View source for Identity Service

== Introduction ==
The LFS Identity Service -based on Oauth2- allows you to integrate LFS user authentication into your own website and / or use the LFS API. Both purposes are often used together; your website can authenticate an LFS user visiting your own website to perform actions on your website, on behalf of the LFS user. These actions are performed using the LFS API. Though you can also use the LFS API alone via (back end) scripts, to fetch and / or update information related to your own LFS account.

You can find many explanations and further details about Oauth2 on the internet. A good introduction for example is the one from [https://www.digitalocean.com/community/tutorials/an-introduction-to-oauth-2 Digital Ocean].

== The Application ==
In order to use the LFS Identity Service, you must always register a so called Application. An Application is a record of your website that will perform LFS User authentications. Though registration of an Application is also required if you only want to use the LFS API in your (back end) scripts.

You must have at least one Application, but it is possible to register multiple Applications used for different purposes.

You can register your Applications at https://www.lfs.net/account/api

An Application is always required for Oauth2 authentications, one for each [[Identity_Service#Authentication_Flows|grant type (or flow)]] you will be using.

An Application must have a name and one redirect uri pointing to a callback endpoint on your website where authenticated users will return to after authentication. A redirect uri is also required even if you only use the LFS API for your own (back end) purposes. In that case you can enter a fictional redirect uri.

After Application registration you will receive a Client ID and a Client Secret that you must write down, in order to perform Identity Authentications later on.

== Authentication Grant Types ==
There are 2 authorization grant types that can be used. Which you should use depends on your use case:

* '''Authorization Code Grant with Proof Key for Code Exchange (PKCE)''', often used with [https://en.wikipedia.org/wiki/Single-page_application Single Page Applications]
* '''Client Credentials Grant''', used with back end scripts


=== Single Page Applications ===
For this purpose you should use the Authorization Code Grant with PKCE.

How does that work?

... stuffs here ...

=== Back End Scripting ===
For this purpose you should use the Client Credentials Grant.

How does that work?

... stuffs here ...

== Usage Examples ==
examples (are these needed? Maybe the grant explanations above should be enough - I don't think I should start providing actual code examples here - there are plenty available out on the nets.)

=== Single Page Applications ===
example here

=== Back End Scripting ===
example here