Quickstart: Run DeepSeek Harness in 5 Minutes — the Fastest dsh Guide

Install: two commands

DeepSeek Harness (dsh) needs Node.js and nothing else. The shortest path:

npm install -g @deepseek-ai/dsh
dsh --profile web

The first line installs the CLI globally; the second starts the harness with the web profile and opens the Web UI in your browser.

Don't want a global install? The one-shot equivalent:

npx @deepseek-ai/dsh web

Anything breaks along the way? Check github.com/deepseek-ai/deepseek-harness — the README and issues live there, and the README is the authority on the exact supported Node.js version.

The API key, or not

On the web page, paste your DeepSeek API key and you're in. If your machine already has the key in an environment variable, dsh picks it up — so skip that step entirely.

The harness is the body; the model is the brain. If you'd rather use another model, any OpenAI-compatible endpoint works — configure it in the UI settings (see What is DeepSeek Harness?).

Before the first task

One thing is worth sorting out first: start dsh from the folder you want the agent to work in. The default sandbox only lets it touch that workspace, so the launch directory is also a safety boundary.

Your first task

The Web UI opens on a chat. Describe the outcome you want, not the keystrokes — the agent plans its own steps. Good first tasks:

• "Summarize the TODOs in this repo and propose a plan to finish them."
• "Fix the failing tests in this project and run them to confirm."
• "Explain how this codebase is structured, as a short document."

Watch what happens: the agent may ask a clarifying question, propose a plan and wait for approval, then start making tool calls. The session log records everything the model sees, which is why you can resume or fork the session later.

If a risky operation comes up — writing outside the workspace, network calls, running unfamiliar commands — the harness will ask before doing it. That is the approval system working, not a bug.

Picking a mode

The mode selector at the top of the UI picks the session's Agent Preset. For your first run, leave it on Standard. The four modes:

A session locks its preset once it has content, so switch modes before you start typing.

After the first session

• Sessions are resumable. Close the tab, come back, and the event log lets you resume, fork, search and replay.
• "Installing" a plugin is editing config, not a package-manager command. Each plugin's README documents its own install line; read Installing plugins you can trust before your first one.
• Profiles, patches and presets are how the harness gets assembled around you — the configuration guide explains the stacking order. The patch layer is where dsh really diverges from other agents: sub-agents, conditional rules, permissions, UI replacement — all of it is config.

If it doesn't run

• Node.js version — the most common first-run failure; check the official README's supported version.
• No model response — check your API key in the UI settings, and that your machine can reach the provider's endpoint.
• Commands being refused — that is the sandbox or approval policy; either widen the sandbox deliberately (see the safety guide) or work inside the workspace.

Where next

• What is DeepSeek Harness? — the concepts behind what you just ran
• Profiles, patches & presets — make the harness yours
• Browse plugins — the fastest way to see what "everything is a plugin" means in practice