Estimate Gas for Transactions - Para Docs

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Accurately estimate gas costs for transactions to ensure reliable execution without overpaying. This guide covers gas estimation for simple transfers and smart contract interactions using , , and .

Prerequisites

You need Web3 libraries configured with Para authentication.

Estimate Gas for a Transaction

Ethers.js
Viem
Wagmi

import { ethers } from "ethers";

async function estimateGas(
  provider: ethers.Provider,
  to: string,
  value: string,
  data?: string,
  maxFeePerGas?: string,
  maxPriorityFeePerGas?: string
) {
  const tx = {
    to,
    value: ethers.parseEther(value),
    data: data || "0x",
    ...(maxFeePerGas ? { maxFeePerGas: ethers.parseUnits(maxFeePerGas, "gwei") } : {}),
    ...(maxPriorityFeePerGas ? { maxPriorityFeePerGas: ethers.parseUnits(maxPriorityFeePerGas, "gwei") } : {})
  };

  const gasEstimate = await provider.estimateGas(tx);
  return gasEstimate;
}

import { parseEther, parseGwei } from "viem";

async function estimateGas(
  publicClient: PublicClient,
  account: Account | `0x${string}`,
  to: `0x${string}`,
  value: string,
  data?: `0x${string}`,
  maxFeePerGas?: string,
  maxPriorityFeePerGas?: string
) {
  const gasEstimate = await publicClient.estimateGas({
    account,
    to,
    value: parseEther(value),
    data: data || "0x",
    ...(maxFeePerGas ? { maxFeePerGas: parseGwei(maxFeePerGas) } : {}),
    ...(maxPriorityFeePerGas ? { maxPriorityFeePerGas: parseGwei(maxPriorityFeePerGas) } : {})
  });
  return gasEstimate;
}

import { useEstimateGas } from "@getpara/react-sdk/wagmi";
import { parseEther, parseGwei } from "viem";

function EstimateGas({
  to,
  value,
  data,
  maxFeePerGas,
  maxPriorityFeePerGas,
}: {
  to: `0x${string}`;
  value: string;
  data?: `0x${string}`;
  maxFeePerGas?: string;
  maxPriorityFeePerGas?: string;
}) {
  const { data: gas } = useEstimateGas({
    to,
    value: parseEther(value),
    data: data || "0x",
    ...(maxFeePerGas ? { maxFeePerGas: parseGwei(maxFeePerGas) } : {}),
    ...(maxPriorityFeePerGas ? { maxPriorityFeePerGas: parseGwei(maxPriorityFeePerGas) } : {})
  });

  return (
    // Your component JSX here
  )
}