NomadServer

Bitcoin server for NomadWallet - communicates with mobile wallet via Nostr protocol.

Structure

• app/server/ - Rust backend server (Nostr relay connections, NIP-44 encryption)
• app/ui/ - Web UI for the Umbrel app (future)
• protocol/ - Nostr protocol definitions and utilities
• docker/ - Docker configuration files
• umbrel/ - Umbrel-specific configuration and metadata

Technology Stack

• Rust - Backend server implementation
• nostr-sdk - Nostr protocol and relay connections
• NIP-44 - Encryption for secure communication
• Tokio - Async runtime

Building

cargo build --release

Running

cargo run --bin nomad-server

Docker

Running with Docker on Umbrel

To run NomadServer as a Docker container on your Umbrel node:

docker run -d \
  --name nomadserver \
  --network umbrel_main_network \
  -p 3829:3829 \
  -e ELECTRS_ADDR=electrs:50001 \
  -e RUST_LOG=info \
  -v nomadserver-data:/data \
  zenderady/nomad-server:latest

Parameters:

• --name nomadserver - Container name
• --network umbrel_main_network - Connects to Umbrel's main network
• -p 3829:3829 - Exposes port 3829 for the web interface
• -e ELECTRS_ADDR=electrs:50001 - Electrs server address
• -e RUST_LOG=info - Logging level
• -v nomadserver-data:/data - Persistent data volume
• zenderady/nomad-server:latest - Docker image

After starting, access the web interface at http://your-umbrel-ip:3829

Development

cargo run

Features

• ✅ Connects to public Nostr relays
• ✅ Uses NIP-44 encryption
• 🔜 Will integrate with Fulcrum/Electrs for Bitcoin data

Communication Architecture

Mobile (Android) Communication

• Exclusively via Nostr protocol - No REST, GraphQL, or WebSocket APIs
• NIP-44 encrypted events - All mobile communication is encrypted using NIP-44
• Public relays - Events are sent/received over public Nostr relays
• No direct HTTP endpoints - Android app never makes HTTP requests to this server

Web UI Communication

• Local to Umbrel only - Web UI is only accessible within the Umbrel network
• Direct server communication - UI can use HTTP/WebSocket for local Umbrel interface