saepenatus/packages/gas/README.md

Web3-Onboard makes it simple to connect Ethereum hardware and software wallets to your dapp. Features standardised spec compliant web3 providers for all supported wallets, framework agnostic modern javascript UI with code splitting, CSS customization, mul

# @web3-onboard/gas

## A module for requesting streams or single requests of gas price estimates from the [Blocknative Gas Platform API](https://onboard.blocknative.com/docs/packages/gas).

Supports both Eth Mainnet and Polygon gas pricing.

### Install

**NPM**
`npm i @web3-onboard/gas`

**Yarn**
`yarn add @web3-onboard/gas`

### Standalone Setup

```typescript
import gas from '@web3-onboard/gas'

// subscribe to a single chain for estimates using the default poll rate of 5 secs
// API key is optional and if provided allows for faster poll rates
const ethMainnetGasBlockPrices = gas.stream({
  chains: ['0x1'],
  apiKey: '<OPTIONAL_API_KEY>',
  endpoint: 'blockPrices'
})

const { unsubscribe: ethGasUnsub } = ethMainnetGasBlockPrices.subscribe(
  estimates => console.log(estimates)
)

// .... sometime later, unsubscribe to stop polling
setTimeout(ethGasUnsub, 10000)

// OR you can subscribe to multiple chains at once:
const gasBlockPrices = gas.stream({
  chains: ['0x1', '0x89'],
  apiKey: '<OPTIONAL_API_KEY>',
  endpoint: 'blockPrices',
  // can override default poll rate as well
  poll: 1000
})

const { unsubscribe } = gasBlockPrices.subscribe(estimates =>
  console.log(estimates)
  console.log(estimates[0].blockPrices[0].estimatedPrice)
  // block inclusion confidence options: 70, 80, 90, 95, 99
  console.log(bnGasPrices.find(gas => gas.confidence === 90))
)

// .... sometime later, unsubscribe to stop polling
setTimeout(unsubscribe, 10000)

// Can also just do a one time get rather than a stream
const gasBlockPrices = await gas.get({
  chains: ['0x1', '0x89'],
  apiKey: '<OPTIONAL_API_KEY>',
  endpoint: 'blockPrices'
})
```


## Usage with Web3-Onboard wallet Connect and Ethers.js

This example assumes you have already setup web3-onboard to connect wallets to your dapp. 
For more information see [web3-onboard docs](https://onboard.blocknative.com/docs/modules/core#install).
```ts
import gas from '@web3-onboard/gas'
import { ethers } from 'ethers'

// Set provider using the Web3-Onboard wallet.provider instance from the connected wallet
let provider = new ethers.providers.Web3Provider(wallet.provider, 'any')
let bnGasPrices

const ethMainnetGasBlockPrices = gas.stream({
  chains: ['0x1'], // '0x89' can also be added/replaced here for Polygon gas data 
  apiKey: '<OPTIONAL_API_KEY>', // for faster refresh rates
  endpoint: 'blockPrices'
})

ethMainnetGasBlockPrices.subscribe(estimates => {
  console.log(estimates)
  bnGasPrices = estimates[0].blockPrices[0].estimatedPrices
})


const gweiToWeiHex = gwei => {
  return `0x${(gwei * 1e9).toString(16)}`
}

const sendTransaction = async () => {
  if (!toAddress) {
    alert('An Ethereum address to send Eth to is required.')
    return
  }

  const signer = provider.getUncheckedSigner()
  
  // define desired confidence for transaction inclusion in block and set in transaction
  // block inclusion confidence options: 70, 80, 90, 95, 99
  const bnGasForTransaction = bnGasPrices.find(gas => gas.confidence === 90)

  const rc = await signer.sendTransaction({
    to: toAddress,
    value: 1000000000000000

    // This will set the transaction gas based on desired confidence
    maxPriorityFeePerGas: gweiToWeiHex(
      bnGasForTransaction.maxPriorityFeePerGas
    ),
    maxFeePerGas: gweiToWeiHex(bnGasForTransaction.maxFeePerGas)
  })
  console.log(rc)
}
```