DeepSeek Harness

September 2, 2026 · View on GitHub

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DeepSeek Harness (dsh) is an open-source agent harness developed by DeepSeek AI.

It uses an architecture where everything is a plugin, and is powered by Cordis, whose design is described in A Programming Paradigm for Spatiotemporal Composability.

Unofficial desktop distribution

This community repository preserves the official source and adds an unofficial Intel macOS and Windows x64 desktop application under apps/desktop. It is not an official DeepSeek desktop release. The application embeds the existing Harness Web runtime in a native Electron window, owns a random loopback port, and ships the user-supplied whale icon.

Download the DMG or Setup executable from this repository's Releases. The current builds are unsigned; macOS may require Open from Finder's context menu on first launch, and Windows may show a SmartScreen prompt.

Desktop 0.5.2 builds the Intel macOS DMG and Windows x64 Setup from the same tested Harness 0.1.1-rc.2 source revision. It restores the v0.4.11 PromptRail, gives the existing Project/Session tree a clearer ChatGPT-like rhythm, keeps Review, Terminal, Browser, and Files in a fixed resizable Workbench, and adds a risk-confirmed Don't ask again this session action for the existing Full access preset. Startup phases are measured without skipping validation, while Windows packaging removes only unreachable platform assets and uses dedicated taskbar, tray, and installer icons. Exact legacy 0.4.x fallback migration, bounded local document attachments, and Memory & Learning remain intact. Windows remains installer-updated; the in-app updater is currently available only for Intel macOS.

Developer preview

DeepSeek Harness is currently in developer preview and is iterating rapidly. THERE WILL BE COMPATIBILITY-BREAKING CHANGES.

Run

Run from npm

Install Node.js, then run:

npx @deepseek-ai/dsh web

The command starts the Web UI at http://127.0.0.1:3080 by default and opens it in the default browser for a local launch. An SSH launch only prints the host URL because the SSH client or editor owns the local forwarded address. Pass --no-open to run the server without opening a browser. See Web UI guide.

Run from source

To run from a repository checkout:

git clone https://github.com/deepseek-ai/deepseek-harness.git
cd deepseek-harness
pnpm install
pnpm run build
pnpm dsh web

pnpm run build prepares the repository artifacts. pnpm dsh web uses those built artifacts without rebuilding.

Community and support

Contributing

See CONTRIBUTING.md.

Development

Start with the development guide and architecture documentation.

For agents, follow AGENTS.md.

License

MIT

Third-party dependencies and their licenses are disclosed in THIRD_PARTY_NOTICES.md.