m3-host is now a real host, not a one-shot demo. Everything validated live on this box (two back-to-back sessions, pinned + TOFU, ~200 audio pkts/s, p50 0.84 ms at 720p60). lumen-core: - quic.rs: QUIC-datagram side planes demuxed by first byte — Opus audio 0xC9 ([magic][u32 seq][u64 pts_ns][opus], host→client) and rumble 0xCA ([magic][pad][low][high]). - Trust: endpoint::server_with_identity (persistent PEM identity) and endpoint::client_pinned — SHA-256 cert-fingerprint pinning with TOFU (observed fingerprint reported back for persisting). The verifier checks the TLS 1.3 CertificateVerify signature for real (an MITM replaying the host's public cert without its key is rejected; cert pinning alone would not prove key possession). - client.rs: NativeClient gains pin + host_fingerprint, audio/rumble receivers (next_audio / next_rumble); pull methods take &self so the C ABI's per-plane threads never alias a &mut (per-plane mutexed borrow slots in abi.rs). - abi.rs: lumen_connect(pin_sha256, observed_sha256_out) + lumen_connection_next_audio / next_rumble. input.rs: documented gamepad wire contract (GameStream buttonFlags bits, XInput axis conventions, +y = up) — exported as LUMEN_BTN_*/LUMEN_AXIS_* (bare BTN_* collides with <linux/input-event-codes.h> at different values). lumen-host (m3): - Persistent accept loop: sessions back to back on one endpoint (--max-sessions, 0 = forever); per-session failures log and the loop keeps serving; 10 s handshake deadline so a silent client can't wedge the sequential accept queue; teardown on every exit path (stop flag → conn.close → join audio+input threads). - Audio plane: desktop PipeWire capture → Opus 48 kHz stereo 5 ms CBR → datagrams; ONE capturer reused across sessions via an AudioCapSlot (PipeWire streams have no cheap teardown — per-session opens would leak a thread + core connection + live node each). - Gamepad routing: incremental GamepadButton/GamepadAxis datagrams accumulate into per-pad state feeding the uinput xpad manager; force feedback returns as rumble datagrams, with current state re-sent every 500 ms (idempotent-state healing for the lossy channel). QUIC endpoint serves the persistent ~/.config/lumen identity and logs the pinnable fingerprint. lumen-client-rs: --pin (malformed values abort — never silently downgrade to TOFU), TOFU fingerprint logging, audio/rumble datagram counters, gamepad events in --input-test. clients/apple: scaffold synced — pinSHA256/hostFingerprint (wrong-size pin throws, fail-closed), nextAudio/nextRumble, gamepad event constructors; README handoff updated (persistent listener, audio decode notes, trust UX). Adversarially reviewed (5-dimension multi-agent pass over the diff, 2-skeptic verification): fixed the MITM signature-check gap, a Y-axis contract inversion, header macro collisions, ABI aliasing UB, the PipeWire per-session leak, the missing handshake deadline, fail-open pin parsing, and teardown-on-error paths. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
lumen
A ground-up low-latency desktop streaming stack, built Linux-first, with a shared Rust protocol core and native clients per platform.
lumen is a placeholder codename. The bet: ship a Linux virtual-display streaming
host that speaks the existing Moonlight protocol (every Moonlight/Artemis client works
day one), then break the ~1 Gbps FEC wall with a GF(2¹⁶) Leopard-RS transport as a
negotiated extension. See docs/implementation-plan.md.
Status
| Milestone | State |
|---|---|
M1 — lumen-core + C ABI |
✅ done & tested (FEC, packetization, crypto, session, lumen_core.h) |
M0 — pipeline spike (wlroots→PipeWire→NVENC→file→lumen-core) |
✅ done & verified on NVIDIA (RTX 5070 Ti / driver 595) |
| M2 — P1 host → stock Moonlight | 🟡 capture+encode landed in M0; pairing/RTSP/vdisplay pending |
| M3 — measurement harness | 🟡 tools/loss-harness runs; latency-probe scaffolded |
| M4 — P2 transport + Rust client | 🟡 GF(2¹⁶) core done; lumen-client-rs scaffolded |
| M5 — Apple client | ⬜ scaffolded (clients/apple) |
lumen-core is complete and verified: it builds and its full test suite (FEC recovery,
loopback round-trip under loss, property tests, and a C ABI harness) passes on
macOS/aarch64. M0 is done: lumen-host captures a headless wlroots output via the
ScreenCast portal + PipeWire, encodes it with NVENC, writes a playable H.265 file, and
round-trips every access unit through a lumen_core host→client session (see
docs/linux-setup.md). M2 is in flight: the GameStream control plane (gamestream/) and
the management REST API (mgmt.rs, OpenAPI spec in docs/api/) are implemented; the
remaining Linux host backends (KWin/Mutter virtual displays, libei input) are
#[cfg(target_os = "linux")] seams — defined and compiling, implementations pending.
Layout
crates/
lumen-core/ protocol · FEC · pacing · crypto — the C ABI (lib + cdylib + staticlib)
lumen-host/ Linux host: vdisplay · capture · encode · inject · gamestream · mgmt
lumen-client-rs/ reference client (M4): VAAPI decode + wgpu present
clients/{apple,android}/ native client scaffolds (import lumen_core.h)
include/lumen_core.h cbindgen-generated C header (checked in)
tools/{latency-probe,loss-harness}/ measurement (plan §10)
docs/implementation-plan.md
Build & test
cargo build --workspace # green on Linux and macOS
cargo test --workspace # unit + loopback + proptest + C ABI harness
cargo clippy --workspace --all-targets
cargo run -p loss-harness # FEC loss-resilience sweep (no network needed)
bash crates/lumen-core/tests/c/run.sh # standalone C-ABI link+round-trip proof
The C header regenerates from crates/lumen-core/src/abi.rs on every build (cbindgen via
build.rs) into include/lumen_core.h.
Design invariants
- One core, linked everywhere. Protocol/FEC/crypto/pacing live in
lumen-coreexactly once, exposed over a stable, versioned C ABI (lumen_abi_version(),LumenConfigcarries its ownstruct_size). - No async on the hot path. The per-frame pipeline uses native threads only;
tokio/quinnare gated behind the off-by-defaultquicfeature (control plane only). - FEC is the wall-breaker. GF(2⁸) (≤255 shards/block) for Moonlight compat; GF(2¹⁶) (≤65535 shards/block, SIMD, O(n log n)) to push past ~1 Gbps.
License
MIT OR Apache-2.0.