kurl

Cross-platform music link resolver built with Flutter and Python on Cloudflare Workers. Paste a Spotify/Apple Music/Tidal/etc. link and get back the same track on Spotify, Apple Music, YouTube Music, SoundCloud, Beatport, Bandcamp, Amazon Music, Tidal or Deezer, resolved via ISRC/UPC matching with an Odesli fallback.

kurl.online

Components

• api: Cloudflare Workers Python service. Parses the source URL, resolves via ISRC/UPC against the source and target platform APIs (via=isrc/upc), falls back to a rescue-resolver chain (iTunes, Genius, Last.fm, DuckDuckGo search) for platforms without a native client, then Odesli, then a search-page deep-link (via=search). Results cached in KV; every kurl and page view logged to D1 for the /admin analytics console.
• app: Flutter client (iOS, Android, Web). Share-sheet and universal-link intake, platform picker, result card. Calls POST /api/kurl.

All communication between app and api runs over the public HTTP API - see .assets/API.md.

Resolution Order

Fast path first, cheapest and most confident match wins:

1. KV cache hit
2. Direct ISRC/UPC lookup against source + target platform APIs
3. Rescue-resolver chain (target-specific)
4. Odesli fallback (by-id or by-url)
5. Search-page deep-link into the target platform

Full breakdown: .assets/ISRC_KURLER.md.

Running the Project

Stack

• Python on Cloudflare Workers (Pyodide runtime), Cloudflare KV + D1
• Flutter (iOS, Android, Web)
• GitHub Actions (lint, deploy, smoke test)

1. Run the API

cd api
pip install uv
uv tool install workers-py
pywrangler dev

Serves on http://localhost:8787, live reload on file change.

2. Run the app

cd app
flutter pub get
flutter run

Debug builds probe localhost:8787 and fall back to prod if the worker is offline.

License

MIT