Can't log in with Spotify when running locally

[zkornbluth]

Describe the bug
Clicking 'Log In with Spotify' button throws errors when running locally

To Reproduce
Steps to reproduce the behavior:

1. Follow the "Install and Run" instructions in the README
2. Open localhost:3000 and click 'Log In with Spotify'
3. You'll see these errors:

Expected behavior
Should be able to log in like you are on https://spotify-dedup.com/

Desktop:

• OS: MacOS Sequoia 15.6.1
• Browser: Chrome
• Version 140.0.7339.185

[need4swede]

@zkornbluth

Go to https://developer.spotify.com/dashboard

1. Log in with your Spotify account
2. Click "Create app"
3. Fill in the form:

• Name, Description, etc.
• Redirect URI: http://127.0.0.1:3000/callback
• API/SDKs: Check "Web API"
• Accept the terms of service

4. Click "Save"

On your app's dashboard, copy the Client ID
Click "Show Client Secret" and copy the Client Secret
Create a .env.local file in the project root:

NEXT_PUBLIC_SPOTIFY_CLIENT_ID=your_client_id_here
NEXT_PUBLIC_REDIRECT_URI=http://127.0.0.1:3000/callback
SPOTIFY_CLIENT_SECRET=your_client_secret_here

Replace:

• your_client_id_here with your actual Client ID
• your_client_secret_here with your actual Client Secret

Start the Development Server via pnpm dev
Open your browser and go to: http://127.0.0.1:3000
Important: Use 127.0.0.1, NOT localhost

[zkornbluth]

Thanks, that worked.

Closing. Might be worth adding these instructions to the README or a Contributing document.

[need4swede]

@zkornbluth

Done: #184