Built and self-hosting a paid Nostr relay and a NIP-90 Data Vending Machine on a small VPS.

Relay: wss://5.78.129.127.nip.io/relay

• 1,000 sats (Lightning) for lifetime write access, free reads
• Custom Node.js + SQLite (WAL mode) implementation
• NIP-42 AUTH + automated Lightning invoicing via Coinos
• ~27MB RAM usage
• NIPs: 01, 02, 04, 09, 11, 12, 16, 20, 33, 42

DVM (Data Vending Machine):

• NIP-90 content extraction service
• 100 sats per URL extraction request
• Auto-generates Lightning invoices, delivers results as kind 6300 events
• ~38MB RAM

Both run as systemd services with auto-restart. Total infrastructure cost: one small VPS. Payment flow is fully automated — no manual intervention.

The paid relay model works well for spam prevention while generating passive income. Happy to share technical details if anyone is interested in running something similar.

Stack: Node.js, ws, better-sqlite3, nostr-tools, nginx reverse proxy, Let’s Encrypt SSL