Feature Proposal: Add MCP (Model Context Protocol) Server Support to DeSmuME

[suhli]

Summary

I would like to propose adding support for an MCP (Model Context Protocol) server to DeSmuME.

I have already implemented a working prototype based on the current codebase here:

https://github.com/suhli/desmume/tree/mcp

This branch demonstrates that integrating an MCP server into DeSmuME is feasible with minimal intrusion into the existing architecture.

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Motivation

Adding MCP server support would allow:

• External AI agents (e.g., Cursor, LLM-based tools) to interact with the emulator programmatically
• Automated testing and scripted control of emulator state
• Memory inspection and manipulation through a standardized protocol
• Remote debugging and tooling integration
• Advanced automation workflows

This would make DeSmuME significantly more extensible for modern AI-assisted workflows.

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What the Prototype Implements

The mcp branch currently includes:

• Embedded MCP server inside DeSmuME
• Emulator state control (start, stop, reset, etc.)
• Memory read/write APIs
• Frame stepping support
• Basic structured command interface

The implementation is isolated and does not interfere with the normal UI execution path.

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Design Considerations

• The MCP server runs in a separate thread.
• Communication is JSON-based.
• The feature can be compiled optionally (e.g., via a build flag).
• No changes to core emulation logic were required.

If maintainers prefer, this can be:

• A compile-time optional feature
• A separate build target
• Or maintained as a plugin-style integration

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Questions for Maintainers

1. Would you be open to integrating MCP server support?

2. Should this be implemented as:

   • A core optional module?
   • A plugin?
   • Or kept as a separate fork?

3. Are there architectural constraints I should follow before preparing a PR?

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Next Steps

If there is interest, I can:

• Clean up the branch
• Split into smaller reviewable commits
• Add documentation
• Submit a formal PR

Looking forward to your feedback.