# Rate Limits & Caching

## Throttling
- Requests are throttled per window (default 30s) to avoid bursts.
- Separate caps for sensitive endpoints.
- Configure via env:
```bash
SPOTIFY_RATE_WINDOW_SECONDS=30
SPOTIFY_RATE_MAX_REQUESTS=50
SPOTIFY_RATE_MAX_REQUESTS_SENSITIVE=20
```

## 429 handling
- If Spotify returns 429, respects `Retry-After` and retries (up to 3 attempts).

## Response caching
- GET responses cached: search ~10 minutes, album ~1 hour.
- Token responses are cached separately.

## Batching
- `getAlbums([ids])` provided for batch lookups.