Introduction

The core design philosophy of DeepSeek Harness (DSH) is a plugin-based architecture. Unreal Engine 5.8 introduced the official ModelContextProtocol server. dsh-unreal-mcp is an adapter plugin designed to bring DSH’s UE adaptation capabilities to a practical boundary comparable to Epic’s Claude Code integration. It does not include UE engine code or a generic MCP client implementation; instead, it focuses on packaging, configuration, and context management.

Core Features

The plugin manages the Cordis plugin through DSH’s lifecycle and provides the following capabilities:

  • Cordis plugin management: managed by DSH’s load/unload lifecycle.
  • Built-in Unreal Skills:
    • unreal-mcp: Discover and invoke existing Unreal Editor Toolsets.
    • create-toolset: Author AI-callable C++ or Python Toolsets.
    • unreal-skill: In-editor guides for writing and registering UAgentSkill classes or project-specific Skill assets.
  • Context routing: Session-based .uproject and UE source tree detection, routing concise Unreal context through ctx.systemPrompt.context().
  • Read-only diagnostics: Inspect the connection, tool search, and ToolsetRegistry.

Installation

Before use, ensure the following environment requirements are met:

  • Unreal Engine 5.8 (with ModelContextProtocol and AllToolsets enabled)
  • A DeepSeek Harness compatible version 0.1.1-rc.2
  • Node.js 20 or newer, with pnpm accessible from dsh plugin
  • A disposable Unreal project for testing

Installation command:

dsh plugin --profile web add /absolute/path/to/dsh-unreal-mcp

If using a packaged tarball:

npm pack
dsh plugin --profile web add /absolute/path/to/dsh-unreal-mcp-0.1.0.tgz

Typical Usage

After installation, start the Unreal MCP server and DSH client, then use the diagnostic command to verify the connection.

  1. Start the Unreal MCP server: Run the following in the Unreal Editor console:
    ModelContextProtocol.StartServer 8000
  1. Start DeepSeek Harness:
    dsh --profile web
  1. Diagnose the connection: Run the diagnostic script from the project root:
    npm run diagnose -- --endpoint=http://127.0.0.1:8000/mcp --cwd="/absolute/path/to/MyGame/Content"

Notes and Security

  • Permission requirements: Unreal MCP has editor-level permissions. When performing tasks that modify state, you must use a disposable project with tested recovery points and retain matching tool results and the final editor state as evidence.
  • Security policy: Skills in the plugin guide the agent to issue UE calls sequentially, require explicit user authorization before making changes, and check UE state before retrying non-idempotent operations. The specific execution scheduling, retry, and sandboxing mechanisms are still handled by DSH.
  • License: The project code is under the MIT license. Adapted Epic Skill materials retain Epic’s MIT notice.

Plugin directory: dsh-unreal-mcp
Source repository: GitHub