[keycloak-user] Custom social identity provider in Keycloak 2.5.1

Hello Keycloak users, As everyone know keycloak provider with many social IDP providers login method such as facebook, google, twiiter, etc. But in my case, I have to integrate a custom social IDP in keycloak. Can anyone help me as to how can I start with the implementation of Custom Social IDP in keycloak. Thanks in advance !!!! Regards, Haseb