authenticate_gmail.py

import os
from google_auth_oauthlib.flow import InstalledAppFlow

# Gmail API scope
SCOPES = [
    "https://mail.google.com/"
]

def run_authentication():
    print("Starting Google OAuth Authentication Flow...")

    if not os.path.exists("credentials.json"):
        print("ERROR: Please place your 'credentials.json' file in this folder first!")
        return

    flow = InstalledAppFlow.from_client_secrets_file(
        "credentials.json",
        SCOPES
    )

    creds = flow.run_local_server(port=8080)

    with open("token.json", "w") as token_file:
        token_file.write(creds.to_json())

    print("\nSUCCESS: 'token.json' has been created successfully!")

if __name__ == "__main__":
    run_authentication()