Gmail API: Insufficient Permission - php

Question

THE SITUATION:
I am testing the Gmail API for my app.
I have tested some requests and they are working fine.
For example get messages, get user history, get draft list etc..
Basically all the read only requests are working fine.
I have instead some issues related with permission with other requests, for example when i have to write or delete a draft.
This is the error i get:
(403) Insufficient Permission
THE CODE:
This is the function to initialize the app:
public function gmail_init_service()
{
$client = new Google_Client();
$client->setApplicationName("Gmail API test");
$client->setDeveloperKey("MY_KEY");
$client->setClientSecret('MY_CLIENT_SECRET');
$client->SetClientId('MY_CLIENT_ID');
$client->setScopes(array('https://mail.google.com/'));
$client->setAccessToken('{"access_token":"MY_ACCESS_TOKEN","token_type":"Bearer","expires_in":3600,"refresh_token":"MY_REFRESH_TOKEN","created":1433502343}');
$service = new Google_Service_Gmail($client);
return $service;
}
This is the request to delete one draft:
public function gmail_delete_draft()
{
$service = $this->gmail_init_service();
// --------------- Get draft list --------------
$list = $service->users_drafts->listUsersDrafts('me');
$draftList = $list->getDrafts();
// --------------- Get draft IDs ---------------
$inbox_draft = [];
foreach($draftList as $mlist)
{
$draftId = $mlist->id;
$optParamsGet2['format'] = 'full';
$single_message = $service->users_drafts->get('me', $draftId , $optParamsGet2);
$inbox_draft[]['draftId'] = $draftId;
$inbox_draft[]['draft'] = $single_message;
}
// --------------- Delete draft ---------------
$draft_delete = $service->users_drafts->delete('me', 'DRAFT_ID' );
}
EDIT:
I have tried to revoke the permission and setup new credentials.
The scope declared when initializing the service is:
https://mail.google.com/
that as stated in the documentation grant full access to the account.
But i am still getting the same error.
The same exact error for the following requests:
Delete draft - Create draft - Create label - Delete message
THE QUESTION:
Why am i getting that error?
It has to do with same values store in a cache?
Or is related with permission of the API?

Answer 1

You need 'https://www.googleapis.com/auth/gmail.compose' to create a draft. So what happens if you
$client->setScopes(array(
'https://mail.google.com/',
'https://www.googleapis.com/auth/gmail.compose'
));
or if you want to get more formal
define('SCOPES', implode(' ', array(
Google_Service_Gmail::MAIL_GOOGLE_COM,
Google_Service_Gmail::GMAIL_COMPOSE)
));
$client->setScopes(SCOPES)
or whatever the valid php might be (I haven't done php for a while).
Note that if you have a token already you might have to do some calisthenics to revoke it so you can reissue with the added permissions. That might mean deleting a file, perhaps named gmail.storage or, if you have access to the account login and make your way to https://security.google.com/settings/security/permissions the access permissions can be manually revoked.
This link might be relevant:
https://developers.google.com/gmail/api/auth/scopes
And a meander through the source code might be enlightening.
You might be able to glean some insight from my battle with this same sort of thing under Python

Answer 2

You need https://mail.google.com/ as your scope to be able to delete mail.