Architecture overview

Understand how the Tauri shell, local Harness service, and embedded web UI work together.

DeepSeek Harness Desktop is a Tauri 2 application that manages a local Harness service and displays its web interface inside a native window.

Main layers

Layer	Technology	Responsibility
Desktop UI	React 19, TypeScript, Vite, Tailwind CSS 4	Setup, settings, profiles, plugins, updates, and native window states
Native backend	Rust and Tauri 2	Runtime discovery, downloads, service lifecycle, files, CLI integration, and OS APIs
Harness service	Managed or compatible local dsh core	Sessions, tools, profiles, plugins, and the local web application
Embedded client	Harness web UI at a loopback URL	The primary session experience inside the desktop window

Startup flow

1. Resolve configuration

   Rust derives release or debug paths, the active profile, preferred core, and port.

2. Prepare dependencies

   The workflow reuses compatible system tools where appropriate and otherwise prepares the managed Node.js, pnpm, and prebuilt Harness core.

3. Ensure plugins

   Required internal plugins are checked and restored before the service starts.

4. Launch and probe Harness

   The backend starts a loopback-only process conceptually equivalent to dsh --profile <profile> --host 127.0.0.1 --port 3080, then waits for health.

5. Load the client

   The native window switches from setup or loading state to the local Harness UI.

Trust boundaries

The web client, Rust backend, Harness process, plugins, model providers, and opened workspace are separate components but not separate security sandboxes. Tauri commands narrow native capabilities; Harness tools and plugins can still execute local code with the user’s permissions.

Next, inspect Runtime and data or the Plugin system.