Session , invitation-only flow and/or social logins

Hello,

The following is required for our app. I was wondering how to implement this with auth0

Usecase: master_user creates the account with our app and creates his/her own chat session. Later for the same chat session he/she can invite other users to collaborate.

  1. After master_user creating session with our app he/she can invite of our app through emails/text message /whats app etc…

  2. The invitees let say user1, user2 etc…are the who got email invitation link through following means
    1. User1 got through email
    2. User2 got through text message

  3. Invitees needs download our app first and after downloading app the screen should direct to sign up page.

  4. Now, when user1/user2 when they arrive at the signup/registration they are free to choose any social sign-up methods / email / phone number. Let say
    1. User1 got invitation through email is instead using social sign-up ( FB, Apple, Google etc…)
    2. User2 got through text message is instead using email for sign-up

  5. Once user1/user2 sign up is done they should be automatically added to the chat session sent by the main_user.

Questions:
1. How to uniquely identify the user1 / user2 when they don’t use original method of invitation and
2. how to automatically add invitees to the master_user session whey they signup when they sign-up
3. Since, app downloading and sign-up are both orthogonal steps how to retain invitation that is sent my the main_user.