Introduction

Shen is the desktop client for Aethersea. It connects to a Leviathan server over WebRTC and renders the remote desktop or game stream with low end-to-end latency.

This documentation covers the desktop client (Windows, macOS, Linux). The iOS and Android clients are separate projects with their own builds and differ in feature coverage.

Supported Platforms

Key Features

• Hardware-accelerated decoding — D3D11VA / NVDEC on Windows, VideoToolbox on macOS, VAAPI on Linux. HEVC is hardware-only (no software fallback); AV1 falls back to rav1d (pure-Rust) where hardware AV1 decode is unavailable.
• Multi-session — connect to several Leviathan servers at once, each in its own window.
• Full input — keyboard, mouse (relative and absolute), high-precision scroll, and up to 16 gamepads via SDL3 with rumble and motion sensor support where available.
• Immersive mode — global keyboard and mouse hooks so system shortcuts (Alt+Tab, Cmd+Tab, Win/Cmd key, etc.) are forwarded to the host instead of being eaten by the client OS.
• Remote desktop mode — absolute mouse with a visible local cursor, for productivity use.
• Clipboard sync — bidirectional text, images, and files. On macOS this is handled by a bundled clipboard-helper process.
• Performance overlay — live RTT, packet loss, FEC recovery rate, codec, resolution, and frame rate, driven by a dedicated telemetry DataChannel from the server.
• Encrypted transport — DTLS-SRTP for media, DTLS/SCTP for DataChannels, TLS for signaling. Pairing credentials live in the OS keyring.

Architecture

Shen is an Electron app with a Rust native addon loaded in the preload script:

• Electron + React 19 + MUI 7 for the UI and Chromium-side WebRTC media transport.
• Rust (napi-rs) compiled to a .node shared library for gRPC signaling, input injection, gamepad (SDL3), global hooks, AV1 software decode, and WebRTC control/telemetry/clipboard DataChannels.
• Protocol Buffers for everything on the wire between Shen and Leviathan.

Video frames cross process boundaries through SharedArrayBuffer ring buffers — the native addon is loaded in the preload (not the main process) so the renderer can read frames directly with no IPC serialization.

Next Steps

• Getting Started — install Shen and pair with a Leviathan server.
• Features — details on each of the capabilities above.
• Keyboard Shortcuts — client-side hotkeys.
• Configuration — per-server stream settings and where they're stored.