No "colorId" field returned in the Event object with the Google calendar api v3

I'm trying to just query a list of my calendar events for any given calendar using the v3 calendar api, an api key, and the browser fetch (or postman). I created a test calendar "Test Calendar 2", made it public, made an event, added a color to it, and made an api key on the google console.

Using this get url: https://www.googleapis.com/calendar/v3/calendars/CALENDAR_ID/events?key=MY_API_KEY, I get back a list of events like so:

{
    "kind": "calendar#events",
    "etag": "\"_\"",
    "summary": "Test Calendar 2",
    "description": "",
    "updated": "2024-04-06T04:47:30.237Z",
    "timeZone": "America/Los_Angeles",
    "accessRole": "reader",
    "defaultReminders": [],
    "nextSyncToken": "_==",
    "items": [
        {
            "kind": "calendar#event",
            "etag": "\"_\"",
            "id": "_",
            "status": "confirmed",
            "htmlLink": "https://www.google.com/calendar/event?eid=_",
            "created": "2024-04-05T04:12:13.000Z",
            "updated": "2024-04-06T03:34:03.072Z",
            "summary": "Hello",
            "description": "Description",
            "creator": {
                "email": "_@gmail.com"
            },
            "organizer": {
                "email": "_@group.calendar.google.com",
                "displayName": "Test Calendar 2",
                "self": true
            },
            "start": {
                "dateTime": "2024-04-01T19:00:00-07:00",
                "timeZone": "America/Los_Angeles"
            },
            "end": {
                "dateTime": "2024-04-01T20:00:00-07:00",
                "timeZone": "America/Los_Angeles"
            },
            "visibility": "public",
            "iCalUID": "_@google.com",
            "sequence": 0,
            "eventType": "default"
        }
    ]
}

However a bunch of properties from the Event object are missing (most importantly colorId). As described here: https://developers.google.com/calendar/api/v3/reference/events#resource

What am i missing? Is this field somehow restricted or can i get this to work?

Reading lots of mixed info about the colorId field online. I read that the colorId field may be undefined if the event only has its default color. But i updated it multiple times and it doesn't seem to return anything.

Solution

The problem is that colorId is now a private property of a Google Calendar event. To access this field, you need to follow these steps.

1. Create OAuth

Go to the Google Calendar API section and click Create Credentials (OAuth Client ID) in the Credentials section.
In the Scopes section, add .../auth/calendar.events.
In the Application Type section, select Desktop App.
Download your JSON file with credentials.

2. Perform Authentication (Python)

Create a new Python project and install the dependencies with:

pip install --upgrade google-api-python-client google-auth-httplib2 google-auth-oauthlib

Add your downloaded JSON file to the root of the project and name it credentials.json.
Add following code to main.py file


   from google.oauth2.credentials import Credentials
   from google_auth_oauthlib.flow import InstalledAppFlow
   from google.auth.transport.requests import Request
   import os
   import json
   
   # The required OAuth2 scopes for accessing Google Calendar
   SCOPES = ['https://www.googleapis.com/auth/calendar']
   
   
   def get_credentials():
       creds = None
       # The file where the access and refresh tokens are stored after the first run
       token_file = 'token.json'
   
       if os.path.exists(token_file):
           creds = Credentials.from_authorized_user_file(token_file, SCOPES)
       # If there are no valid credentials, initiate the OAuth flow
       if not creds or not creds.valid:
           if creds and creds.expired and creds.refresh_token:
               creds.refresh(Request())
           else:
               flow = InstalledAppFlow.from_client_secrets_file(
                   'credentials.json', SCOPES)  # Use the credentials.json file that contains your client_id and secret
               creds = flow.run_local_server(port=0)
           # Save the credentials for the next run
           with open(token_file, 'w') as token:
               token.write(creds.to_json())
   
       return creds
   
   
   if __name__ == '__main__':
       get_credentials()
       print("OAuth flow completed, token saved to 'token.json'")

Run the script:

python main.py

You will get a token.json file.

3. Use the Token

Instead of using key={api_key} in your Google Calendar API requests, use the token from the token.json file.
The token should be passed in the request header as:

Authorization: Bearer {token}

Additional:

To refresh the token, use the following request (the data should be taken from token.json):

    POST https://oauth2.googleapis.com/token
    Content-Type: application/x-www-form-urlencoded
    
    client_id={your_client_id}&
    client_secret={your_client_secret}&
    refresh_token={your_refresh_token}&
    grant_type=refresh_token