I built my own Google Calendar Event Scheduler with FastAPI
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Hey Codemonkey!
I'm introducing a simple FastAPI-based application that allows users to schedule and manage events using the Google Calendar API. This app integrates Google OAuth for authentication, enabling event creation and retrieval from a user's Google Calendar.
Features
- Google OAuth2 for user authentication.
- Fetch upcoming events from the user's primary Google Calendar.
- Create new events on the user's Google Calendar.
- In-memory token storage for authenticated users (single-user session) to keep the project simple.
Project Structure
google-calendar-event-scheduler/
│
├── app/
│ ├── api/
│ │ ├── auth.py # Handles authentication routes
│ │ ├── events.py # Handles event-related routes
│ │ └── __init__.py # Imports FastAPI routes from different modules
│ ├── core/
│ │ ├── config.py # Configuration for environment variables and settings
│ │ └── auth_flow.py # Google OAuth flow setup and helper functions
│ ├── models/
│ │ ├── event.py # Pydantic models for request/response schemas
│ │ └── __init__.py # Imports all models
│ ├── services/
│ │ ├── calendar.py # Calendar service interactions
│ │ └── __init__.py
│ ├── __init__.py # Initialize FastAPI app
│ └── main.py # Entry point for the application
├── .env # Environment variables, ignored from git tracking
├── .env.example # Environment variables example
└── requirements.txt # Dependencies
Pre-requisites
Python 3.12
A Google Cloud project with Google Calendar API and OAuth credentials.
Virtual environment (venv)
Setting up Google OAuth
Go to the Google Cloud Console.
Create a project and enable the Google Calendar API.
Set-up OAuth 2.0 credentials: Authorized redirect URIs should match the one used in the .env file.
Download the OAuth client credentials and place them in your .env file.
Environment Variables
- Create a .env file in the root directory with the following contents same as .env.example file:
GOOGLE_CLIENT_ID=your-client-id
GOOGLE_CLIENT_SECRET=your-client-secret
GOOGLE_REDIRECT_URI=http://localhost:8000/auth/redirect
GOOGLE_SCOPES=https://www.googleapis.com/auth/calendar
Installation
Clone the repository:
git clone https://github.com/raselhasan111/google-calendar-event-scheduler.git
cd google-calendar-event-scheduler
Create and activate a virtual environment:
python3 -m venv venv
source venv/bin/activate # On Windows use `venv\Scripts\activate`
Install dependencies:
pip install -r requirements.txt
And set up your environment variables in .env (as shown above).
Running the Application
Start the FastAPI app using Uvicorn:
uvicorn app.main:app --reload
The app will be running at http://127.0.0.1:8000.
Endpoints
- Login with Google OAuth
Endpoint: /auth/login
Method: GET
Description: Redirects the user to Google's OAuth2 login page.
- Handle OAuth Redirect
Endpoint: /auth/redirect
Method: GET
Description: Handles the OAuth2 callback and saves the access token.
- Get Events
Endpoint: /events
Method: GET
Description: Fetches up to 10 upcoming events from the user's Google Calendar.
- Create Event
Endpoint: /events
Method: POST
Description: Creates a new event in the user's Google Calendar.
Sample Request:
{
"summary": "Project Kickoff Meeting",
"description": "Discussing the new project with the team.",
"start": {
"dateTime": "2024-10-15T09:00:00-07:00",
"timeZone": "America/Los_Angeles"
},
"end": {
"dateTime": "2024-10-15T10:00:00-07:00",
"timeZone": "America/Los_Angeles"
},
"location": "Google Meet",
"attendees": ["email@example.com"]
}
Open http://127.0.0.1:8000/docs to test endpoints with swagger.
Now it's your time to plug and play, happy coding!
Source Code: Github Repository
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Rasel Hasan
Rasel Hasan
Rasel Hasan is a recent CS graduate with a problem solving mindset, currently contributing to real world web engineering projects. He participated in 10+ onsite and 135+ online programming contests including ICPC and NCPC. He solved 1700+ data structures and algorithmic problems. He finds interest in learning and deep diving into web technologies.