​
Creating a Node Provider

Node Providers form the backbone of Nexus. All blockchain access eventually needs to go through a Node Provider. Node providers can be created and configured as seen below. 
import {
  NodeProvider,
  CHAIN,
} from "@whatsgood/nexus";

const alchemyEthMainnetProvider = new NodeProvider({
  name: "alchemy",
  chain: CHAIN.ETHEREUM_MAINNET,
  url: process.env.ALCHEMY_URL,
});

const infuraEthMainnetProvider = new NodeProvider({
  name: "infura",
  chain: CHAIN.ETHEREUM_MAINNET,
  url: process.env.INFURA_URL,
});

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Load balancing

If you configure Nexus with multiple providers that support the same chain, Nexus can cycle requests between them. This is useful for load balancing and failovers. You can influence how a node provider gets selected by setting the weight property. See Load Balancing for more information. 
import {
  NodeProvider,
  CHAIN,
  Nexus,
} from "@whatsgood/nexus";

const alchemyEthMainnetProvider = new NodeProvider({
  name: "alchemy",
  chain: CHAIN.ETHEREUM_MAINNET,
  url: process.env.ALCHEMY_URL,
  weight: 3, // 30% of requests will go to this provider
});

const infuraEthMainnetProvider = new NodeProvider({
  name: "infura",
  chain: CHAIN.ETHEREUM_MAINNET,
  url: process.env.INFURA_URL,
  weight: 7, // 70% of requests will go to this provider
});

const nexus = Nexus.create({
  //...
  nodeProviders: [alchemyEthMainnetProvider, infuraEthMainnetProvider],
  relay: {
    order: "random",
  },
});