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I forced Claude to play Tetris in Emacs

I forced Claude to play Tetris in Emacs

by iLemming·Apr 11, 2026·13 points·3 comments
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AI Analysis

●●SolidWizardryNiche Gem

Gives LLMs raw Elisp eval access to drive Magit, Org, or Tetris without glue.

Strengths
  • •Stateful REPL persists context between calls, unlike stateless API wrappers.
  • •Exposes entire Emacs API to AI without custom integration per feature.
  • •Standard MCP protocol ensures compatibility with any client, avoiding vendor lock-in.
Weaknesses
  • •Arbitrary Elisp execution risks security, needing careful sandboxing or strict trust boundaries.
  • •Niche appeal limits usage to Emacs users; others lack immediate utility.
Target Audience

Emacs users, AI automation enthusiasts

Similar To

Continue.dev · Cursor · Emacs LSP

Post Description

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.

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