Web3 Builder


This package simplifies the process to create your own Web3 instance, change the active wallet, and update the connection to the Ethereum network.

This is made possible using building blocks called subproviders. Subproviders are like normal web3 providers, but only handle a subset of RPC methods. They can be used to route, or otherwise handle, RPC calls before returning a result to the caller.

web3-builder uses sub-providers to build out the Web3 object like so:

If you'd like more flexibility when creating Web3 Providers consider using web3-provider-engine directly.



npm install @radarrelay/web3-builder


yarn add @radarrelay/web3-builder


Web3 Creation

import { Web3Builder } from '@radarrelay/web3-builder';
import { InjectedWeb3Subprovider } from '@radarrelay/subproviders';
const walletSubprovider = new InjectedWeb3Subprovider(window.web3.currentProvider);
let web3 = Web3Builder.createWeb3(walletSubprovider, InfuraNetwork.Kovan);

Update Wallet

import { EthLightwalletSubprovider } from '@radarrelay/subproviders';
const newWalletSubprovider = new EthLightwalletSubprovider(signing, keystore, pwDerivedKey);
// Updating the wallet returns a new instance of web3
web3 = Web3Builder.updateWallet(newWalletSubprovider);

Update Network

// Updating the rpc connection returns a new instance of web3
web3 = Web3Builder.updateRpcConnection(InfuraNetwork.Mainnet);

Grab the Provider

Want to use your own version of Web3?

You can grab the Ethereum Provider and instantiate your preferred version of Web3:

import * as Web3 from 'web3';
const anotherWeb3Instance = new Web3(web3.currentProvider);


import * as Web3 from 'web3';
const anotherWeb3Instance = new Web3(web3Builder.provider);