I forced Claude to play Tetris in Emacs

In plain words

This project demonstrates an elisp-eval MCP (model context protocol) that allows AI language models to execute Lisp code within a live Emacs session via emacsclient. The tool functions as a persistent REPL where state persists between calls, giving AI access to Emacs's full API—including buffers, files, subprocesses, and UI features. The creator used Tetris as a stress test to showcase the capability, but the same MCP can control any Emacs tool like Magit, Org, or Dired without additional glue code. It's designed for developers exploring AI-driven Emacs automation.

written from the facts on this page · September 2026

From the sources

In the maker’s words, at launch

The point of this seemingly useless exercise was to stress-test my elisp-eval MCP https://github.com/agzam/death-contraptions/tree/main/tools/... AI hands it a string of Lisp, it runs inside live Emacs session, poking into it via emacsclient. Behaves like a REPL the LLM can drive - state persists between the calls. Emacs is a Lisp machine. Buffers, files, network, subprocesses, games, major modes, the UI itself: every feature is already an elisp function. Hand an LLM a way to run arbitrary elisp and it inherits the entire Emacs API for free. No per-task glue code required. The same MCP can drive Magit, Org, Eshell, Dired, eww, or anything else someone ever wrote in elisp. Tetris is just to make the point.

• MS
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• IW
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• IC
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• TI
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• CR
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• E3
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