Rust becomes the single owner of which stream to play — direct play or
transcode, at what ceiling, over what transport — and hands every player
backend a self-describing StreamSelection instead of a bare URL. mpv,
ExoPlayer and the HTML5/hls.js path all consume one decision rather than
three places re-deriving it.
The motivating leak is concrete. VideoPlayer.svelte determines transport with
`currentStreamUrl.includes(".m3u8")`, in two places, for a URL Rust
constructed and therefore already knows the shape of. That is the boundary
rule in miniature: not item-type taxonomy, but the same error of
reconstructing a domain fact in the presentation layer because the wire shape
did not carry it. A tagged Transport enum deletes it.
The design line, which ExoPlayer forces: Rust decides *what stream*, the
player decides *how to deliver it*. ExoPlayer has genuine adaptive track
selection; this spec must not reimplement or fight it. Rust only adapts where
the player cannot (mpv) and the server actually offers a ladder.
Six phases, and phase 1 stands alone as pure ownership movement with no
behaviour change. Phase 4 (direct-play negotiation) is what removes the
transcode and unblocks the Linux native-video work. Phase 5 (adaptation) is
gated on counting EXT-X-STREAM-INF entries in a real playlist — the
acceptance criteria require that count be recorded before it is either
started or dropped.
Takes DR-121 from read-through-media-cache.md, which specced Rust-owned
quality reporting but never built it; that spec keeps its capture half.

JellyTau
A cross-platform Jellyfin client built with Tauri, SvelteKit, and TypeScript.
Business logic lives in a Rust backend; a UI-rich Svelte frontend handles presentation and talks to it over Tauri's IPC. Targets Linux (libmpv) and Android (ExoPlayer).
Getting Started
This project uses bun as its package manager.
# Activate the Rust environment (fish shell)
source "$HOME/.cargo/env.fish"
# Install dependencies
bun install
# Run in development
bun run tauri dev
# Type-check the frontend
bun run check
# Build for Linux
bun run tauri build
# Build for Android
bun run tauri android build
For the full set of build, test, and Android helper scripts, see scripts/README.md.
Documentation
| Topic | Location |
|---|---|
| Architecture overview & subsystem docs | docs/architecture/ |
| Requirements, traceability & technical debt | docs/requirements.md |
| Build & release process | docs/build/build-release.md |
| Docker builds | docs/build/docker.md |
| Traceability tooling & CI | docs/traceability.md, docs/traceability-ci.md |
| Release checklist | docs/release-checklist.md |
| UX flows | docs/ux-flows.md |
| CI operations (builder image, secrets, runner) | docs/build/ci-operations.md |
Contributing
CONTRIBUTING.md covers the setup, the gates a change has to pass, and the two rules that catch people out (bug fixes start with a failing test; Jellyfin's taxonomy stays in Rust). Please also read the Code of Conduct.
Found a security problem? Do not open an issue — see SECURITY.md.
Verifying a download
Every release publishes SHA256SUMS covering all of its artifacts, plus an SBOM
of what went into the build:
sha256sum -c SHA256SUMS
Desktop builds update themselves from Settings → Updates, verifying each payload against JellyTau's signing key before installing. Android installs are handled by the system installer, so the app links to the releases page instead.
Recommended IDE Setup
VS Code + Svelte + Tauri + rust-analyzer.
License
MIT