There is pdf Make which has a nice declarative API to describe PDFs. And works client side. Worth a try!
Have a look on ZetPDF, this might help you as this is an SDK for .net and alike.
If you are looking to do PDF generation in client side, you can give a look at here :
TheSheriff
Co-Founder, Founder, Entrepreneur & Problem Solver
mozilla.github.io/pdf.js Mozilla's official project