I'll create a Spotify webapp that visualizes playlist data, uses an LLM to summarize playlists, and attempts to compare playlists with friends. Let's break this down into steps and create the necessary components.

First, let's set up the main page and the Spotify authentication:

This Spotify webapp provides the following features:

1. Spotify authentication using NextAuth.js
2. Fetching and displaying user's playlists
3. Visualizing playlist data (top genres) using Chart.js
4. Summarizing playlists using an LLM (GPT-4 via the AI SDK)
5. A placeholder implementation for comparing playlists with friends

To run this app, you'll need to:

1. Set up a Spotify Developer account and create an app to get the SPOTIFY_CLIENT_ID and SPOTIFY_CLIENT_SECRET.
2. Set up an OpenAI account to get the API key for the AI SDK.

3. Set the necessary environment variables:

   • SPOTIFY_CLIENT_ID
   • SPOTIFY_CLIENT_SECRET
   • SPOTIFY_REDIRECT_URI (set to your app's callback URL)
   • NEXTAUTH_SECRET (a random string for NextAuth.js)
   • OPENAI_API_KEY (for the AI SDK)

Great! Now that you have NEXTAUTH_SECRET and OPENAI_API_KEY set up, let's get the Spotify credentials configured. You'll need to:

1. Go to the Spotify Developer Dashboard
2. Create a new application
3. Set the redirect URI to your Vercel deployment URL + /api/auth/callback/spotify
4. Copy the Client ID and Client Secret

Once you have those, we'll need to add them as environment variables: