XSWD Relayer

XSWD Relayer is a lightweight, high-performance WebSocket tunnel designed to connect exactly two peers via a temporary secure channel.

It forwards messages in both directions, with zero inspection or transformation.

This makes it ideal for building trustless communication layers, encrypted tunnels, or peer-to-peer protocols over WebSocket.

🛠 How It Works

1. A client connects to /ws and receives a channel UUID.
2. Another client connects to /ws/{uuid} using that channel ID.
3. Once two peers are connected, all WebSocket messages from one are proxied to the other.
4. If either client disconnects, the channel is closed and removed.

Note: The relayer is content-agnostic. You can layer encryption (e.g. AES-GCM) and authentication (e.g. HMAC, digital signatures) over the tunneled messages.

🔒 Why XSWD Relayer?

The XSWD protocol enables secure communication between a dApp and a XELIS wallet. However, this becomes problematic when the wallet is running on a separate device — for example:

• The wallet is on your phone
• The dApp runs on your desktop browser

In this setup, direct communication is not possible. That’s where XSWD Relayer comes in.

It acts as a bridge, allowing the desktop dApp and mobile wallet to communicate safely — without trusting the relayer.

🧠 How it stays secure

To prevent MITM attacks or data leaks, the JavaScript SDK:

• Generates a random encryption key
• Uses it to encrypt and authenticate all messages exchanged with the wallet
• Embeds the channel ID, encryption key, and relayer URL inside a QR Code

The wallet scans the QR code and connects securely to the same channel. Since all messages are end-to-end encrypted and authenticated, even if the relayer is compromised, your data remains safe.

📦 Usage

Run the Server

cargo run --release

Also see --help for all the available configurations.