I'm trying to figure out if GPLv3 copyleft is triggered for the following scenario:
A company has a backend service written in a dynamically typed programming language. The service has a bunch of dependencies, including a module under GPLv3 license. The GPLv3 module is linked dynamically into the backend service's main program. The service exposes some public API endpoints, exchanging JSON-based data. The company also has a mobile client distributed via major digital distribution platforms. The mobile clients use the backend's API endpoints to operate.
My questions are the following:
- Can the backend service the company is running be considered a private copy of GPL covered work so that copyleft isn't triggered in this case and the company doesn't have to convey (distribute) a source code of its service to the public?
- Can be the backend service program and the mobile client considered as two independent programs (taking into account that they are exchanging JSON data)?
- Any real court cases supporting the answers for 1 and 2? (I do understand that jurisdiction may matter here)
- How AGPLv3 for the dependency module would change the outcome?
My understanding is that:
a. Backend service is a modified version of GPL covered work (dynamically linking considered as modification, see https://www.gnu.org/licenses/gpl-faq.html#GPLStaticVsDynamic)
b. Backend service isn't conveyed/distributed, because the interaction is done over the network (see https://www.gnu.org/licenses/gpl-faq.html#UnreleasedMods)
c. Mobile client and the backend are considered two separate, independent programs, because the interaction is based on simple JSON data, with NO source code, code generation, complex internal data structures involved in exchange (see https://www.gnu.org/licenses/gpl-faq.html#MereAggregation).
So the copyleft isn't triggered in this case, the company has a right to run its software on the backend as a private copy. The copyleft would trigger if the backend service dependency would be under GNU Affero General Public License.
But I am not a lawyer, so I am not sure. Any help is highly appreciated!