How to look up user information from Google GAIA ID? - php

Question

I've been working on a Hangouts.json parser for Google's Takeout service that takes all of the conversations, attachments, and miscellaneous information from the json file and populates a database with everything. I've finished everything but the only information the json file provides for who sent what is a GAIA ID that I've been able to figure out is the unique ID Google uses between their services. The problem is I don't know how to look up any other information about the user such as the name they identify with or their email.
I know most of the information is publicly available as you can take the GAIA ID and put it into a URL like: https://plus.google.com/u/0/#####################/about where the #'s are the GAIA ID. This page will reveal their screen name publicly. When a email address is unknown the same thing can be inferred by using: reply-######################profiles.google.com where this will also be able to be used to contact them.
Ideally I'd like to be able to look up a user's screen name without having to parse that public Google+ page at least but a true email would be great as well. So ideally I'd like an API or other resource to look up screen names and / or email info from a GAIA ID.

Answer 1

IMPORTANT UPDATE
March 2019: This answer is still getting up votes, however Google are withdrawing / have withdrawn the Google Plus API.
You will need an alternative solution as this will no longer apply.
Original Reply
Use the Google Plus API: https://developers.google.com/+/api/
I've not tested specifically with Hangouts (I never knew there was a Hongouts API!) but it returns details given IDs from other APIs.
You can test it out here: https://developers.google.com/apis-explorer/#p/plus/v1/plus.people.get to see what you'll get.

Answer 2

The Gaia ID may be obtained with the People API, by requesting the metadata in the personFields.
You may try it with the Google APIs Explorer (sample links are provided below).
For any of your contacts (provided he/she is a google user), using the people.connections/list resource :
People API - people.connections/list - personFields=names,metadata
(I have included the names value in the personFields for better illustration, though it is not required to retrieve the Gaia Id)
Sample output (1XXXXXXXXXXXXXXXXXXXX is the Gaia Id):
{
"connections": [
{
"resourceName": "people/c42",
"etag": "...",
"metadata": {
"sources": [
{
"type": "CONTACT",
...
},
{
"type": "PROFILE",
"id": "1XXXXXXXXXXXXXXXXXXXX",
...
"profileMetadata": {
"objectType": "PERSON",
"userTypes": [
"GOOGLE_USER"
]
}
}
....
],
"objectType": "PERSON"
}
"names": [
{
...
"displayName": "John Doe",
...
}
]
},
...
}
For yourself or any user using the people/get resource
People API - people/get - personFields=metadata
In the resourceName field :
use people/me to obtain your informations.
use the resourceName value previously retrieved in a people.connections.list request to retrieve another user informations
Sample output (1XXXXXXXXXXXXXXXXXXXX is the Gaia Id):
{
"resourceName": "people/...",
"etag": "....",
"metadata": {
"sources": [
{
"type": "PROFILE",
"id": "1XXXXXXXXXXXXXXXXXXXX",
"etag": "...",
"profileMetadata": {
"objectType": "PERSON",
"userTypes": [
"GOOGLE_USER"
]
}
...
},
...
],
"objectType": "PERSON"
}
}

Answer 3

Go to google chat.
create a chat with the person you want to find gaia id.
tag the person in the chat window
(#name of person)
right click the name, click "Inspect"
There you will find the ID
data-user-id="10xxxxxxxxxxxxxxxxxxx
#Name of person