84 lines
2.3 KiB
Markdown
84 lines
2.3 KiB
Markdown
# Gas Price Oracle library for Ethereum dApps [](https://github.com/peppersec/gas-price-oracle/actions) [](https://www.npmjs.com/package/gas-price-oracle)
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A library that has a collection of onchain and offchain gas price oracle URLs
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Current offchain list:
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- https://ethgasstation.info/json/ethgasAPI.json
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- https://gas-oracle.zoltu.io/
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- https://www.etherchain.org/api/gasPriceOracle
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- https://gasprice.poa.network/
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- https://www.gasnow.org/api/v3/gas/price
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Current onchain list:
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- [chainlink](https://etherscan.io/address/0x169e633a2d1e6c10dd91238ba11c4a708dfef37c#readContract)
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## Installation
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`npm i gas-price-oracle`
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## Import
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```js
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const { GasPriceOracle } = require('gas-price-oracle');
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```
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## Usage
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### Basic
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```js
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const options = {
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defaultRpc: 'https://api.mycryptoapi.com/eth',
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timeout: 10000,
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};
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const oracle = new GasPriceOracle(options);
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// optional fallbackGasPrices
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const fallbackGasPrices = {
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instant: 70,
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fast: 31,
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standard: 20,
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low: 7,
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};
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oracle.gasPrices(fallbackGasPrices).then(gasPrices => {
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console.log(gasPrices); // { instant: 50, fast: 21, standard: 10, low: 3 }
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});
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```
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The `gasPrices` method also accepts `median` argument (`true`) by default. For more details see [below](#offchain-oracles-only-get-median-price).
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Under the hood it's a combination of `fetchMedianGasPriceOffChain`(`fetchGasPricesOffChain`) and `fetchGasPricesOnChain` methods.
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### Offchain oracles only
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```js
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const oracle = new GasPriceOracle();
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oracle.fetchGasPricesOffChain().then(gasPrices => {
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console.log(gasPrices); // { instant: 50, fast: 21, standard: 10, low: 3 }
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});
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```
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### Offchain oracles only (get median price)
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```js
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const oracle = new GasPriceOracle();
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oracle.fetchMedianGasPriceOffChain().then(gasPrices => {
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console.log(gasPrices); // { instant: 50, fast: 21, standard: 10, low: 3 }
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});
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```
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it returns the median gas price of all the oracles configured.
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### Custom RPC URL for onchain oracles
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```js
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const defaultRpc = 'https://mainnet.infura.io/v3/<API_KEY>';
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const oracle = new GasPriceOracle({ defaultRpc });
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oracle.fetchGasPricesOnChain().then(gasPrices => {
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console.log(gasPrices); // 21
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});
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```
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