hey guys, i’m developing a web application to connect to ari, is it necessary to include in code the authentication to access to it?
Best regards
If you want it to directly connect to ARI, yes. Take note though that ARI is made to connect from trusted applications, not from a web browser for example.
do you know the code to it on c#?
I have never used C# and the project doesn’t provide a library for it.
but it is compatible right?
ARI provides a REST interface, provided the language has mechanisms to do HTTP requests and websockets it can be used. Asterisk doesn’t care what language is used on the other side.
ok, thank you very much 
If you’re just starting out there are a few community supported 3rd party libraries and frameworks out there that might help. Some of those are listed here. And there is one in C#.
Also I highly recommend reading through the Asterisk REST Interface documentation and its child pages.