Architecture

Applies to the nori repository at 0.6.

nori is one Rust core with thin clients around it. Every decision lives once, in Rust, and is tested there; the clients (Kotlin, Slint, ratatui, Swift) draw, hold the words, and wire the operating system.

┌──────────── clients: drawing, words, OS hooks ────────────┐
│ Android (app/, core/)  desktop  terminal  iPod (ios/)     │
├──────────── nori-host: the session every client shares ───┤
│ nori-engine: the player on its own thread, in bursts      │
├──────────── nori-core: Core per server, the Client ───────┤
│ player · library · queue · lyrics · settings · devices    │
│ covers · look · automix · transfers · db · net · model    │
└───────────────────────────────────────────────────────────┘

The layers

• The domain crates each own one area: decoding and the sound chain (player), the library and its pages (library), the queue and autofill (queue), lyrics (lyrics), settings (settings), outputs and AutoEQ (devices), covers (covers), colors from covers (look), and so on.
• nori-core holds a Core per server profile and the Subsonic Client, and re-exports every domain crate, so a client can link it alone.
• nori-engine is the whole player for a platform without one: it loads in bursts, decodes, runs the sound chain and transitions, and sleeps in between. Android, the desktop, the terminal and the iPod all play through it.
• nori-host is the session the desktop, terminal and iPod share: engine, queue saving, remote control and jams, search, covers.

The table of every crate, with what it holds, is in AGENTS.md.

The rules that shape it

• The core returns data and enums, never text a person reads. Every word is the client’s.
• Calls across the boundary are coarse: one page or one answer per call. Anything per frame or per buffer goes through a thin native door with no allocation.
• Every optional feature sits behind a setting, and costs nothing when it is off.
• Where a piece of work lives is decided by measurement. See Writing a client.

Docs versions

The docs are published from docs/site/ as they are on master, as “latest”. Versioned docs can be added later by building the site from each release tag into its own path.