Web Api in asp.net

Question

How to create web api user specification in c# with app id and secret key. For e.g Facebook provide a api key and i will get all info a facebook account. 

 

This type app key how to make a web api code in asp.net web api.

 

I wiil create a project using api and ajax.

 

any solutin provide for me.

 

Thanx.