Agents thatactually take action.

DeepSeek Harness is the open-source agent harness from DeepSeek. Everything is a plugin—giving agents clear, composable, and extensible capabilities.

Agent

Tool plugins

Model support

Data sources

Memory

Action loop

Keep agents working in the real world

Harness organizes environment understanding, tool use, and continuous execution into a composable, traceable runtime.

Models, tools, skills, sessions, sandboxes, storage, loops, scheduling, and UI are plugins that collaborate through Cordis.

Prompts, tool calls, sub-agent scheduling, and context injections share one session log for restore, fork, search, and replay.

Select, replace, or extend any agent capability at the configuration layer without changing Harness source code.

Move from a full coding agent to minimal benchmarking and custom mode creation.

A complete coding agent with file editing, Shell, file and web search, Skills, plans, goals, sub-agents, and workflows.

Includes every standard capability and lets the model compose multi-step tool operations in one TypeScript program.

Keeps only a persistent Shell and file editor for model benchmarking in a minimal environment.

Inspects the runtime, experiments with Cordis plugins, and composes new custom agent presets.

Install Node.js to run from npm; building from source also requires pnpm.

npx @deepseek-ai/dsh web

git clone https://github.com/deepseek-ai/deepseek-harness.git
cd deepseek-harness
pnpm install
pnpm run build
pnpm dsh web

Build a stronger agent ecosystem with DeepSeek Harness.