What is DeepSeek Harness
The core idea, architecture and three entry modes of DeepSeek Harness
DeepSeek Harness (the dsh command) is an open-source agent harness developed by DeepSeek AI. Its core idea fits in one sentence:
Everything is a Plugin
Every capability of the harness — tools, skills, goals, subagents, UI blocks, model routing — exists as a plugin and is composed together by Cordis. The design is described in the paper A Programming Paradigm for Spatiotemporal Composability.
What it can do
Within a session, the agent can:
- Read and edit files: read, create and modify files in the workspace;
- Run commands: execute shell commands under your approval;
- Delegate work: dispatch subagents to handle independent tasks in parallel;
- Orchestrate workflows: break complex tasks into multi-phase pipelines;
- Use skills: load specialized skills such as docs writing and code review;
- Pursue goals: keep pushing a long-running objective across many rounds;
- Extend itself: add new capabilities at runtime via dynamic plugins.
Three entry modes
| Mode | Command | Best for |
|---|---|---|
| Web GUI | dsh web (or npx @deepseek-ai/dsh web) | Daily use: chat, approvals, workspace management |
| Headless | dsh --profile headless "task" | Scripted one-shot tasks, CI integration |
| Plugin management | dsh plugin --profile <name> ... | Install/remove plugins for a profile |
The web and headless profiles auto-initialize on first use from shipped templates; other profiles are created via dsh plugin.
The big picture
Key concepts at a glance
- Profile: an ordered stack of plugin-bundle patch layers deciding which capabilities an entry loads.
- Agent Preset: the per-session agent composition (persona, prompts, tools, skills) from
cordis.ymlfiles. - Skill: reusable task-oriented instruction packs loaded on demand (e.g.
astro,code-review). - Goal: a durable completion objective that advances across rounds.
- Subagent / Workflow: subagent delegation and multi-agent orchestration.
- Dynamic Cordis plugins: temporary runtime extensions adding Host capabilities and browser Client UI.
Who is it for
- Vibe Coding / AI office newcomers: install and go — describe your goal in natural language; the agent handles files and commands.
- Experienced users: shape the harness with profiles, presets, skills and workflows.
- Plugin developers: extend everything with the Cordis composition model, see the developer guide.
Heads-up
Developer preview
The harness is in the developer preview stage and iterating rapidly. Breaking changes are expected. Assess risks before production use.
Next: Installation