Jon Staab@welshman/util 
Some nostr-specific utilities. For the most part, these will not have side effects or manage state. Includes:
- Event kind constants
- A nostr address class
- Utilities for working with nostr filters and tags
- Helpers for working with zap events and lightning invoices
- A
Encryptablefor ensuring payloads get encrypted - An implementation of an in-memory relay, backed by an events repository
- Utilities for building events, validating signatures, and checking event type (replaceable, etc.)
- Types and utilities for NIP 89 handlers
- Types and utilities for NIP 51 lists
- Types and utilities for NIP 01 profile metadata
- Types and utilities for NIP 11 relay profiles