ws_service.toit

import net
import http
import web_socket
import bytes
import gpio

IS_CONNECTED := false
SWITCH ::= gpio.Pin 16 --output 
HOST ::= "your-endpoint"
PORT ::= 80

main:
  print "Device Online"
  s := connect_server
  
  while true:
    if IS_CONNECTED == false:
      s = connect_server
      if s != null:
        IS_CONNECTED = true
      else:
        IS_CONNECTED = false
        sleep --ms=5000
    else if IS_CONNECTED == true:
      try:
        print "Waiting data"
        dc := catch:
          payload := s.read 
          if payload == "ON":
            SWITCH.set 1
          else if payload == "OFF":
            SWITCH.set 0 
        
          print "$payload"        
        if dc:
            IS_CONNECTED = false            
            SWITCH.set 0
      finally:
     
connect_server:
  network_interface := net.open
  socket := network_interface.tcp_connect HOST PORT
  http_connection := http.Connection socket HOST
  
  err := catch:
    request := http_connection.new_request "GET" "/ws"
    client := web_socket.WebSocketClient http_connection request
    return client
  
  if err:
    print "Server down, retry in 5s"
    
  return null

Where do you install web_socket from? There's really no information about this library anywhere.

Where do you install web_socket from? There's really no information about this library anywhere.

It's in their standard library. The documentation isn't the best so you'll have to try things out.
https://libs.toit.io/web_socket/library-summary