# spotify-last-known

Tiny background service that:

1. Polls Spotify `currently-playing`
2. Persists the last known track to a local JSON file
3. Serves it publicly over HTTP (with CORS)

## Setup

Create an `.env` (or export env vars) with:

- `SPOTIFY_CLIENT_ID`
- `SPOTIFY_CLIENT_SECRET`
- `SPOTIFY_REFRESH_TOKEN`

Optional:

- `PORT` (default: `9783`)
- `POLL_MS` (default: `8000`)
- `STATE_PATH` (default: `./data/last-known.json`)

## Run

```bash
npm i
npm start
```

Endpoints:

- `GET /last-known` -> persisted state JSON, including `isPlaying`, `progressMs`, and `startedAtMs` while active so static clients can animate playback progress
- `GET /healthz` -> `{ ok: true }`

## Notes

- Intended for a single machine / single instance.
- JSON is written atomically using a temp file + rename.