Gmail API Push Notifications gives Error 403

Question

I am trying to get push notifications regarding all the new inbox messages I receive in my email. I have configured the pubsub client as mentioned in the pubsub doc. Following is the code:

import httplib2

from apiclient import discovery
from oauth2client import client as oauth2client
from lib.common.models.main.users import User

from oauth2client.client import SignedJwtAssertionCredentials,\
    AccessTokenRefreshError

PUBSUB_SCOPES = ['https://www.googleapis.com/auth/pubsub']

def create_pubsub_client(http=None):
    credentials = oauth2client.GoogleCredentials.get_application_default()
    if credentials.create_scoped_required():
        credentials = credentials.create_scoped(PUBSUB_SCOPES)
    if not http:
        http = httplib2.Http()
    credentials.authorize(http)

    return discovery.build('pubsub', 'v1', http=http)

pubsub = create_pubsub_client()

topic = 'projects/<project-name>/topics/<Topic-name>'
policy = {
  'policy': {
    'bindings': [{
      'role': 'roles/pubsub.publisher',
      'members': ['serviceAccount:<my-service-account>'],
    }],
  }
}
resp = pubsub.projects().topics().setIamPolicy(resource=topic, body=policy).execute()

request = {
  'labelIds': ['INBOX'],
  'topicName': 'projects/<project-name>/topics/<Topic-name>'
}

f = file('link-to.p12', 'rb')
key = f.read()
f.close()

credentials = SignedJwtAssertionCredentials(
    'service-account-email',
    key,
    scope='https://mail.google.com/',
)

user = User.query.filter(User.id == 143).first()
accesskey = user.get_access_key(True)
credentials.access_token = accesskey['key']

service = discovery.build('gmail','v1',credentials=credentials)
service.users().watch(userId='me', body=request).execute()

When I run the above Program, I encounter the following error:

Traceback (most recent call last): File "/home/kmittal/workspace/engine/workers/newPubSubClient.py", line 82, in service.users().watch(userId='me', body=request).execute() File "/usr/local/lib/python2.7/dist-packages/oauth2client/util.py", line 135, in positional_wrapper return wrapped(*args, **kwargs) File "/usr/local/lib/python2.7/dist-packages/googleapiclient/http.py", line 723, in execute raise HttpError(resp, content, uri=self.uri) googleapiclient.errors.HttpError: https://www.googleapis.com/gmail/v1/users/me/watch?alt=json returned "Invalid topicName does not match projects/SOME_ANOTHER_PROJECT/topics/*">

Answer 1

As per this other answer , it looks like you can only create a watch for topics that are part of your own project, not another project. Thedocumentation seems to back this up as it implies you must specify myproject (your own project ID):

The topic name can be any name you choose under your project (ie matching projects/myproject/topics/*, where myproject is the Project ID listed for your project in the Google Developers Console).