# ADR-0001: Library as single source of truth for media

## Status

Accepted

## Context

The system originally had two representations of media: MediaItem (fetched live from providers at schedule-generation time) and LibraryItem (cached in the local database for browsing). The schedule engine bypassed the library entirely and queried providers directly, creating a tight coupling to provider availability and duplicating the concept of "a piece of media."

## Decision

The local library is the single source of truth for all media in the system. Providers (Jellyfin, Plex, local files, YouTube, etc.) are sync sources only — they feed items into the library, but are never queried at runtime by the schedule engine.

One unified type — MediaItem — lives in the library. The schedule engine queries the library, not providers.

## Consequences

- Schedule generation works even when a provider is offline.
- No more two-type split (MediaItem vs LibraryItem) — one concept, one type.
- Provider adapters become sync-only: their job is to discover items and upsert them into the library.
- Stream URL resolution still needs the provider at playback time (the library stores metadata, not video files). This is the one runtime provider dependency.
- Filters (genres, decade, content type, etc.) operate on library data, not provider APIs.