I got a WebAssembly build of this working and fired up a web playground for trying it out: https://simonw.github.io/research/monty-wasm-pyodide/demo.ht...

It doesn't have class support yet!

But it doesn't matter, because LLMs that try to use a class will get an error message and rewrite their code to not use classes instead.

Notes on how I got the WASM build working here: https://simonwillison.net/2026/Feb/6/pydantic-monty/