This does just seem like a worse version of knockout. In knockout (with typescript annotations), the equivalent would be: let count = Knockout.Observable<

This does just seem like a worse version of knockout. In knockout (with typescript annotations), the equivalent would be: let count = Knockout.Observable<number>(0); And it's then much clearer when you want to access the value of the observable with count() or update it with count(1234) or count(x => x+1 ). ( I may have hallucinated the ability to pass a function to the observable ).