Nostrclient - LNbits extension

For more about LNBits extension check this tutorial

Overview

nostrclient is an always-on Nostr relay multiplexer that simplifies connecting to multiple Nostr relays. Instead of your Nostr client managing connections to dozens of relays, you connect to a single WebSocket endpoint provided by nostrclient, which then fans out your requests to all configured relays and aggregates the responses back to you.

Why Use This?

• Simplified Client Configuration - Connect to one endpoint instead of managing multiple relay connections
• Always-On Connectivity - Your LNbits instance maintains persistent connections to relays
• Resource Efficient - Share relay connections across multiple clients
• Subscription Management - Automatic subscription ID rewriting prevents conflicts between clients

Architecture

flowchart LR
    A[Client A] -->|WebSocket| N
    B[Client B] -->|WebSocket| N
    C[Client C] -->|WebSocket| N

    N[nostrclient<br/>Router] -->|Fan Out| R1[Relay A]
    N -->|Fan Out| R2[Relay B]
    N -->|Fan Out| R3[Relay C]
    N -->|Fan Out| R4[Relay D]

    R1 -.->|Aggregate| N
    R2 -.->|Aggregate| N
    R3 -.->|Aggregate| N
    R4 -.->|Aggregate| N

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Key Feature: The router rewrites subscription IDs to prevent conflicts when multiple clients use the same IDs.

Features

• Multi-Relay Multiplexing - Connect to multiple Nostr relays through a single WebSocket
• Public & Private Endpoints - Configurable public and private WebSocket access
• Automatic Reconnection - Failed relays are automatically retried with exponential backoff
• Subscription Deduplication - Events are deduplicated before being sent to clients
• Health Monitoring - Track relay connection status, latency, and error rates
• Test Endpoint - Send test messages to verify your setup is working

How It Works

1. Client Connection - Your Nostr client connects to the nostrclient WebSocket endpoint
2. Subscription Rewriting - Each subscription ID is rewritten to prevent conflicts between multiple clients
3. Fan-Out - Subscription requests are sent to all configured relays
4. Aggregation - Events from all relays are collected and deduplicated
5. Response - Events are sent back to the client with the original subscription ID

Configuration

WebSocket Endpoints

• Public Endpoint: /api/v1/relay - Available to anyone (if enabled)
• Private Endpoint: /api/v1/{encrypted_id} - Requires valid encrypted endpoint ID

Configure endpoint access in the extension settings:

• private_ws - Enable/disable private WebSocket access
• public_ws - Enable/disable public WebSocket access

Adding Relays

Use the nostrclient UI to add/remove Nostr relays. The extension will automatically:

• Connect to new relays
• Publish existing subscriptions to new relays
• Monitor relay health and reconnect as needed

Testing

Test Endpoint Functionality

The Test Endpoint feature helps verify that your nostrclient WebSocket endpoint works correctly.

How to test:

1. Navigate to the nostrclient extension in LNbits
2. Use the Test Endpoint feature
3. Send a DM to yourself (or a temporary account)
4. Verify that messages are sent and received correctly

nostrclient_test.mp4

Troubleshooting

Connection Issues

• Check relay status - View relay health in the nostrclient UI
• Verify endpoint configuration - Ensure public_ws or private_ws is enabled
• Check logs - Review LNbits logs for connection errors

Subscription Not Receiving Events

• Verify relays are connected - Check the relay status in the UI
• Test with known event - Use the Test Endpoint to verify connectivity
• Check relay compatibility - Some relays may not support all Nostr features

Development

This extension uses uv for dependency management.

Quick Start

# Format code
make format

# Run type checks and linting
make check

# Run tests
make test

For more development commands, see the Makefile.

License

MIT License - see LICENSE