punktfunk/docs-site/content/docs/status.md

title, description

title	description
Status & Progress	Where the work stands across the core, the host, and the native clients.

A high-level view of where punktfunk stands. The ordered plan of work is on the Roadmap, and milestone-level detail lives in CLAUDE.md.

Milestones at a glance

Milestone	State
Core — punktfunk-core + C ABI (protocol · FEC · crypto)	✅ complete & hardened
GameStream host (Moonlight-compatible)	✅ working end-to-end; HDR/surround-audio polish open
Native protocol — punktfunk/1 (QUIC control + UDP data, GF(2¹⁶) Leopard FEC + AES-GCM)	✅ full session planes, validated live
Windows host (NVIDIA, x64)	🟡 implemented & shipping as a signed installer; NVIDIA-only, newer than the Linux host
macOS / iOS / iPadOS / tvOS client	✅ full client; on-glass stage-2 presenter behind an opt-in flag, becoming the default
Linux client (punktfunk-client, GTK4/libadwaita)	✅ full client; VAAPI zero-copy decode + software fallback
Windows client (punktfunk-client, WinUI 3)	✅ stage 1 complete; ships as signed MSIX; on-glass hardware validation pending
Android client (phone + Android TV)	✅ full client; hardware HEVC decode + HDR10
Web console (over the management API)	✅ status · devices · pairing

What works today

punktfunk is a low-latency desktop and game streaming host with first-class Linux and Windows support — and native clients on macOS, iOS/iPadOS/tvOS, Linux, Windows, and Android. (The Windows host is newer than the Linux host.)

• Two protocols. The host speaks the GameStream protocol, so any Moonlight client works out of the box, plus its own lower-latency punktfunk/1 protocol (QUIC control plane + UDP data plane with GF(2¹⁶) Leopard FEC and AES-GCM).
• Native resolution, no scaling. Every session gets a virtual display at the client's exact resolution and refresh rate, via per-compositor backends for KWin, gamescope, Mutter, and Sway/wlroots.
• Zero-copy GPU pipeline. Captured frames stay on the GPU (dmabuf → CUDA → NVENC) with automatic split-encode at very high resolutions. Stable 240 fps at 5120×1440 has been measured.
• HDR (10-bit), on the Windows host. An HDR Windows desktop is captured and encoded as HEVC Main10 (BT.2020 PQ) to HDR-capable clients (Windows, Android). Linux hosts stream 8-bit for now — HDR there is blocked upstream at the compositor.
• Secure by default. A SPAKE2 PIN pairing ceremony establishes trust (the host shows a 4-digit PIN; an attacker gets a single online guess, no offline dictionary attack). Trust-on-first-use (TOFU) remains an explicit opt-in for fully trusted LANs.
• LAN auto-discovery. Hosts advertise over mDNS (_punktfunk._udp); clients browse and list them automatically.
• Full input. Mouse, keyboard, and gamepads (including DualSense touchpad, motion, rumble, lightbar, player LEDs, and adaptive triggers) in both directions.
• Audio both ways. Opus desktop audio host → client, plus an opt-in, paired-only client microphone uplink.
• Management surface. A REST management API with a checked-in OpenAPI document, plus a web console for status, paired devices, and pairing.

Native clients

Client	Highlights
macOS / iOS / iPadOS / tvOS	VideoToolbox HEVC decode, GameController capture, full DualSense feedback, mDNS discovery, PIN pairing + TOFU, network speed test, latency HUD. Stage-2 presenter (VTDecompressionSession → CAMetalLayer, ~11 ms p50 capture→present) is built and validated on glass behind an opt-in flag, becoming the default. Ships as one universal TestFlight build / App Store listing.
Linux (punktfunk-client)	GTK4/libadwaita. FFmpeg decode with VAAPI → DRM-PRIME dmabuf zero-copy (Intel/AMD; software fallback on NVIDIA), PipeWire audio + mic, SDL3 gamepads incl. DualSense, mDNS discovery, PIN pairing + TOFU, speed test. Ships as Flatpak, apt, rpm, and Arch packages.
Windows (punktfunk-client)	WinUI 3. D3D11VA zero-copy decode, HDR10, WASAPI audio + mic, SDL3 gamepads incl. DualSense, mDNS discovery, and the full PIN/TOFU trust surface are all implemented. Ships as a signed MSIX (x86_64 + ARM64). Stage 1 complete; D3D11VA decode, HDR present, and the GUI are pending on-glass validation on real GPU hardware.
Android (phone + Android TV)	Kotlin app with a Rust core over JNI. NDK AMediaCodec hardware HEVC decode + HDR10 (Main10/BT.2020 PQ), Opus/Oboe audio + mic, gamepad input with rumble/HID feedback, mDNS discovery, PIN pairing + TOFU (Keystore identity), live stats HUD, and D-pad/controller focus navigation for TV. Ships to the Google Play Internal Testing track.

punktfunk-probe is a headless reference and measurement client (for testing and benchmarking, not everyday use).

Validated live on

The stack has been validated live on a range of hosts and clients:

• Hosts: Ubuntu (GNOME / KDE), Fedora KDE, and Bazzite (gamescope) on machines with RTX-class NVIDIA GPUs, across the KWin, gamescope, Mutter, and Sway/wlroots backends.
• Clients: native macOS, Linux, and Android clients against live hosts, plus stock Moonlight clients over the GameStream path.
• Cross-machine latency is measured and skew-corrected (a wall-clock handshake removes the inter-machine clock offset), so capture-to-present numbers are valid across the LAN.

Highlights

Notable capabilities that have landed, newest first:

• Native Linux client (stage 1). GTK4/libadwaita app that links punktfunk-core directly: mDNS host list, TOFU + SPAKE2 PIN pairing, FFmpeg HEVC decode, PipeWire audio with mic uplink, SDL3 gamepad capture with rumble/lightbar feedback, layout-independent keyboard, absolute mouse, fullscreen, and a stats overlay. VAAPI → GdkDmabufTexture zero-copy decode on Intel/AMD with a proven software fallback.
• Delegated pairing approval. An unpaired device that knocks on a pairing-required host appears as a pending request in the web console's Pairing page; one click approves and pins its certificate — no PIN fetched out of band.
• Concurrent sessions. The host serves multiple clients at once (bounded by an NVENC limit), each with its own virtual output and encoder — e.g. stream the same desktop to a laptop and a TV simultaneously.
• Cross-machine latency HUD + wall-clock skew handshake. A short NTP-style handshake aligns client and host clocks, making capture-to-reassembled latency valid across machines; the Apple client surfaces a skew-corrected capture-to-receipt p50/p95 in its HUD.
• Native LAN auto-discovery. Hosts advertise _punktfunk._udp over mDNS (with TXT records carrying the protocol, cert fingerprint, and pairing requirement); clients discover and list them automatically.
• 1 Gbps data plane. Batched sendmmsg/recvmmsg, a microburst-capped paced send thread, and larger socket buffers, exploiting the GF(2¹⁶) Leopard FEC that breaks the classic ~1 Gbps GameStream ceiling.
• Boot appliance. A headless compositor session plus host systemd units, so a host can come up and stream with no interactive login.
• Network speed test + settable bitrate. Bitrate negotiation and an in-band bandwidth probe inform the client's bitrate picker instead of guesswork.
• Rich DualSense. A full UHID DualSense backend on the host (gamepad, motion, touchpad, lightbar, player LEDs, adaptive triggers) with feedback carried back to the clients.
• AV1 + surround audio are implemented and unit/live-capture tested.

In flight / next

See the Roadmap for the ordered list. Near-term:

• True glass-to-glass latency — combine the client present-stamp (decode → present) with the host render → capture term for a complete end-to-end number.
• Make the Apple stage-2 presenter the default after a few more resolution/HDR checks.
• On-glass validation of the Windows client (D3D11VA decode, HDR present, GUI) on real GPU hardware.
• gamescope multi-user isolation — per-session input/audio so concurrent sessions can be fully independent desktops (the shared-desktop multi-view case already works).