What is DeepSeek Harness?

DeepSeek Harness (CLI name dsh) is DeepSeek AI's open-source agent runtime: tools, filesystem, sessions, a loop and a UI around a model. It is not a new model, and it is not the chat.deepseek.com product. The official design is “everything is a plugin,” powered by Cordis.

How do I install and start DeepSeek Harness?

Install Node.js, then run `npx @deepseek-ai/dsh web`. The Web UI defaults to http://127.0.0.1:3080. From source: clone, `pnpm install && pnpm run build && pnpm dsh web`. After boot, add a DeepSeek API key under Settings → Models and choose a workspace before sending a task.

Does DeepSeek Harness only work with DeepSeek models?

No. The official provider guide covers a DeepSeek key, catalog providers such as Anthropic and OpenAI, and custom OpenAI-compatible endpoints. Keys live in `$DSH_HOME/.credentials.yaml`; model changes apply on the next request without a restart.

How does DeepSeek Harness differ from Claude Code and Cursor?

Claude Code and Cursor are mature commercial coding-agent products. Harness is an MIT-licensed runtime still in developer preview: you can replace the model adapter, tools, sandbox and UI. Think of it as a take-apart agent chassis, not a finished IDE. The official README warns that compatibility-breaking changes will happen.

What are dsh, a profile, and a bundle?

`dsh` is the launcher. A profile is a named plugin composition (shipped templates: web and headless). A bundle is a patchable plugin layer: `dsh-base` owns models/tools/sandbox, `dsh-web-app` adds the browser UI, `dsh-headless` is a one-shot runner with no server. Your own overrides live in `cordis.patch.yml`.

Is it production-ready?

The official README is explicit: it is a developer preview, iterating rapidly, and there will be compatibility-breaking changes. Use it to learn the architecture, write plugins and experiment. Pinning core business flows to the current API is risky. The license is MIT.

DeepSeek HarnessDeveloper previewMIT

DeepSeek open-sourced the agent runtime

DeepSeek Harness (CLI name dsh) is not a new model, and it is not chat.deepseek.com. It is the layer around a model: tools, files, sessions, a loop, a UI. Official line: everything is a plugin.

Updated 2026-08-13. Numbers are a same-day snapshot of the official repo. No invented benchmarks.

38.6k

GitHub stars (snapshot)

3.0k

Forks (snapshot)

Developer preview

Official status

MIT

License

Open the GitHub repo Official site Start with the install guide

Three things people mix up

Chat product

chat.deepseek.com is the web chat. Use it for questions and copy.

Model API

deepseek-v4-pro / flash are models on the API. Your backend calls them.

Harness / dsh

The runtime that lets a model read a repo, run commands and swap plugins. This page is about that.

Founders

Only verified people pages, official X accounts, and interviews already on this site. Unverified personal accounts stay off.

Founder

Liang Wenfeng

DeepSeek founder

DeepSeek founder; shocked the world with restraint and open source

Profile

Interviews on this site

Lab official X: @deepseek_ai(Liang Wenfeng's personal account is unverified and not listed under his name)

Get it running

The official shortest path is one command. After boot you still need two things: an API key and a workspace. The composer stays closed until a workspace is selected.

npx @deepseek-ai/dsh web
# Web UI → http://127.0.0.1:3080
# Settings → Models → DeepSeek API key
# Choose workspace → send: Summarize this repository

Command and default port come from the official README and Web UI guide. Compatibility will change; trust the current repo docs.

A boot is four stacked layers

Do not picture Harness as a locked app. Boot stacks an empty list: base bundle, then web or headless, then your patch. Any layer can be swapped.

01
cordis.patch.yml
Your overlay: swap models, add plugins, change policy.
02
profile · web / headless
Which stack boots: a UI, or a one-shot runner with no server.
03
bundle · dsh-web-app
The browser app. Headless profiles do not stack this layer.
04
bundle · dsh-base
First layer of every profile: model adapters, tools, persistence, sandbox, credentials.

Tutorials

All tutorials

Beginner · 2026-08-13

DeepSeek Harness Quickstart: Boot the Web UI, Then Close One Repo Loop

Do not start by writing a plugin. Follow the official README: boot the dsh Web UI, add an API key, pick a workspace, then ask the agent to summarize the repo.

Intermediate · 2026-08-13

DeepSeek Harness Architecture: Why ‘Everything Is a Plugin’ Is Not a Slogan

Use the official architecture.md to explain profiles, bundles, the session log and turn/step. No package table dump — only where new behavior should attach.

Intermediate · 2026-08-13

Your First DeepSeek Harness Plugin: Mount It Before You Productize

Follow the official first-plugin tutorial through apply(ctx) and a Cordis overlay. No full step dump — only boundaries and what to do next.

Beside Claude Code and Cursor

Orientation only — not a ranked review. Harness license and architecture come from the official README and architecture.md; Claude Code and Cursor shapes come from their product pages. We have not run a shared eval, so we do not claim which is faster, more accurate or cheaper.

Product	License	Shape	Replaceability	Maturity (official)
DeepSeek Harness	MIT	Open agent runtime + Web UI / headless	Model, tools, session, loop and UI are plugins	Developer preview; breaking changes expected
Claude Code	Proprietary product	Terminal coding agent	Skills / hooks / MCP; core loop is closed	Generally available to developers
Cursor	Proprietary product	AI-native IDE	Rules, Skills, extensions; the editor is closed	Generally available to developers

Latest news

2026-08-13 · GitHub · deepseek-ai/deepseek-harness · Official
DeepSeek open-sources DeepSeek Harness (dsh): everything is a plugin
Official repo deepseek-ai/deepseek-harness is public: MIT license, developer preview, one-command `npx @deepseek-ai/dsh web`. Built on Cordis so the model adapter, tools, sessions and agent loop are all replaceable plugins.
2026-08-03 · South China Morning Post · Press
SCMP: DeepSeek invites open-source developers to test its upcoming harness
The report said DeepSeek was inviting testers for a harness layer that turns LLMs into executable agents, in the same narrative as V4's agentic work.

What DeepSeek Harness Is: The Layer Around the Model, Now Open Source

LaoJin's pick

38.6k ★ · 2026-08

DeepSeek Harness

DeepSeek's official open-source agent runtime: everything is a plugin, MIT licensed, one npx command for the Web UI. If you want to see how the layer around a model comes apart, this is the new repo to watch in August 2026.

FAQ

What is DeepSeek Harness?: DeepSeek Harness (CLI name dsh) is DeepSeek AI's open-source agent runtime: tools, filesystem, sessions, a loop and a UI around a model. It is not a new model, and it is not the chat.deepseek.com product. The official design is “everything is a plugin,” powered by Cordis.
How do I install and start DeepSeek Harness?: Install Node.js, then run `npx @deepseek-ai/dsh web`. The Web UI defaults to http://127.0.0.1:3080. From source: clone, `pnpm install && pnpm run build && pnpm dsh web`. After boot, add a DeepSeek API key under Settings → Models and choose a workspace before sending a task.
Does DeepSeek Harness only work with DeepSeek models?: No. The official provider guide covers a DeepSeek key, catalog providers such as Anthropic and OpenAI, and custom OpenAI-compatible endpoints. Keys live in `$DSH_HOME/.credentials.yaml`; model changes apply on the next request without a restart.
How does DeepSeek Harness differ from Claude Code and Cursor?: Claude Code and Cursor are mature commercial coding-agent products. Harness is an MIT-licensed runtime still in developer preview: you can replace the model adapter, tools, sandbox and UI. Think of it as a take-apart agent chassis, not a finished IDE. The official README warns that compatibility-breaking changes will happen.
What are dsh, a profile, and a bundle?: `dsh` is the launcher. A profile is a named plugin composition (shipped templates: web and headless). A bundle is a patchable plugin layer: `dsh-base` owns models/tools/sandbox, `dsh-web-app` adds the browser UI, `dsh-headless` is a one-shot runner with no server. Your own overrides live in `cordis.patch.yml`.
Is it production-ready?: The official README is explicit: it is a developer preview, iterating rapidly, and there will be compatibility-breaking changes. Use it to learn the architecture, write plugins and experiment. Pinning core business flows to the current API is risky. The license is MIT.

How this hub stays current

Append news to the head of HARNESS_NEWS in src/content/deepseek-harness.ts. Links, FAQ and the comparison table live in the same file. Tutorials, directory cards and picks stay in their append-only files and hang off this page by slug. Unverified numbers stay out.

Playbook: docs/deepseek-harness/PLAYBOOK.md