I've had lots of fun with WASM Python in the browser - a few of my experiments with that are:

- https://lite.datasette.io - my Datasette app in a browser

- https://simonw.github.io/research/pyodide-asgi-browser/datas... is a new, improved version of that using Service Workers that's still a little experimental - notes here: https://simonwillison.net/2026/May/30/pyodide-asgi-browser/

- https://tools.simonwillison.net/micropython runs a MicroPython playground in the browser via WebAssembly

My use-cases for server-side WASM Python are described here: https://simonwillison.net/2026/Jun/6/micropython-in-a-sandbo... - basically I want to offer end-user customization features that run custom code without buggy or malicious code crashing my app or leaking their data.

Running arbitrary untrusted code safely is pretty easy nowadays, so long as the code is written in Javascript and you want to run it in a browser. It's only a little harder if the code is written in another language but targets WASM and browser APIs, or if you want to run your WASM inside of NodeJS, and there's even good support for running Python in a browser or Node.

Once you get away from running in a JS environment or away from code that's written with the intention of running in a WASM sandbox, if you don't want to have to modify the code for your environment then you're going to start having problems. This looks like a good step for anyone wanting to run arbitrary Python outside of a browser environment.

For me it is a tool I avail to an LLM so that it can provide correct answers to a certain category of questions, instead of hallucinating nonsense.

The idea is to expose it as a tool to your LLM agent so it can run calculations on its own initiative.