Low-latency desktop and game streaming with first-class Linux and Windows hosts.

Run the host on a Linux machine or a Windows PC, connect from a Mac, PC, phone, tablet, or TV, and stream your desktop or games — each device at its own native resolution and refresh rate, over your local network.

📖 Documentation: docs.punktfunk.unom.io — start with How It Works or the Quick Start.

💬 Community: Discord — chat, support, and Android beta access · r/Punktfunk.

🔒 Security: found a vulnerability? Report it privately to security@punktfunk.com — see SECURITY.md. Please don't open a public issue.

punktfunk pairs a virtual-display streaming host with native clients on every platform. It speaks the existing GameStream protocol, so any Moonlight client works day one — and adds its own faster punktfunk/1 protocol that breaks the ~1 Gbps FEC wall with a GF(2¹⁶) Leopard-RS transport. A single shared Rust core (punktfunk-core) holds the protocol, FEC, and crypto, linked into the host and every native client — directly as a Rust crate on Linux and Windows, and over a stable C ABI from the Apple and Android apps.

What makes it different

• Your device's exact mode. For each client that connects, the host spins up a virtual display sized to that device — 1080p60 to a laptop, 1440p120 to a desktop, 4K to a TV, all at once. No letterboxing, no scaling, no rearranging your real monitors.
• Displays you configure, not just create. Keep a game's display (and the game) alive across disconnects so a reconnect drops straight back in; make the stream your sole desktop or extend alongside your monitors; let several devices become monitors of one desktop; keep each client's scaling. One-click presets in the console — a dedicated couch box, a shared desktop, a multi-monitor workstation. See Virtual displays.
• A real virtual display on Windows, too. On Linux the host uses per-compositor virtual outputs; on Windows you get the same on-the-fly virtual display — at the client's exact mode, no physical monitor or dummy HDMI plug, even on the secure desktop (UAC / lock screen). It also has its own indirect display driver (IDD) the host pushes finished frames straight into, rather than scraping a screen — tight, push-based integration that's unusual for a Windows streaming host.
• Low latency, GPU end to end. Frames go straight from the compositor to the NVENC encoder with zero CPU copies (dmabuf → CUDA/Vulkan → NVENC), over a transport tuned for responsiveness rather than throughput. Stable 240 fps at 5120×1440; sub-millisecond capture-to-reassembly on-box, ~1.3 ms cross-machine on a LAN. (AMD/Intel encode via VAAPI, and a GPU-less software H.264 encoder exists as a fallback.)
• Works with what you already have. Any Moonlight/Artemis client connects over GameStream — and native apps for macOS, Linux, Windows, and Android use the lower-latency punktfunk/1 protocol.
• Secure by default. Hosts require a one-time SPAKE2 PIN pairing; after that, devices reconnect on a pinned identity. No accounts, no cloud. Hosts auto-advertise over mDNS, so clients find them on the network without typing an IP.

Status

Component	State
Core — punktfunk-core + C ABI (protocol · FEC · crypto · QUIC)	✅ Complete & hardened
GameStream host → stock Moonlight	✅ Live end-to-end: pairing, RTSP, audio, per-client virtual output at native resolution, GPU zero-copy NVENC, gamepads
Native protocol — punktfunk/1	✅ Validated live: QUIC control + GF(2¹⁶) FEC/AES-GCM data plane, PIN pairing, mDNS discovery, mid-stream mode renegotiation
Windows host (Windows 11 22H2+, x64)	🟡 Implemented & shipping as a signed installer: its own all-Rust IddCx virtual display (secure-desktop capable) with a sealed IDD-push capture path — finished frames pushed straight into its own driver, not screen-scraped (no DDA/WGC) · GPU encode (NVENC on NVIDIA, AMF/QSV on AMD/Intel, software H.264 without a GPU) · WASAPI audio · bundled virtual-gamepad drivers (no ViGEmBus) · HDR incl. Vulkan-game HDR. NVIDIA live-validated; AMD/Intel CI-green
macOS / iOS / tvOS client (clients/apple)	✅ Streaming live: VideoToolbox decode (HEVC, and AV1 on hardware that decodes it), controllers incl. DualSense, discovery, pairing, speed test
Linux client (clients/linux + clients/session)	✅ Streaming live: relm4/GTK4 launcher shell that spawns a Vulkan session binary — Vulkan Video / VAAPI / software decode, PipeWire audio, SDL3 controllers, Skia console UI; ships as Flatpak/apt/rpm/Arch
Android client (clients/android, phone + TV)	✅ Streaming live: AMediaCodec decode + HDR10, AAudio audio, controllers, discovery, pairing
Windows client (clients/windows, WinUI 3)	✅ Streaming live: WinUI 3 shell + Vulkan session presenter, hardware decode on all GPU vendors via Vulkan Video → D3D11VA → software (NVIDIA + Intel validated on glass), WASAPI audio, SDL3 controllers, discovery, pairing; ships as signed MSIX (x64 + ARM64). HDR10 implemented, on-glass validation pending
Web console + management API (web/)	✅ TanStack console over the OpenAPI mgmt API: host status, paired devices, on-demand PIN pairing, GPU selection, performance capture graphs, live host logs

Every native client also ships a tiered stats overlay (Compact / Normal / Detailed) with a shared vocabulary across platforms, and the session client carries a full gamepad-driven console shell (pf-console-ui): host list, PIN pairing, settings, and an on-screen keyboard.

The GameStream host works with a stock Moonlight client — validated live on NVIDIA hardware (RTX 5070 Ti, RTX 4090): PIN pairing that persists across restarts, an app catalog, RTSP/ENet/audio, and video at the client's exact resolution and refresh via a per-session virtual output (KWin, gamescope, Mutter, and Sway/wlroots backends), encoded with GPU zero-copy (dmabuf → CUDA/Vulkan → NVENC) up to 5120×1440@240. The native punktfunk/1 protocol adds a QUIC control plane and a GF(2¹⁶) Leopard-FEC + AES-GCM data plane (p50 ~0.8 ms capture→received at 720p120), with mid-stream mode renegotiation and a wall-clock skew handshake so latency stays valid across machines. Both run from one process: bare punktfunk-host serve is the secure native-only default (punktfunk/1 + the management API/web console), and serve --gamestream additionally enables the GameStream/Moonlight-compat planes (opt-in, trusted-LAN only — GameStream has inherent on-path weaknesses). The host is managed through a REST API and web console. Builds against FFmpeg 7 or 8.

Full milestone status: docs.punktfunk.unom.io/docs/status · roadmap: /docs/roadmap.

Install the host

Pick your platform and install from its package registry — the per-platform guide covers adding the repo, first run, and the web console. The Linux host is the primary, most battle-tested path; a Windows host also ships as a signed installer (all-vendor: NVIDIA, AMD, Intel).

Platform	Install	Guide
Ubuntu / Debian (apt)	sudo apt install punktfunk-host (after adding the repo)	Ubuntu — GNOME · KDE
Bazzite / Fedora Atomic (systemd-sysext)	sudo bash punktfunk-sysext.sh install (no layering, no reboot; rpm-ostree + bootc also supported)	Bazzite
Fedora (dnf)	dnf install punktfunk punktfunk-web (after adding the repo)	Fedora — KDE
Arch / Steam Deck (pacman / sysext)	pacman -Sy punktfunk-host (binary repo) · sysext .raw (SteamOS)	packaging/arch
Windows (11 22H2+, x64)	signed setup.exe from the package registry	Windows Host

punktfunk-host is the streaming host; punktfunk-web is the browser console (pairing + status). After install, run punktfunk-host serve inside your desktop session (the secure native default; add --gamestream on a trusted LAN if you also want stock Moonlight clients), then pair from the web console. Full instructions: docs.punktfunk.unom.io/docs/install.

Connect a client

Streaming to…	Use
Mac, iPhone, iPad, Apple TV	The Apple app (clients/apple) — also on TestFlight
Linux desktop / laptop, Steam Deck	punktfunk-client (Flatpak / apt / rpm / Arch)
Android phone or TV	The Android app (clients/android)
Windows	Native punktfunk-client (signed MSIX) or Moonlight
Anything else (browser, old phone, smart TV)	Moonlight over GameStream

Each client discovers hosts on the network automatically and does a one-time PIN pairing. Per-device install steps: /docs/install-client.

Build & test (from source)

For development, or as an install fallback where no package is available:

cargo build --workspace          # core, host, tray, shared client crates, Linux shell + session client, probe (Linux & macOS)
cargo test  --workspace          # unit + loopback + proptest + C ABI harness
cargo clippy --workspace --all-targets -- -D warnings
cargo fmt --all --check

cargo run -p loss-harness        # FEC loss-resilience sweep (no network needed)
bash crates/punktfunk-core/tests/c/run.sh   # standalone C-ABI link + round-trip proof

The C header regenerates from crates/punktfunk-core/src/abi.rs on every build (cbindgen via build.rs) into include/punktfunk_core.h. The Apple, Android, and Windows clients have their own toolchains (Xcode/swift build, Gradle, and cargo on the MSVC target) — see each client's README and the docs site.

Layout

crates/
  punktfunk-core/   protocol · FEC · pacing · crypto · QUIC control plane — the C ABI (lib + cdylib + staticlib)
  punktfunk-host/   the host (Linux + Windows): virtual displays · capture · encode · input · GameStream · punktfunk/1 · mgmt
  pf-client-core/   shared client plumbing (Linux + Windows): session pump · FFmpeg decode · audio · SDL3 gamepads · trust · discovery
  pf-presenter/     Vulkan session presenter: SDL3 window · ash swapchain · frame present · input capture
  pf-console-ui/    Skia console UI for the session client: gamepad shell · stats OSD · pairing · on-screen keyboard
  pf-ffvk/          FFmpeg Vulkan hwcontext bindings (AVVkFrame) for Vulkan Video decode on the presenter's device
  pf-driver-proto/  host ↔ pf-vdisplay driver contract: control IOCTLs + IDD-push frame transport (no_std)
  punktfunk-tray/   host tray icon (Windows notification area / Linux StatusNotifierItem)
clients/
  apple/    macOS / iOS / tvOS app (Swift · VideoToolbox · Metal · GameController)
  linux/    Linux launcher shell (Rust · relm4 / GTK4 / libadwaita) — spawns the session client to stream
  session/  punktfunk-session, the Vulkan streaming session (Rust · SDL3 · ash · Skia console UI) — also runs standalone (gamescope, Decky)
  windows/  Windows desktop app (Rust · WinUI 3 · D3D11 · WASAPI · SDL3)
  android/  Android phone + TV app (Kotlin · Rust JNI core · AMediaCodec · AAudio)
  probe/    headless reference / measurement client for punktfunk/1
  decky/    Steam Deck Decky plugin
web/                         web console (TanStack) over the management API — status · devices · pairing · GPUs · performance · logs
api/openapi.json             management-API OpenAPI spec (regenerated via `punktfunk-host openapi`, checked in)
packaging/                   apt · rpm / COPR · Arch · Flatpak · Bazzite bootc image
docs-site/                   public documentation site (Fumadocs) — https://docs.punktfunk.unom.io
include/punktfunk_core.h     cbindgen-generated C header (checked in)
tools/                       latency-probe · loss-harness (measurement)
ci/                          CI container images (rust-ci · fedora-rpm)

Design invariants

• One core, linked everywhere. Protocol, FEC, and crypto live in punktfunk-core exactly once, exposed over a stable, versioned C ABI (punktfunk_abi_version(), PunktfunkConfig carries its own struct_size). Every native client links the same core.
• No async on the hot path. The per-frame pipeline uses native threads only; tokio/quinn are gated behind the off-by-default quic feature (control plane only).
• Native client resolution, no scaling. Each session gets a virtual output at exactly the client's WxH@Hz; each compositor keeps its own backend behind a shared VirtualDisplay trait.
• FEC is the wall-breaker. GF(2⁸) (≤255 shards/block) for Moonlight compatibility; GF(2¹⁶) (≤65535 shards/block, SIMD, O(n log n)) for punktfunk/1 to push past ~1 Gbps.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or https://opensource.org/licenses/MIT)

at your option — SPDX-License-Identifier: MIT OR Apache-2.0.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions. See CONTRIBUTING.md.

Third-party components

punktfunk's own source is MIT/Apache-2.0. Shipped binaries additionally link third-party components under their own (permissive) licenses — see THIRD-PARTY-NOTICES.txt (regenerate with scripts/gen-third-party-notices.sh). The Windows host and client builds also bundle FFmpeg under the LGPL v2.1+ (dynamically linked, replaceable DLLs; the license text and notice ship in the installed licenses/ folder).

Trademarks

punktfunk is an independent project and is not affiliated with, endorsed by, or sponsored by NVIDIA, Microsoft, Sony, Valve, or the Moonlight project. "GameStream", "Moonlight", "Xbox", "DualSense", "DualShock", and "PlayStation" are trademarks of their respective owners and are used here only to describe interoperability.