Safely storing an application's API keys

[Jean-Baptiste Mardelle]

Hi all,

For Kdenlive, we are planning to expand the use of online services to download 
ambiance music or videos for use in personal projects. To this purpose, most 
online services provide us an API key that is used to identify our app 
(Kdenlive) when querying their API.

Does anyone have experience / advice on how to protect these API keys so that 
they are not publicly available ? Is there any KDE online service or framework 
helping to achieve that ?

Thanks in advance for your help,

Jean-Baptiste Mardelle