Can we access GMAIL API using Service Account?

Question

I have a desktop application to read mail using GMAIL API over REST Interface. I want to use service account so that we can download the mails using domain setting and user

Answer 1

Here is a little bit of python 3.7:

from google.oauth2 import service_account
from googleapiclient.discovery import build

def setup_credentials():
    key_path = 'gmailsignatureproject-zzz.json'
    API_scopes =['https://www.googleapis.com/auth/gmail.settings.basic',
                 'https://www.googleapis.com/auth/gmail.settings.sharing']
    credentials = service_account.Credentials.from_service_account_file(key_path,scopes=API_scopes)
    return credentials


def test_setup_credentials():
    credentials = setup_credentials()
    assert credentials


def test_fetch_user_info():
    credentials = setup_credentials()
    credentials_delegated = credentials.with_subject("tim@vci.com.au")
    gmail_service = build("gmail","v1",credentials=credentials_delegated)
    addresses = gmail_service.users().settings().sendAs().list(userId='me').execute()
    assert gmail_service