Ciaran!

You need to setup a connection to every workspace in VSCode.

Place your mac file into any folder. Preferably into 

/mycoding/testproject/src/myOSFile.mac

Then open this /testproject/src folder in VSCode.

Then go to VSCode Preferences and find CachéObjectScript settings section. It is what is used by default. If your current project differs from the default (e.g. another server connection or namespace) place it into UserSettings section on the right. Like it is shown in this gif:

You can check the connection in Output window of the terminal with name cos. 

Or you can just try to save any file - it tries to compile on save and will popup you the results.

HTH

Hi Sean! Moved the discussion to the Other group.

4,800+ are the registered members, stats. We also have about 20,000 unique DC visitors monthly.

From them we have about 3,000 visitors who come directly to the site - so we can assume as "real" developers who reads/writes on DC daily. But this touches only the English world.  And not all of them know about DC. 

My evaluation is 10,000-15,000 developers worldwide.

E.g. last the IT Planet contest in Russia this year gathered 2,400 participants for InterSystems contest (mostly students). Should we count students as developers? Today maybe not, but tomorrow...