Integrating Gmail API into an Android application: How to proceed?

Other Questions Gmail
1

Hey everyone! I’m working on an Android app and I want to use the new Gmail API to get all emails from a user’s account. I’ve done some setup already:

  1. Registered my app in the Google Developers Console
  2. Added Google+ Sign-in to my app
  3. Included the Gmail API scope in the authorization

I’ve got a working GoogleApiClient object now. But when I try to access the Gmail API, I get a 401 Authentication error saying ‘Login required’. This is weird because the Google+ login worked fine and I can even get the user’s circles.

Here’s what I’m confused about:

  • How do I use the GoogleApiClient to make that HTTP request for listing emails?
  • Why am I getting an auth error even though Google+ login succeeded?

I’ve tried looking at the docs but I’m stuck. Any help would be awesome! Thanks!

2

I’ve been through this process recently, and I can tell you it’s a bit tricky. The key thing you’re missing is probably the proper authorization for Gmail-specific actions. Even though you’ve got Google+ working, Gmail needs its own permissions.

Here’s what worked for me:

Make sure you’re using the correct Gmail API scope. It should be ‘https://www.googleapis.com/auth/gmail.readonly’ for reading emails.

After you get your GoogleApiClient, you need to request a specific token for Gmail. Use GoogleAccountCredential.usingOAuth2() with the Gmail scope, then build a Gmail service with this credential.

Once you have the Gmail service, you can use it to make API calls. For example, to list messages:

List messages = service.users().messages().list(“me”).execute().getMessages();

This approach should solve your authentication issues. Just remember, the Gmail API has stricter security requirements than Google+, so you might need to jump through a few more hoops. Good luck with your project!

3

hey mate, i’ve worked with the gmail api before. sounds like ur missing the gmail-specific auth token. after google+ login, u need to request a separate token for gmail access. try using the GoogleAuthUtil.getToken() method with the gmail scope. that should solve ur auth issue. lmk if u need more help!

4

I encountered a similar issue when integrating the Gmail API into my Android app. The key is to ensure you’re using the correct scope for Gmail access. After obtaining the GoogleApiClient, you need to request an OAuth 2.0 token specifically for the Gmail API.

Try adding this scope to your GoogleSignInOptions:

‘https://www.googleapis.com/auth/gmail.readonly’

Then, use the GoogleSignInAccount to get the account name and request the token:

String accountName = account.getEmail();
String token = GoogleAuthUtil.getToken(context, accountName, GMAIL_SCOPES);

Once you have the token, include it in the Authorization header of your HTTP requests to the Gmail API. This should resolve the 401 error you’re experiencing.