CC BY-SA – Do I need to open source my app if I don’t really distribute it?

Question

I started developing a commercial web application that uses spaCy – a MIT-licensed library for natural language processing. In order to use this library, one needs to initialize a processing pipeline by pointing to one of the language models – data files distributed under the CC BY-SA-3.0 license. The model, in an unaltered form, gets loaded and then the application interacts with the library through its API, not directly with the model.

I’ve read the license (CC BY-SA-3.0) but it’s hard for me to determine whether my application should be considered a derivative work or not. On the one hand the application only indirectly uses the model (doesn’t improve/modify it in any way), but on the other hand, such a model is indispensable for the application to work.

But what’s crucial for me is this. Let’s assume that my application constitutes a derivative work. Does this mean that I have to release the application’s source code under the CC BY-SA-3.0 license, even though the application runs only on my servers and users can only interact with it through a computer network? Does it work similarly to the AGPL?

I really appreciate any help you can provide.

Answer 1

To answer the last question first, interaction with a program using a remote connection is not considered distribution of the program and will not invoke the terms of the license unless the license explicitly states otherwise.
To my knowledge, only the AGPL has such terms. As such terms are specifically designed for software, the CC-BY-SA licence won't have them, as it is not recommended for software.

With regards to the other question, if the software can load any correctly formed language file and not just the CC-BY-SA ones, then it can be seen that the software can't be a derived work of the language file.
In general, a program and the files it reads are considered to be independent works for copyright.