Released
13 Aug 2026
First public preview. npm next is 0.1.2-rc.1, published 3 September 2026.
DeepSeek Harness
DeepSeek Harness is a plugin-first local agent runtime. Released as a developer preview, it provides plugins for models, tools, skills, sessions, sandboxes, storage, loops, scheduling, and a web interface.
npx @deepseek-ai/dsh web
MIT on 0.1.x. Developer preview. Node.js ^22.19.0 or >=24. Web UI on 127.0.0.1:3080.
License
MIT
0.1.x packages. Inspect, modify, and self-host under the MIT License.
Status
Developer Preview
Compatibility-breaking changes. Not security-audited. Pin the version you run.
Runtime plugin directory
Extend the harness with one focused capability
The official Settings list shows 159 installed rows. Filter by family, search by name, and open any row on the Features page.
9 plugins
Models
llm
Model plugins, including llm. Swap the model without editing DeepSeek Harness source.
Settings → Plugins
Tools
tools
File editing, shell, file and web search. Standard mode ships the full tool surface.
Standard mode
Skills
skills
Skill plugins the agent can load. Missing tools are often load order or a denied Service.
Cordis plugins
Sessions
session
Session plugin and the append-only log. Trajectory resume, fork, search, and replay read the same stream.
Trajectory
Sandboxes
sandboxes
File-effect sandbox. Windows uses an ACL restricted-token backend. Do not treat prompts as containment.
windows-acl
Storage
storage
Storage plugins. Optional SQLite session backend was removed in 0.1.2; export from an older build if you still need it.
0.1.2-rc.1
Loops
loops
Agent loops keep the model working outside a chat box. Code / PTC can combine multi-step tool work in one TypeScript program.
Code / PTC
Scheduling
scheduling
Subagent scheduling is written into the session log. Resume and replay use those records.
Session log
Interface
api-gateway
Local Web UI on 127.0.0.1:3080, including api-gateway. Do not expose the port.
127.0.0.1:3080
What DeepSeek Harness means right now
A plugin-first local runtime around models. Developer preview. MIT on 0.1.x. The Web UI binds to 127.0.0.1:3080.
Release channel
Developer Preview
0.1.2-rc.1 on npm next, published 3 September 2026. Compatibility-breaking changes. Pin the version you run.
Install path
npx or source
Node.js ^22.19.0 or >=24. npx @deepseek-ai/dsh web or clone the published tree. Unversioned npx follows latest, not next.
Architecture
Plugin-first
Models, tools, skills, sessions, sandboxes, storage, loops, scheduling, and the UI are Cordis plugins. Compose them in configuration.
The verified release
Official developer preview on npm and the published source tree. Commands on this site are shown as text, not outbound links.
Official developer preview
First public preview 13 August 2026. npm next is 0.1.2-rc.1. npm latest is still 0.1.1-rc.2 (21 Aug 2026).
MIT licensed source
0.1.x packages. Inspect, modify, and self-host. Early 0.0.1-rc packages used BSD-3-Clause.
Everything is a plugin
Cordis installs and resolves plugin dependencies. You do not edit DeepSeek Harness source to change the stack.
Why the harness matters more than another coding demo
Runtime authors, operators, eval teams, and preset builders run dsh because capabilities live in plugins, and every run leaves a Trajectory record.
Workspace context
The agent reads the workspace you point at. Keep it disposable. workspace-write plus ask is the usual pin.
Tool execution
Standard mode ships file editing, shell, file and web search, skills, planning, goals, subagents, and workflows.
Trajectory
Append-only session log: prompts, reasoning, tool calls, subagent scheduling. Resume, fork, search, and replay.
Four modes
Standard, Code / PTC, Minimal, and Creator. One runtime. Full table on the Features page.
How a coding agent harness works
DeepSeek Harness keeps the model in the environment: workspace, tools, session log, then plugins you can recombine.
01
Ground the agent in the workspace
Point dsh at a disposable workspace. Plugins load models, tools, and session state before the model proposes changes.
02
Plan, call tools, and edit
Standard mode searches, reads, patches, and runs a shell. Code / PTC can combine multi-step tool work in one TypeScript program.
03
Verify against the session log
Trajectory records prompts, reasoning, tool calls and results. Resume, fork, search, and replay use the same stream.
04
Compose the next capability as a plugin
Creator mode inspects the live runtime and loads Cordis plugins in memory before you write a Profile.
Why this release matters
0.1.2-rc.1 is still a developer preview. The useful part is a readable plugin runtime you can pin, inspect, and self-host.
Agents need a harness
A model card is not a runtime. Plugins cover tools, sessions, sandboxes, and the local Web UI.
Long loops need a log
Trajectory keeps an append-only record. That is how you resume a turn and see the exact tool payload.
Owning the harness owns the stack
Swap model, tool, or sandbox plugins in configuration. You review what you install.
What to watch next
Preview stability
Pin @deepseek-ai/[email protected]. Unversioned npx follows latest (0.1.1-rc.2), not next.
Local interface
Web UI on 127.0.0.1:3080. Port 3080 is often reserved by Hyper-V, WSL2, or Docker.
Plugin contracts
The README says contracts can move before a stable. Community topic tags are discovery, not endorsement.
Sources used for this guide
Official release materials on this site. Commands and repository paths are shown as text.
Download
DeepSeek Harness developer preview
0.1.2-rc.1 packages, integrity notes, and platform buttons.
Source tree
deepseek-ai/deepseek-harness
Published repository path. Clone is shown as text on this page.
npm
@deepseek-ai/dsh
CLI package. latest 0.1.1-rc.2. next 0.1.2-rc.1. shasums on the download page.
Features
Runtime map
Cordis plugins, Trajectory, four modes, and sandbox policy.
Guides
Troubleshooting
Windows ACL, port 3080, pnpm load order, and upgrade titles.
Trust
Trust and safety
Legal usage policy. Not a security audit. You review plugins you load.
Questions people are asking about DeepSeek Harness
Does DeepSeek Harness cost money?+
No. The developer preview is MIT-licensed. You can read, change, and host it yourself. Early 0.0.1-rc packages used BSD-3-Clause; current 0.1.x packages are MIT.
Can I run DeepSeek Harness on Windows 11?+
Yes, with Node.js ^22.19.0 or >=24.0.0. The Windows sandbox uses an ACL restricted-token backend. Known issues include C:\Windows\Temp ACL lockouts, workspaces owned by BUILTIN\Administrators, and port 3080 reserved by Hyper-V, WSL2, or Docker.
Is DeepSeek Harness itself a model?+
No. It is the runtime around models: plugins for tools, sessions, sandboxes, storage, loops, scheduling, and the Web UI. Model IDs and API prices ship separately.
Why do scanners flag dsh?+
dsh is an npm CLI, not a Windows installer. Heuristic scanners sometimes flag Node processes that spawn shells. Check the published shasum for the version you pinned, such as fef213043313affc36ca2226d2637ad483b5e3f6 for 0.1.2-rc.1.
Get the preview
Download DeepSeek Harness
Windows 10/11, macOS, and Linux through Node.js. Package URL buttons live on the download page.