DSH | Nailong Harness | Lightweight native Windows launcher and lifecycle controller

[AAAAd-arch]

Unofficial community project. Nailong Harness is independently developed and maintained and is not affiliated with or endorsed by DeepSeek.

Nailong Harness

Nailong Harness is a lightweight native Windows launcher and lifecycle controller for the official DeepSeek Harness.

It does not replace or reimplement the Harness Web UI. Nailong is a Windows companion launcher rather than an in-process DSH plugin: it keeps the official @deepseek-ai/dsh package upstream and focuses only on the Windows-side experience around it.

Project:
https://github.com/AAAAd-arch/nailong-harness

Current release:
https://github.com/AAAAd-arch/nailong-harness/releases/tag/v0.3.0-rc3

Demo

Why I built it

DeepSeek Harness already provides the Web UI, so I did not want to build another frontend or maintain a fork of the upstream interface.

What I wanted was a small native Windows layer that makes Harness easier to start and manage:

double-click → start Harness → wait until ready → open the official Web UI → manage it from the system tray

The goal is to keep Nailong thin and let DeepSeek Harness remain authoritative.

What Nailong adds on Windows

• Native WinForms startup UI and system-tray controls.
• Starts the official @deepseek-ai/dsh package and waits until Harness is actually ready before opening the browser.
• Distinguishes between Managed Harness instances started by Nailong and External instances started elsewhere.
• Reuses an existing External Harness without taking ownership of it.
• Never terminates an External Harness process that Nailong did not start.
• Verifies that the local endpoint is really Harness instead of assuming that any process listening on the port is valid.
• Prefers a compatible system Node.js installation when one is already available.
• When necessary, can prepare an application-private Managed Node.js runtime without permanently modifying the user's PATH.
• Handles retry, cancellation, single-instance behavior, and cleanup of processes owned by Nailong.
• Can check for newer upstream DeepSeek Harness releases.

How it integrates with DSH

Nailong deliberately avoids patching, embedding, or replacing DeepSeek Harness.

When starting a Managed instance, Nailong launches the official DSH package, monitors its startup, verifies the local Harness endpoint, and opens the official Web UI in the user's default browser once it is ready.

If a compatible Harness instance is already running, Nailong can recognize and reuse it as an External instance. In that case Nailong provides access to it, but does not claim ownership and will not terminate it.

This separation between Managed and External instances is intentional: the launcher should only control processes that it owns.

Runtime behavior

Nailong follows a system-first approach for Node.js:

compatible system Node.js → use it

no compatible Node.js → offer a private Managed Runtime

The Managed Runtime belongs only to Nailong. It does not install Node.js system-wide or permanently modify the user's environment variables.

DeepSeek Harness itself remains the official upstream package.

Current release

v0.3.0-rc3 — Windows x64 pre-release

The current package is framework-dependent and requires:

• Windows x64
• .NET 10 Desktop Runtime (x64)

Node.js does not need to be installed manually if Nailong uses its private Managed Runtime fallback.

This is still a pre-release, so feedback and testing are very welcome — especially around Windows startup behavior, different Node.js environments, lifecycle handling, and general usability.