Twitch OAuth FastAPI Backend

This is a FastAPI-based backend that authenticates users via Twitch's OAuth and fetches their user information. The backend uses the twitch-api to retrieve user details like email, username, and profile image.

Features

• Twitch OAuth Authentication
• Fetches user profile data: username, display name, email, etc.
• No database needed, only access to Twitch API via OAuth

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Prerequisites

Before you start, you need:

• Python 3.7+
• Twitch Developer Account
  Create an application in the Twitch Developer Console to get a Client ID and Client Secret.

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Installation and Setup

1. Clone the Repository

Clone this repository to your local machine:

git clone https://github.com/your-username/twitch-fastapi-backend.git
cd twitch-fastapi-backend

2. Install Dependencies

Make sure you have pipenv installed. If not, you can install it with:

pip install pipenv

Then, install the required dependencies:

pipenv install

3. Set Up Environment Variables

Create a .env file in the root directory of the project, and fill in the following details:

TWITCH_CLIENT_ID=your_actual_twitch_client_id
TWITCH_CLIENT_SECRET=your_actual_twitch_client_secret
TWITCH_REDIRECT_URI=http://localhost:8000/auth/callback
TWITCH_SCOPES=user:read:email

You can get your Client ID and Client Secret from the Twitch Developer Console.

4. Start the Development Server

Now, run the FastAPI development server:

pipenv run uvicorn main:app --reload

The app will be running on http://localhost:8000.

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Usage

1. Authenticate with Twitch

Visit the following URL in your browser to initiate the OAuth login flow:

http://localhost:8000/auth/login

You will be redirected to Twitch’s login page. After successfully logging in and authorizing your app, Twitch will redirect you back to http://localhost:8000/auth/callback?code=....

2. View User Data

After the authentication is complete, the app will exchange the code for an access token and fetch your user data from Twitch. This will be displayed in your browser as a JSON response containing your user info like username, display name, email, and profile image.

Example Response:

{
    "access_token": "your_access_token_here",
    "user_info": {
        "data": [
            {
                "id": "12345678",
                "login": "your_username",
                "display_name": "YourDisplayName",
                "email": "your@email.com",
                "profile_image_url": "https://static-cdn.jtvnw.net/jtv_user_pictures/...",
                "description": "This is my Twitch bio!",
                "view_count": 1000
            }
        ]
    }
}

3. Check User Data in Console

You can also see the user data printed in the server logs (in your terminal) as the print() statement inside get_twitch_user_info function will show the data.

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Testing the Application

To test the application, follow these steps:

1. Start the development server using pipenv run uvicorn main:app --reload.
2. Visit http://localhost:8000/auth/login in your browser to authenticate with Twitch.
3. After successful login and redirect, you should see your user data returned as a JSON response.

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Troubleshooting

• Invalid Client ID / Client Secret: Make sure the TWITCH_CLIENT_ID and TWITCH_CLIENT_SECRET in the .env file match the ones in the Twitch Developer Console. Restart the server after editing .env.
• redirect_mismatch error: Ensure the redirect_uri in your .env matches exactly with the one in the Twitch Developer Console's OAuth settings.
• Access Token Issues: If you encounter errors related to the access token, try regenerating the Client Secret in the Twitch Developer Console and update it in your .env file.

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