Stage Coach

Discover which artists to see at a music festival based on what you already listen to.

Paste a festival lineup URL, connect Spotify, and Stage Coach scrapes the lineup, scores every act against your listening history, and builds you a Spotify playlist of the best matches — a mix of artists you follow and new ones worth checking out.

How it works

Step	What happens
1. Lineup	You paste a festival lineup URL. A headless Chromium (Playwright) loads the page, and Claude extracts the festival name and the full artist list from the page text.
2. Tastes	You connect Spotify via OAuth. Stage Coach reads your top artists (short + medium term) and top tracks.
3. Match	Each festival artist is looked up on Spotify and given an affinity score. The top ~30 are shown, ranked.
4. Recommendations	A public Spotify playlist is created with 3 tracks per artist and the link handed back to you.

Scoring

Each festival artist accumulates points:

Signal	Points
In your short-term top artists	+100
In your medium-term top artists	+60
Appears on one of your top tracks	+40
Per shared genre with your taste profile	+5

Tracks are drawn first from songs already in your history (where the artist is primary), then filled from the artist's Spotify catalogue. URIs are de-duplicated across the whole playlist.

Stack

• Backend — FastAPI, spotipy, Anthropic SDK
• Frontend — single-page, vanilla JS + Alpine.js + Tailwind (both via CDN)
• Scraping — Playwright (Chromium)
• Store — Redis (cookie-based sessions + a 24 h cache of Spotify lookups)

Setup

cp .env.example .env
# then edit .env and fill in your keys

Key	Where to get it
SPOTIFY_CLIENT_ID / SPOTIFY_CLIENT_SECRET	Spotify developer dashboard → your app → Settings
SPOTIFY_REDIRECT_URI	http://127.0.0.1:8000/api/auth/callback
ANTHROPIC_API_KEY	console.anthropic.com (used for artist extraction)
REDIS_URL	redis://redis:6379 under Docker, redis://localhost:6379 otherwise
SESSION_SECRET	any random string

Register the redirect URI with Spotify

In the Spotify dashboard, add http://127.0.0.1:8000/api/auth/callback to your app's Redirect URIs and save. Use 127.0.0.1, not localhost — Spotify only allows plain http:// for loopback IP literals and rejects http://localhost. Then open the app at http://127.0.0.1:8000 (the session cookie is host-scoped).

Running

With Docker

docker compose up

Then visit http://127.0.0.1:8000.

Without Docker

pip install -r requirements.txt
playwright install chromium
redis-server &
uvicorn backend.main:app --reload

Tests

pip install -r requirements.txt
pytest tests/

Tests are fully mocked — no network calls or real browser.

Project layout

backend/
  main.py            FastAPI app, router wiring, static mount
  config.py          env-driven settings (pydantic-settings)
  scraper.py         Playwright page fetch + Claude artist extraction
  spotify.py         spotipy wrappers (search, top tracks, playlist create)
  scoring.py         taste profile + affinity scoring + track selection
  session.py         Redis-backed cookie sessions
  cache.py           sync Redis cache for Spotify lookups
  routers/           /api/scrape, /api/auth, /api/analyze, /api/playlist
frontend/
  index.html         single-page UI (Alpine.js)
  app.js             step state machine + fetch calls
  style.css          spinner + scrollbar
tests/
  test_scraper.py