Authenticate with the Google Calendar API without Oauth Consent Screen (Python)

15 Feb 2023

Working on my Calendar script in Pyton !projects/calendee, I was faced with the token expiring every 3-4 hours, thus requiring a new manual authentication with consent screen to generate a new token.

It appears having an "always-on" token is not as simple as it should be.

Solution here was to:

• create Service account & download Service key as '.json' file, as per:

Google Calendar API in Your Application without Oauth Consent Screen

medium.com

https://medium.com/@ArchTaqi/google-calendar-api-in-your-application-without-oauth-consent-screen-4fcc1f8eb380

• apply Domain Wide Delegation to the Service account, as per:

Control API access with domain-wide delegation - Google Workspace Admin Help

google.com

https://support.google.com/a/answer/162106?product_name=UnuFlow&hl=en&visit_id=638120857399575487-3089946761&rd=1&src=supportwidget0&hl=en#zippy=%2Cbefore-you-begin%2Cset-up-domain-wide-delegation-for-a-client

• use following code:

from google.oauth2 import service_account

SCOPES = ['https://www.googleapis.com/auth/calendar']
credentials = service_account.Credentials.from_service_account_file(token, scopes=SCOPES)
creds = credentials.with_subject(calendar_id)
service = build('calendar', 'v3', credentials=creds)

where token is the path to the Service key file, and calendar_id is the email address of the Google Calendar.