Nostr: How do I protect myself from spam on Nostr?

Short answer

Use your client's mute controls, choose relays with policies you trust, and be cautious with unsolicited links and payment requests. NIP-51 defines shareable mute lists, but each client decides how to present and enforce them. Relay moderation can reduce spam on that server without removing it from every other relay. Reporting tools and trusted communities may help, depending on the app.

Sources

NIP-51: Lists, NIP-11: Relay metadata.