Gas Price Oracle library for Ethereum dApps

A library that has a collection of onchain and offchain gas price oracle URLs

Supported networks

Ethereum Mainnet

Current offchain list:

• https://ethgasstation.info/json/ethgasAPI.json
• https://etherchain.org/api/gasnow
• https://blockscout.com/eth/mainnet/api/v1/gas-price-oracle

Current onchain list:

• chainlink

Binance Smart Chain

Current offchain list:

• https://ztake.org/

xDAI Chain

Current offchain list:

• https://blockscout.com/xdai/mainnet/api/v1/gas-price-oracle

Polygon (Matic) Network

Current offchain list:

• https://gasstation-mainnet.matic.network/

Installation

npm i gas-price-oracle

Import

const { GasPriceOracle } = require('gas-price-oracle');

Usage

Basic

const options = {
  chainId: 1,
  defaultRpc: 'https://api.mycryptoapi.com/eth',
  timeout: 10000,
  defaultFallbackGasPrices: {
    instant: 28,
    fast: 22,
    standard: 17,
    low: 11,
  },
};
const oracle = new GasPriceOracle(options);
// optional fallbackGasPrices
const fallbackGasPrices = {
  instant: 70,
  fast: 31,
  standard: 20,
  low: 7,
};
oracle.gasPrices(fallbackGasPrices).then(gasPrices => {
  console.log(gasPrices); // { instant: 50, fast: 21, standard: 10, low: 3 }
});

The gasPrices method also accepts median argument (true) by default. For more details see below. Under the hood it's a combination of fetchMedianGasPriceOffChain(fetchGasPricesOffChain) and fetchGasPricesOnChain methods.

Offchain oracles only

const oracle = new GasPriceOracle();

oracle.fetchGasPricesOffChain().then(gasPrices => {
  console.log(gasPrices); // { instant: 50, fast: 21, standard: 10, low: 3 }
});

Offchain oracles only (get median price)

const oracle = new GasPriceOracle();

oracle.fetchMedianGasPriceOffChain().then(gasPrices => {
  console.log(gasPrices); // { instant: 50, fast: 21, standard: 10, low: 3 }
});

it returns the median gas price of all the oracles configured.

Custom RPC URL for onchain oracles

const defaultRpc = 'https://mainnet.infura.io/v3/<API_KEY>';
const oracle = new GasPriceOracle({ defaultRpc });

oracle.fetchGasPricesOnChain().then(gasPrices => {
  console.log(gasPrices); // 21
});