DeepSeek Harness

DeepSeek Harness (dsh for short) is an open-source agent development framework officially released by DeepSeek. It is currently in developer preview and is licensed under the MIT License.

Its design philosophy can be summed up in one sentence: everything is a plugin. Models, tools, skills, sessions, sandboxes, storage, loops, scheduling, interfaces—all Agent capabilities exist as plugins. Developers install only what they need, and anything they don’t need never enters memory. The framework itself is built on a microkernel and provides only the most basic assembly capabilities.

The advantage of this structure is that you can swap models or toolchains without changing the core code; the downside is that when you first get started, you have to understand how the plugins are wired together, which makes the learning curve a bit steeper than with an out-of-the-box framework.

It’s suited to developers who want to build their own agent systems and don’t want to be locked into a particular model or toolset. The MIT license means it can be used commercially, which meaningfully lowers the barrier to adoption within enterprises.

The code is open source, and the documentation and plugin ecosystem are still in their early stages. We recommend evaluating stability before using it in production.