Sandboxed Python in the Browser with Pydantic's Monty

Recently, Simon Willison shared research on running Pydantic's Monty in WebAssembly. Monty is a minimal, secure Python interpreter written in Rust, designed specifically for safely executing code generated by LLMs. The key breakthrough here is the ability to run Python code with microsecond latency in a strictly sandboxed environment, either on the server (via Rust/Python) or directly in the browser (via WASM). I've put together a demo project that explores both the Python integration and the WebAssembly build. View Code What is Monty? Monty is a subset of Python implemented in Rust. Unlike Pyodide or MicroPython, which aim for full or broad compatibility, Monty is built for speed and security. It provides: Restricted Environment : No access to the host file system or network by default. Fast Startup : Ideal for "serverless" or "agentic" workflows where you need to run small snippets of code frequently. Rust Foundation : Leveraging Rust's safety and performance. Running it in the Brows