websocket-client

Overview

The websocket-client node connects to a remote WebSocket server and outputs messages received over the connection. It supports automatic reconnection, ping/pong keep-alive, and optional per-message compression. Ideal for consuming real-time data streams such as cryptocurrency prices, IoT telemetry feeds, and live event data.

Properties

Connection Status

The node displays connection status visually and can emit status events:

Example: Live Crypto Price Feed

Connect to a cryptocurrency exchange WebSocket API to receive live BTC/USD price updates. The node auto-reconnects if the exchange drops the connection.

// websocket-client node configuration
{
  "url": "wss://stream.binance.com/ws/btcusdt@trade",
  "autoReconnect": true,
  "reconnectDelay": 3000,
  "pingInterval": 30000,
  "enableCompression": false
}

// Each incoming WebSocket message becomes msg.payload:
{
  "payload": "{\"e\":\"trade\",\"s\":\"BTCUSDT\",\"p\":\"43250.50\",\"q\":\"0.015\"}",
  "_msgid": "ws001"
}

// Connect to a json-parser node to parse the string,
// then use a function node to extract price:
// msg.payload = parseFloat(msg.payload.p);
// msg.topic = "crypto/btc/usd";
// return msg;

Example: Real-time IoT Data Stream

Connect to a central IoT gateway broadcasting sensor readings over WebSocket. Uses compression to reduce bandwidth on constrained networks.

// websocket-client node configuration
{
  "url": "wss://iot-gateway.local:8443/sensors/stream",
  "autoReconnect": true,
  "reconnectDelay": 5000,
  "pingInterval": 15000,
  "enableCompression": true
}

// Incoming message from IoT gateway:
{
  "payload": {
    "device_id": "rpi-sensor-03",
    "readings": {
      "temperature": 22.8,
      "humidity": 58,
      "pressure": 1013.25
    },
    "timestamp": "2024-01-15T14:30:00Z"
  },
  "_msgid": "ws002"
}

// Route to dashboard gauge nodes for display
// or to database nodes for storage

Example: Home Assistant Event Stream

Subscribe to Home Assistant state change events via its WebSocket API.

// websocket-client node configuration
{
  "url": "ws://homeassistant.local:8123/api/websocket",
  "autoReconnect": true,
  "reconnectDelay": 10000,
  "pingInterval": 30000,
  "enableCompression": false
}

// After authentication, subscribe to events:
// Send via a linked websocket-out:
// { "type": "subscribe_events", "event_type": "state_changed" }

// Incoming state change event:
{
  "payload": {
    "type": "event",
    "event": {
      "event_type": "state_changed",
      "data": {
        "entity_id": "sensor.living_room_temp",
        "new_state": { "state": "23.5" }
      }
    }
  }
}

Common Use Cases