Running Python code in a sandbox with MicroPython and WASM

Simon Willison has released micropython-wasm, an alpha package that runs Python code safely in a sandboxed environment using MicroPython compiled to WebAssembly. The sandbox provides memory and CPU limits, controlled file and network access, and support for host function interactions—addressing long-standing security concerns with his plugin systems in Datasette, LLM, and sqlite-utils. He chose WebAssembly for its proven security model and clean Python integration, avoiding the complexity and maintenance issues of other sandboxing approaches.