Have you written this library or is an already existent one? Also can be used offline but maybe provide an easy way to download it so can run it locally or host it on own server? (Unless of course there's a plan to monetize this.)
It is a very small PDF library that I have written myself in C++. I am planning to release the source, but haven't decided on the license yet. It is very limited in features compared to the whole PDF specification but I am planning to keep adding to it.