Just for fun. What is the shortest micropython server for ON/OFF-type socket? Have not tested this yet:

    import network,socket,time

    sta_if = network.WLAN(network.STA_IF)
    if not sta_if.isconnected():
        sta_if.active(True)
        sta_if.connect('wifi', 'password')
        while not sta_if.isconnected():  pass

    from machine import Pin
    
    relayON =Pin(5, Pin.OUT)  
           
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.bind(('', 80))
    s.listen(5)
    
    while True:
        s.settimeout(0.5)
        try:
            conn, addr = s.accept()
            request = conn.recv(1024)
            request = str(request)
            if request.find('/ON') == 6:
                relayON.value(1)
            if request.find('/OFF') == 6:
                relayON.value(0)
            conn.close()
        except: pass