGwei": 0.1,
      "blockNumber": 22000000
    },
    {
      "network": "arbitrum",
      "chainId": 42161,
      "isL2": true,
      "gasPriceWei": "100000000",
      "gasPriceGwei": 0.1,
      "blockNumber": 300000000
    },
    {
      "network": "ethereum",
      "chainId": 1,
      "isL2": false,
      "gasPriceWei": "15000000000",
      "gasPriceGwei": 15,
      "blockNumber": 22000000
    }
  ],
  "cheapest": "base",
  "source": "alchemy"
}

Try it - see the 402 challenge (free)

curl -i -X POST https://agent402.tools/api/l2-gas-comparison \
  -H "Content-Type: application/json" \
  -d '{"networks":["ethereum","base","arbitrum","optimism","polygon"]}'

The response is HTTP 402 Payment Required with exact payment requirements. Any x402 v2 client pays automatically and retries:

Paid call (JavaScript agent)

import { wrapFetchWithPayment } from "@x402/fetch";
import { x402Client } from "@x402/core/client";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

const client = new x402Client();
registerExactEvmScheme(client, { signer: privateKeyToAccount(KEY) });
const payFetch = wrapFetchWithPayment(fetch, client);

const res = await payFetch("https://agent402.tools/api/l2-gas-comparison", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    "networks": [
      "ethereum",
      "base",
      "arbitrum",
      "optimism",
      "polygon"
    ]
  }),
});

Part of these workflows

This tool is one step in a curated multi-tool workflow - agents can fetch the whole sequence as an MCP prompt or call https://agent402.tools/api/skill-packs/{slug}/prompt.

• Cheapest rail right now - Where should an agent transact this minute? Live gas on Ethereum + every major L2 side by side, Base gas tiers, a fee estimate for your transaction type, and ETH spot to price it all in dollars.

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