Hey there, it seems that the Web-API might be a good fit for what you’re looking for. It allows you to query and change various data of your minecraft server through JSON REST calls, and also comes with a handy admin panel (which you can turn off if you don’t need it) where you can manage your server and see what the API is capable of 
The documentation is rather extensive aswell, which you can view here to get an idea of all the routes the Web-API offers.
(DISCLAIMER: I am the developer of Web-API)