chain.openverbs.com

Simulate a transaction before signing: runs `eth_estimateGas` for `{ to, from?, data?, value? }` and returns the estimated gas units and estimated fee (current gas price x gas, in wei + ETH). If the node rejects the call it returns `ok:false` with the decoded `revertReason` (why it would fail) instead of erroring. Reads live on-chain state with automatic endpoint fallback.

Open endpoint ↗

Price per call: $0.004
Chain: Base
Method: POST
Paid calls · 30 days: 2

Call it from code

This API is run by its own provider and paid directly through x402. We list it so you can find it; we don't route or hold the payment.

import { x402Client, wrapFetchWithPayment } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";

const client = new x402Client();
registerExactEvmScheme(client, { signer: agentAccount });

const pay = wrapFetchWithPayment(fetch, client);
const res = await pay("https://chain.openverbs.com/v1/gas-estimate", { method: "POST" });
console.log(await res.json());

https://chain.openverbs.com/v1/gas-estimate