Flask Gmail OAuth

This is a simple Flask application that uses OAuth 2.0 for Google login and Gmail API to send emails. The application includes three main pages: the email form, the email preview, and a confirmation page upon successful email sending.

Project Structure

FLASK MAILER TEST
│
├── templates
│   ├── index.html
│   ├── preview.html
│   └── sent.html
│
├── .env
├── .gitignore
├── app.py
└── requirements.txt

Getting Started

Prerequisites

• Python 3.x
• A Google Cloud project with OAuth 2.0 credentials

Installation

1. Clone the repository

git clone https://github.com/marketcalls/flask-gmail-oauth.git
cd flask-gmail-oauth

2. Create and activate a virtual environment

python3 -m venv venv
source venv/bin/activate  # On Windows use `venv\Scripts\activate`

3. Install the dependencies

pip install -r requirements.txt

4. Set up environment variables

Create a .env file in the root directory with the following content:

SECRET_KEY=your_secret_key
MAIL_DEFAULT_SENDER=your_email@gmail.com
GOOGLE_CLIENT_ID=your_google_client_id
GOOGLE_CLIENT_SECRET=your_google_client_secret
OAUTH_ACCESS_TOKEN_URL=https://oauth2.googleapis.com/token
OAUTH_AUTHORIZE_URL=https://accounts.google.com/o/oauth2/auth
OAUTH_SCOPE=openid email https://www.googleapis.com/auth/gmail.send https://www.googleapis.com/auth/userinfo.email
OAUTH_USERINFO_ENDPOINT=https://www.googleapis.com/oauth2/v3/userinfo
OAUTH_JWKS_URI=https://www.googleapis.com/oauth2/v3/certs
GMAIL_API_SEND_URL=https://www.googleapis.com/gmail/v1/users/me/messages/send

Setting Up Google Cloud Project

1. Create a new project in Google Cloud Console

   • Go to the Google Cloud Console
   • Click on the project dropdown at the top left and select "New Project"
   • Name your project and click "Create"

2. Enable Gmail API

   • Navigate to the Gmail API
   • Click "Enable"

3. Create OAuth 2.0 credentials

   • Go to the Credentials page
   • Click on "Create Credentials" and select "OAuth 2.0 Client IDs"
   • Set the "Application type" to "Web application"
   • Add http://127.0.0.1:5000 to "Authorized JavaScript origins"
   • Add http://127.0.0.1:5000/login/authorized to "Authorized redirect URIs"
   • Click "Create"
   • Copy the "Client ID" and "Client Secret" to your .env file

Test Email IDs in Google Cloud Console

You can use the test email IDs for testing the application in the oAuth Consent screen then scroll down to the Test users section and add the test users

Usage

1. Run the Flask application

python app.py

2. Access the application

Open your web browser and go to http://127.0.0.1:5000/login to login to application using gmail and http://127.0.0.1:5000/ to send email

License

This project is licensed under the MIT License.