The short answer

DeepSeek Harness, or DSH, is DeepSeek’s open-source runtime for building and operating coding agents. It coordinates models, tools, sessions, workflows, sandboxes, the agent loop, and user interfaces. The Harness is the ecosystem core—not a Plugin.

The official package can start a local Web Profile. From there, you select a workspace, configure a model provider, run tasks, and inspect the Plugin surfaces attached to that Profile.

A clean Web Profile before a workspace is selected. This is the baseline to establish before adding a community Bundle.Harness 0.1.0-rc.7 · macOS 26.4 · Node.js 24.19 · isolated Web Profile · Captured 2026-08-20 · official source

The terms that determine your next action

  • Harness: the official runtime and ecosystem core.
  • Agent: the behavior that receives a task, chooses tools, and produces a result inside the runtime.
  • Model provider: the API-compatible service and model used by an Agent.
  • Profile: a named runtime configuration targeted by install, update, and remove actions.
  • Plugin Bundle: a distributable package whose manifest points to a DSH Bundle patch.
  • Skill: reusable instructions or knowledge that may ship inside a Bundle or independently.
  • Preset: a reusable starting configuration; it is not automatically a Plugin Bundle.
The Web Profile exposes separate settings surfaces for runtime preferences, models, and Plugins. Keeping those layers separate makes failures easier to isolate.Harness 0.1.0-rc.7 · macOS 26.4 · Node.js 24.19 · isolated Web Profile · Captured 2026-08-20 · official source

What a working baseline looks like

A useful baseline is deliberately small: the official CLI reports the expected version, the Web Profile loads, one safe workspace opens, one model is selectable, and a minimal task completes without a community Bundle.

Record the Harness version, Node.js version, target Profile, and model provider before extending the system. Those facts are more useful during recovery than a generic claim that the setup once worked.

A non-sensitive workspace is selected and ready. The next controlled step is model configuration, not bulk Plugin installation.Harness 0.1.0-rc.7 · macOS 26.4 · Node.js 24.19 · isolated Web Profile · Captured 2026-08-20 · official source

Why the Developer Preview label matters

Release candidates can change commands, configuration, and compatibility. DSHub therefore shows two separate facts: the rolling command recommended by the official README, and the pinned release candidate tested for this guide.

Treat screenshots as navigation evidence for the stated baseline, not a promise that every later release will look identical.

Start the official Harness →