How to work with Visual studio Team Services Oauth Model and what is the purpose of Azure - azure

Question

I'm working with Visual Studio Online, and trying to use work with Oauth, which will allow me to use RESTFUL API of VSTS in my APP. How can I work. Please give a detailed answer, I'm confused.
One more thing is, while registering App in VSTS, there are two fields Application Website and Authorization Callback URL, which are making me more confused, what is the purpose of these two fields while registering App for Oauth.

Answer 1

First go read some documentation on Oauth and how it works.
On a high level, how does OAuth 2 work?
Then go read the documentation, which includes code examples, for VSO.
https://www.visualstudio.com/en-us/integrate/api/overview
Once you run into a specific issue, ask your question here with examples of what you tried.

Answer 2

i tried to use app for OAuth on my site. Got 400 Bad request on Visual Studio Online site everytime when code executed (user redirected to next URL from sample app):
return String.Format("{0}?client_id={1}&response_type=Assertion&state={2}&scope={3}&redirect_uri={4}",
ConfigurationManager.AppSettings["AuthUrl"],
ConfigurationManager.AppSettings["AppId"],
"state",
ConfigurationManager.AppSettings["Scope"],
ConfigurationManager.AppSettings["CallbackUrl"]
);
What`s wrong? Is there is some limitation for values in App registration page above?