How to remote control OBS

Just for completeness, here is an example that also listens for responses:

function getConnection(port, alwaysReconnect) {
    /** @type {AxWebSocketClientConnection} */
    var connection = globalState.obsConnection;
    var messageHandlers = globalState.obsMessageHandlers = (globalState.obsMessageHandlers || {});
    if (connection && alwaysReconnect) {
        connection.close();
        globalState.obsConnection = null;
        connection = null;
    }
    if (!connection) {
        connection = sf.net.wsOpenClient({
            url: `ws://127.0.0.1:${port}/ws`,
            onMessage: msg => {
                var msgObj = msg.asJson();
                var msgId = msgObj['message-id'];
                var handler = messageHandlers[msgId];
                if (handler) {
                    delete messageHandlers[msgId];
                    handler(msgObj);
                }
            }
        }).connection;
        globalState.obsConnection = connection;
    }
    return connection;
}

function sendMessage(msg, callback) {
    var connection = getConnection(4444);
    var msgId = globalState.obsMessageCounter === undefined ? (globalState.obsMessageCounter = 1) : (++globalState.obsMessageCounter);
    msg['message-id'] = 'm' + msgId;
    if (callback) {
        globalState.obsMessageHandlers['m' + msgId] = callback;
    }
    connection.sendJson({
        json: msg
    });
}

function getSceneName(callback) {
    sendMessage({
        'request-type': 'GetCurrentScene',
    }, msg => {
        callback(msg['name']);
    });
}

getSceneName(name => {
    log('name: ' + name);
});

Alright, that could maybe explain some things :)
So maybe I will have to make a solution with something external from SF.