How can I overcome Gmail API's HttpError 403 due to insufficient permissions in Python?

Encountering a permission error with Gmail API when sending an email in Python. Revised code sample:

import base64
from email.mime.text import MIMEText

def compose_email(sender, recipient, subject_text, body_text):
    msg = MIMEText(body_text)
    msg['From'] = sender
    msg['To'] = recipient
    msg['Subject'] = subject_text
    return {'data': base64.urlsafe_b64encode(msg.as_bytes()).decode()}

print(compose_email('[email protected]', '[email protected]', 'Hello', 'Test message'))

Any suggestions on fixing the credentials file issue on Windows?

I faced a similar issue when trying to use the Gmail API on a Windows setup. After spending hours combing through the documentation, I discovered that my problem wasn’t the code at all but the developer credentials. I had to ensure that the OAuth2 token included the correct scopes for the operations I was performing, and I needed to regenerate the refresh token with those permissions. What ultimately helped was going back to the Google Cloud Console and double-checking every setting linked to the API and associated service account.

I encountered a similar problem when developing my application. I discovered that the key was to carefully review the scopes authorized during the OAuth process. In my case, the issue was resolved by including the specific scope required for sending emails, which I initially overlooked when setting up the credentials in the Google Cloud Console. Additionally, verifying the file paths and ensuring the credentials file was accessible on Windows helped. Reviewing the Google documentation around the API’s requirements was essential in confirming that all necessary permissions were properly configured.

hey, i had a similar issue. re-check your oauth scopes in the google console and regen your token - sometimes windows causes file permission snags. hope this helps!