Glass wont block ‘sunlight’ for farming.
But, as it stands, the rule will be ‘vertical direct sunlight (ignoring glass)’ because we dont want the cost of doing full lighting of chunks on the server the way the client does. That could change in future (I hope so too), but isn’t a small amount of work to be able to have full lighting server-side in a cheap enough way that wont require us to end up reducing creatures/playercounts as a result