How to get the Google Chat (Hangout) ID of a google authenticated user (oauth2)?

Question

I am working on xmpp client for google chat. I need the Google Talk ID which looks something like "[email protected]" of a user. Using oauth2, I am able to get the email id(gmail) and other profile information but I can't figure out how to get the Google Chat ID.

I know that I can use the email id in place of the Google Chat ID for all purposes. I need the Google Chat ID because I am using email ID as an identifier in my user table. Whenever a user receives a message in Google Chat (Hangouts), I am getting the from id as "[email protected]" . There's no way for me to check if I have a record of the sender in my user table. If I can retrieve the Google Chat ID when people authenticate with my client, I can store it in the user table and use it to match when a user receives messages.

Sending messages works fine because I have the email id of the target user and I can use that to send message.

Please suggest if it's possible to get the Google Chat ID

Answer 1

There is even other problem: you can send or receive messages from users you don't even know the email ID. Maybe rely on using Google Talk ID always instead of email ID for your user table can be a better option.

BTW I heard something about that Google is discontinuing Google Chat...