eth-gas-estimator-lite

Minimal Ethereum gas price estimator via Etherscan (low/medium/high in Gwei).

Table of Contents

• Description
• Installation
• Usage
• API
• Example
• Options
• Error Handling
• License

Description

eth-gas-estimator-lite is a tiny TypeScript/JavaScript library that fetches “low”, “medium” (proposed), and “high” gas-price tiers from Etherscan’s Gas Oracle API, returning all values in Gwei. It’s ideal for dApps and scripts that need simple, zero-boilerplate gas-price suggestions.

Installation

npm install eth-gas-estimator-lite axios

Or

yarn add eth-gas-estimator-lite axios

Usage

Import and call the fetchGasPrices function, supplying your Etherscan API key:

import { fetchGasPrices } from "eth-gas-estimator-lite";

(async () => {
  const { low, medium, high } = await fetchGasPrices({
    apiKey: "YOUR_API_KEY",
  });
  console.log(`Low: ${low} Gwei`);
  console.log(`Medium: ${medium} Gwei`);
  console.log(`High: ${high} Gwei`);
})();

API

fetchGasPrices(opts: EstimatorOptions): Promise<GasPrices>

Parameters

• opts.apiKey (string, required): Your Etherscan API key.

Returns

• Promise<GasPrices> where GasPrices is:

interface GasPrices {
  low: number; // SafeGasPrice (Gwei)
  medium: number; // ProposeGasPrice (Gwei)
  high: number; // FastGasPrice (Gwei)
}

Example

import { fetchGasPrices } from "eth-gas-estimator-lite";
import { ethers } from "ethers";
import * as dotenv from "dotenv";
dotenv.config();

async function sendTransaction(signer: ethers.Signer) {
  const { low, medium, high } = await fetchGasPrices({
    apiKey: process.env.ETHERSCAN_API_KEY!,
  });

  const tx = await signer.sendTransaction({
    to: "0xRecipientAddressHere",
    value: ethers.utils.parseEther("0.1"),
    gasPrice: ethers.utils.parseUnits(medium.toString(), "gwei"),
  });

  console.log("Transaction hash:", tx.hash);
}

Options

The only supported option is:

interface EstimatorOptions {
  apiKey: string; // Etherscan API key (required)
}

Error Handling

• Throws if apiKey is missing or empty.
• Throws if the API call fails, or if Etherscan responds with status !== '1'.
• Errors include the Etherscan message when available.

License

This project is licensed under the MIT License. See LICENSE for details.