I did search messages in the community area before seeking more help. I know that it possible through Visual Studio (to backtest using the API) and that there was a QCRestAPI available to be used in C# classes.

I can no longer find anything on the API page - https://www.quantconnect.com/api/ . And furthermore I can't find the QCRestAPI repository on Github apart from one that seems to have been forked/modified by an individual rather than coming directly from QuantConnect.

It is my aim to use my own interface to connect to QuantConnects API for both backtesting and live trading. Is there a way that that can work or is it best a setup my own server on to which I setup LEAN?