04 – WebSocket Echo

Handles the WebSocket protocol:

1. Waits for websocket.connect.
2. Sends websocket.accept to complete the handshake.
3. Echoes incoming frames back via websocket.send.
4. Stops when websocket.disconnect arrives or when websocket.receive contains neither text nor bytes.

Quick Start

1. Start the server:

pagi-server --app examples/04-websocket-echo/app.pl --port 5000

2. Demo with websocat:

# Install websocat if needed
brew install websocat        # macOS
# or: cargo install websocat  # with Rust

# Connect and send messages
websocat ws://localhost:5000/
# Type: Hello
# => Hello
# Type: PAGI WebSocket!
# => PAGI WebSocket!

3. Or use JavaScript in browser console:

const ws = new WebSocket('ws://localhost:5000/');
ws.onmessage = (e) => console.log('Received:', e.data);
ws.onopen = () => ws.send('Hello from browser!');

Spec References

• WebSocket scope & events – PAGI::Spec::Www