SpotiApp

A local Shiny app to analyze, reorganize and back up your Spotify playlists.

What it does

Clustering

• Pick up to 2 of your playlists and load their tracks
• Group them with k-means (you choose 2–4 groups) or HDBSCAN (finds the number of groups itself) using track and artist features: popularity, duration, explicitness, release year, artist popularity and genre tags
• A genre weight slider controls how much genres drive the grouping
• Browse each cluster, compare them on a radar chart, download a cluster as CSV or save it as a new private playlist

Organize

• Two playlists side by side with track metadata (album, year, duration, popularity, genres, date added)
• Move or copy tracks between them. Changes stay pending (with Undo) until you confirm
• Confirm sends only the net changes to Spotify and refuses if a playlist was edited elsewhere in the meantime
• Every confirmed change is saved in a local history and can be reverted later, even after restarting the app. Tracks go back to their original positions
• If a playlist ends up empty, the app offers to delete it (reverting brings it back)

Backup

• Export any playlists as CSV, or all of them as a ZIP (one CSV per playlist)
• Each export also saves a local snapshot. Playlist history compares two snapshots and lists added and removed tracks

Stack

R, Shiny + bslib, httr2 (Spotify Web API, OAuth with PKCE), dplyr/tidyr/purrr, tidyclust + dbscan, plotly, DT, DuckDB (local history), renv.

Key decisions:

• No audio features endpoint: Spotify deprecated /v1/audio-features (403 on apps created after ~2024). Features come from /v1/artists (popularity, genres) and track metadata (duration, explicit, release year).
• Local only: the OAuth token is cached encrypted in your user cache directory, and history lives in spotify_app/spotiapp.duckdb. Both stay on your machine and out of git.

Setup

1. Spotify credentials

Go to developer.spotify.com, create an app, and copy the Client ID and Client Secret. Under the app settings, add this Redirect URI:

http://127.0.0.1:1410/

Create a .Renviron file in the project root (use .Renviron.example as reference):

SPOTIFY_CLIENT_ID=your_client_id
SPOTIFY_CLIENT_SECRET=your_client_secret
SPOTIFY_CLIENT_REDIRECT_URI=http://127.0.0.1:1410/

Restart your R session after saving.

2. Install dependencies

Open R in the project root (renv activates on its own) and run:

renv::restore()

The lockfile uses Posit Package Manager, so on Linux packages install as binaries.

3. Run the app

shiny::runApp("spotify_app")

The app opens at http://127.0.0.1:3838. Click Log in with Spotify (top right); the first time, a browser window asks you to authorize the app.