logos-messaging-js/packages/relay/src/create.ts

import { CreateNodeOptions, RelayNode } from "@waku/interfaces";
import { createLibp2pAndUpdateOptions, WakuNode } from "@waku/sdk";

import { Relay, RelayCreateOptions, wakuGossipSub } from "./relay.js";

/**
 * Create a Waku node that uses Waku Relay to send and receive messages,
 * enabling some privacy preserving properties.
 * * @remarks
 * This function creates a Relay Node using the Waku Relay protocol.
 * While it is technically possible to use this function in a browser environment,
 * it is not recommended due to potential performance issues and limited browser capabilities.
 * If you are developing a browser-based application, consider alternative approaches like creating a Light Node
 * or use this function with caution.
 */
export async function createRelayNode(
  options: CreateNodeOptions & RelayCreateOptions
): Promise<RelayNode> {
  options = {
    ...options,
    libp2p: {
      ...options.libp2p,
      services: {
        pubsub: wakuGossipSub(options)
      }
    }
  };

  const libp2p = await createLibp2pAndUpdateOptions(options);

  const pubsubTopics = options.routingInfos.map((ri) => ri.pubsubTopic);

  const relay = new Relay({
    pubsubTopics,
    libp2p
  });

  const node = new WakuNode(
    options as CreateNodeOptions,
    libp2p,
    {},
    relay
  ) as RelayNode;

  // only if `false` is passed explicitly
  if (options?.autoStart !== false) {
    await node.start();
  }

  return node;
}