# DeepSeek Harness

Compose secure AI agents from replaceable plugins, tools, and runtimes

An open-source, plugin-native agent runtime from DeepSeek AI with a CLI, Web UI, Python SDK, tool registry, persistent sessions, sandboxing, and approval policies.

## Overview

- **Website**: https://deepseek.com/harness/
- **Docs**: https://deepseek-harness.github.io/deepseek-harness/en/guide/quickstart
- **GitHub**: https://github.com/deepseek-ai/deepseek-harness
- **License / Pricing**: Open Source
- **Directory Entry**: https://agentaccess.dk/enablers/deepseek-harness

## About

DeepSeek Harness is a composable runtime for building and operating agents that can inspect files, edit workspaces, execute shell commands, call structured tools, delegate work, and maintain plans. Its Cordis architecture implements models, tools, skills, sessions, storage, sandboxes, scheduling, the agent loop, and user interfaces as replaceable plugins coordinated through typed services and events. Sandbox backends, scoped tool restrictions, guarded execution pipelines, and configurable approval policies help constrain filesystem, shell, and network operations.

## Key Features

- Plugin-native Cordis architecture for replacing models, tools, sessions, storage, sandboxes, loops, and user interfaces
- CLI profiles, local Web UI, headless execution, and an embeddable Python SDK
- Schema-validated model-facing tool registry with scoped allowlists, restrictions, cancellation, and execution policies
- Persistent agent sessions with append-only logs for tool calls, context injection, replay, recovery, and branching
- Filesystem and shell capabilities protected by sandbox backends and configurable approval policies
- Composable profiles and bundles for distributing custom agents and third-party integrations without modifying the core

## Danish System Application Recipes

### Build a DAWA address-validation agent
Create a scoped tool plugin that queries the public DAWA address API, validates the returned JSON, and exposes normalized Danish addresses to the model.

```bash
export DEEPSEEK_API_KEY="sk-..."\nnpx @deepseek-ai/dsh --profile headless "Use curl to query https://api.dataforsyningen.dk/adresser?q=Rådhuspladsen%201 and return canonical address as JSON."
```

### Create a guarded CVR company lookup profile
Package an organization-approved CVR client as a schema-validated Harness tool, keeping credentials outside model context.

```bash
npx @deepseek-ai/dsh web --patch ./profiles/cvr/cordis.patch.yml
```

## Quickstart

```bash
# Requires Node.js\nnpx @deepseek-ai/dsh web\n\n# Open http://127.0.0.1:3080, select a workspace,\n# then add your DeepSeek API key under Settings → Models.
```

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Source: [AgentAccess Enablers](https://agentaccess.dk/enablers/deepseek-harness)