NWC and Nostr Relays

In Nostr, messages are sent through relays, websocket servers that store and deliver messages to subscribers. NIP-47 recommends that for NWC, VASPs might want to use a dedicated relay for privacy, security, and reliability reasons. Custom relays can optimize for NWC by enforcing authentication (NIP-42)[https://github.com/nostr-protocol/nips/blob/master/42.md] for requests, as well as tracking custom metrics, scaling as needed for the VASPs use case, and more.
For initial development, you can use a public relay like Alby's NWC relay at wss://relay.getalby.com/v1. This relay is open to all and is a good place to start testing your NWC integration. See Alby's NWC relay documentation for information about their relay.
For production, you may want to run your own for the reasons mentioned above. See this list of open-source relay implementations for a starting point.