Coplay as a company offers three AI tools for Unity: Coplay, Coplay MCP, and Unity MCP.
If you've read our previous comparison of Coplay and Unity MCP, you might be wondering where Coplay MCP fits in. This post breaks down all three tools so you can choose the right one for your workflow.
In short:
- Coplay is our premium, in-editor AI assistant with the deepest Unity integration.
- Coplay MCP is an MCP server that exposes Coplay's full toolset to external tools like Claude Code, Cursor, and VS Code.
- Unity MCP is a lightweight, open-source MCP server with basic Unity tools.
| Category | Coplay | Coplay MCP | Unity MCP |
|---|---|---|---|
| License & Availability | Premium, proprietary | Proprietary (free for now) | MIT License (free) |
| Integration | Built directly inside Unity | External MCP server | External MCP server |
| MCP Host | Coplay can act as an MCP host | Requires external host (Claude Code, etc.) | Requires external host (Claude Code, etc.) |
| System Prompt | Fine-tuned for Unity | Relies on MCP host's prompt | Relies on MCP host's prompt |
| Context Awareness | Deep access (scenes, prefabs, hierarchy, visual) | Schema-defined tool access | File-level context |
| Learning & Adaptation | Continuously learns from your project | No project-specific learning | No project-specific learning |
| Toolset Size | 86 tools | 86 tools | 19 tools |
| Deferred Tool Loading | Yes | Yes | No |
| Visual Understanding & Feedback | Yes | Yes (limited) | No |
| Advanced Capabilities | 3D model gen, sprite gen, playbooks, pipelines, tab-completion | 3D model gen, sprite gen, playbooks | None |
| Best For | Unity creators who want maximum capability in-editor | Claude Code users who want Coplay's full toolset | Developers who want lightweight, open-source flexibility |
What Is Each Tool?
Coplay
Coplay is our premium AI assistant that lives directly inside the Unity Editor. It's a C# plugin that provides the deepest possible integration with your Unity project.
When you use Coplay, you're working with an AI that has:
- Full access to your Unity project context — open scenes, game objects, prefabs, scripts, and project structure
- Visual feedback — Coplay can see the results of its actions in Unity
- A fine-tuned system prompt specifically optimized for Unity development
- Continual learning from your specific project over time
Coplay is for users who want the most capable AI assistant and are willing to pay for it. It's designed to feel like a pair programmer who truly understands Unity.
Coplay MCP
Coplay MCP is our Model Context Protocol (MCP) server that exposes Coplay's 86 tools to any MCP-compatible host. Think of it as a bridge that lets external AI tools (like Claude Code) access the same powerful Unity tools that Coplay uses internally.
This means you get access to all 86 tools — creating game objects, managing scenes, modifying prefabs, and more — but through your preferred MCP host rather than through Coplay's UI.
One of the tools in Coplay MCP is called create_task, which will start up Coplay in Unity and execute a task as if it's a subagent.
However, running such tasks in Coplay consumes Coplay credits. Your MCP Client might choose to execute this tool in cases where Coplay is better suited for the task.
If you'd like to have completely free access, you can disable this tool and let your MCP Client work around it, which should be possible in most cases, just more time-consuming.
Coplay MCP is perfect if you already have an AI subscription (like Claude Code) and want to leverage it with the best possible bridge to Unity.
See our Coplay MCP documentation for setup instructions.
Coplay MCP is free for now. In the future we plan to charge $3/month per user for unlimited use of Coplay MCP, but while we're still in beta, it's free.
Unity MCP
Unity MCP is our open-source MCP server. It's a lighter-weight alternative with 19 essential tools for basic Unity operations.
Unity MCP is perfect if you:
- Prefer open-source tools you can modify and contribute to
- Want to add your own custom MCP tools
- Need a simple setup that covers the basics
- Already have an AI subscription (like Claude Code) and want to leverage it
Architecture Differences
The three tools have fundamentally different architectures:
Coplay runs as a native Unity Editor window written in C#. It has direct access to Unity's APIs and can observe changes in real-time. Its system prompt is specifically crafted for Unity workflows, and it maintains context about your project that improves over time.
Coplay MCP runs as an external Python server that communicates with Unity. It has access to all the tools Coplay has, but it relies on the MCP host's system prompt rather than a Unity-optimized one.
Unity MCP is also an external process, but it's intentionally minimal. With 19 tools focused on the most common operations, it's easier to understand, modify, and extend. The community drives its development direction.
One key distinction: Coplay can act as an MCP host itself. This means you can connect other MCPs (like Figma Converter for Unity or Blender MCP) to Coplay and manage your entire game development pipeline from within Unity.
Capabilities Comparison
Tool Count
- Coplay & Coplay MCP: 86 tools covering game objects, scenes, prefabs, scripts, materials, UI, input actions, packages, profiling, and more
- Unity MCP: 19 tools covering the essential operations
More tools isn't always better — the key is having the right tools with the right level of abstraction. We maintain internal benchmarks to ensure that changes to our toolsets actually improve task completion rates.
Context and Understanding
Coplay has the richest context awareness:
- Current open scene and hierarchy
- Prefab structures and script references
- Visual understanding of assets in your project
- Real-time feedback from Unity about action results
Coplay MCP provides schema-defined tool access. Your MCP host (like Claude Code) can execute any of the 86 tools, but it doesn't have the same deep context pipeline. Claude might need multiple tool calls to build up the context that Coplay has automatically.
Unity MCP offers file-level context. It's great for C# code generation and basic scene manipulation, but lacks visibility into prefab internals and project-wide relationships.
Advanced Features (Coplay Only)
Some capabilities are exclusive to Coplay [and Coplay MCP]:
- Pipeline recordings — Record your actions in Unity and replay them with AI assistance. See this example video.
- 3D model generation — Generate 3D models directly in Unity using providers like Meshy. [Also available in Coplay MCP]
- Parallel sprite generation — Generate multiple sprites simultaneously. [Also available in Coplay MCP]
- Playbooks — Pre-built workflows for creating standard game components. [Also available in Coplay MCP]
- Tab-completion — Autocomplete for hierarchy changes.
- Visual feedback — Coplay can see and verify the results of its actions. [Also available in Coplay MCP, but limited]
When To Use Each Tool
Choose Coplay if:
- You want the most powerful, integrated AI experience in Unity
- You frequently make changes in Unity (not just C# code)
- You value visual feedback and verification of AI actions
- You want features like pipeline recordings, 3D generation, and playbooks
- You're willing to pay for a premium tool
Choose Coplay MCP if:
- You already use Claude Code (or another MCP host) and love your workflow
- You want access to all 86 Coplay tools without switching to a different interface
- You want to run tasks across multiple Unity editors from a single terminal — see this example
- You prefer working from your IDE but need full Unity tool access
- You want a free tool that boosts your existing AI subscription such as Claude Code, Cursor, or VS Code
Choose Unity MCP if:
- You prefer open-source tools with MIT licensing
- You mainly work on C# code and need basic Unity operations
- You want to add custom MCP tools to fit your specific workflow
- You have strict privacy requirements that favor open-source solutions
- You're comfortable with technical setup and configuration
Conclusion
All three tools help you work more efficiently with Unity using AI. The right choice depends on your workflow preferences and requirements.
Benefits of Coplay
- Most capable and accurate for Unity tasks
- Visual feedback and understanding
- Fine-tuned system prompt and continual learning
- Advanced features (pipelines, 3D gen, playbooks)
- Easiest setup — one-click installation in Unity
Benefits of Coplay MCP
- Access to all 86 Coplay tools from your favorite MCP host
- Perfect for multi-editor workflows
- Integrates with existing Claude Code setups
Benefits of Unity MCP
- Lightweight and easy to understand
- Community-driven development
- Fully open-source and modifiable
- Fits environments with strict privacy requirements
If you have questions or want to discuss which tool is right for you, join us on Discord.