I am currently programming a mobile app that is not under the GPL.
However, the mobile app correspond with a website that is under GPL Version 2 or higher.
In my case the mobiel app send request via POST-method and then fetches data that is displayed as json on the website.

(Would the license be AGPL, I'm pretty sure that the mobile app also would be under the AGPL.)

How is it in my case?

  • It's prudent to note that facts are not subject to copyright, open source, or otherwise.
    – tuskiomi
    Jun 28, 2021 at 12:45
  • If this was the case, that would mean that everybody (you, me, ...) who may happen to browse random GPL-licensed websites, would need to use GPL-licensed browsers. That would make the FSF very busy right now...
    – dim
    Jun 28, 2021 at 14:31

1 Answer 1


The license of an application and the license of data that application produces can be independent, and are only interrelated if the data includes executable code from the executable itself:

Is there some way that I can GPL the output people get from use of my program? For example, if my program is used to develop hardware designs, can I require that these designs must be free?

In general this is legally impossible; copyright law does not give you any say in the use of the output people make from their data using your program. If the user uses your program to enter or convert her own data, the copyright on the output belongs to her, not you. More generally, when a program translates its input into some other form, the copyright status of the output inherits that of the input it was generated from.

So the only way you have a say in the use of the output is if substantial parts of the output are copied (more or less) from text in your program. For instance, part of the output of Bison ... would be covered by the GNU GPL, if we had not made an exception in this specific case.

However, if the data served by the application is pre-existing (i.e., it was not directly created by the application) it may happen to be under a copyright license itself (e.g., consider an application that serves the text of user-submitted copyrighted stories).

In your case, a requesting application that receives some data from a web app is almost certainly not a derivative of the serving web app, not a derivative of the served data, either.

Even if the web app were AGPL-licensed, that would only impose requirements for code that is part of the server-side application, not clients that interact with it; generally, clients under any license may interact with an AGPL-licensed service, because they are separate works.

  • 1
    As an additonal observation: Presume for a moment that accessing data from a web-site WOULD automatically transfer the license status of the data to the retrieving application. What license status would any web-browser then have? And applications like curl, wget and download-managers? After all: They all retrieve data from web-sites with all sorts of (and possibly conflicting) license status all the time. It would be an impossible mess.
    – Tonny
    Jun 28, 2021 at 7:38
  • So even if I edit, manipulate or otherwise use the data in the web app and make it available again to the mobile app, this edition is not subject to the GPL. I also get data from the web app such as the time or other content and images created via the web app that were uploaded and processed via the web app. In this case, too, the GPL does not apply to the mobile app. Only if the web app would actually send snippets of code from the GPL application to the mobile app and this would be executed in the mobile app, the mobile app be under GPL. Jun 28, 2021 at 9:22
  • @Vincent And even then, it would matter more how your application's code relies on the downloaded code. On one extreme, if the downloaded data is a Python script and your app is is Python interpreter, the act of accessing input from the Web does not make your interpreter derivative of that input. It is difficult to imagine a situation in which downloading and executing code from the Web makes your app derivative of that code.
    – apsillers
    Jun 28, 2021 at 10:59
  • @apsillers If users of the web app upload images to this, the images are also not under the GPL, right? Because they have nothing to do with the GPL code. Jun 28, 2021 at 11:37

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