clasp-discovery

Network discovery for CLASP (Creative Low-Latency Application Streaming Protocol) devices and servers.

Features

• mDNS/DNS-SD - Zero-configuration discovery on local networks
• UDP Broadcast - Fallback discovery when mDNS is unavailable
• Rendezvous Server - WAN discovery via HTTP REST API
• Cascade Discovery - Automatically try mDNS → broadcast → rendezvous
• Auto-Keepalive - Automatic registration refresh with rendezvous server

Feature Flags

Basic Usage

use clasp_discovery::Discovery;

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let mut discovery = Discovery::new();

    // Start discovering devices
    let mut rx = discovery.start().await?;

    // Process discovery events
    while let Some(event) = rx.recv().await {
        match event {
            clasp_discovery::DiscoveryEvent::Found(device) => {
                println!("Found: {} at {:?}", device.name, device.endpoints);
            }
            clasp_discovery::DiscoveryEvent::Lost(id) => {
                println!("Lost device: {}", id);
            }
            clasp_discovery::DiscoveryEvent::Error(e) => {
                eprintln!("Discovery error: {}", e);
            }
        }
    }

    Ok(())
}

WAN Discovery (Rendezvous)

For discovery across the internet, use the rendezvous feature:

[dependencies]
clasp-discovery = { version = "3.3", features = ["rendezvous"] }

use clasp_discovery::{Discovery, DiscoveryConfig, DeviceRegistration};
use std::time::Duration;

let config = DiscoveryConfig {
    // Use the public CLASP relay (includes rendezvous)
    rendezvous_url: Some("https://relay.clasp.to".into()),
    rendezvous_refresh_interval: Duration::from_secs(120),
    rendezvous_tag: Some("studio".into()),
    ..Default::default()
};

let mut discovery = Discovery::with_config(config);

// Register this device (starts automatic keepalive)
discovery.register_with_rendezvous(DeviceRegistration {
    name: "My Device".into(),
    endpoints: [("ws".into(), "wss://my-device.local:7330".into())].into(),
    tags: vec!["studio".into()],
    ..Default::default()
});

// Discover all devices (mDNS → broadcast → rendezvous)
let devices = discovery.discover_all().await?;

// Or discover WAN devices only
let wan_devices = discovery.discover_wan().await?;

Rendezvous Server

The rendezvous server is built into the CLASP relay server by default. When you run clasp-relay, rendezvous is automatically available on port 7340.

# Start relay with rendezvous (default)
clasp-relay --ws-port 7330 --rendezvous-port 7340

# Disable rendezvous
clasp-relay --rendezvous-port 0

You can also run a standalone rendezvous server:

use clasp_discovery::rendezvous::{RendezvousServer, RendezvousConfig};

let server = RendezvousServer::new(RendezvousConfig {
    ttl: 300,           // 5 minute registration TTL
    cleanup_interval: 60,
    ..Default::default()
});

server.serve("0.0.0.0:7340").await?;

mDNS Service Type

CLASP uses the service type _clasp._tcp.local for mDNS discovery.

Documentation

Visit clasp.to for full documentation.

License

Licensed under either of Apache License, Version 2.0 or MIT license at your option.

Maintained by LumenCanvas | 2026