pwasm 0.2a0

AI introduction

Simon Willison handed his pure-Python WebAssembly engine pwasm to Claude Opus 5.5, and after 42 commits it released version 0.2a0. The release now supports nearly all of the WASM spec, with usable WASM builds of MicroPython, QuickJS, and Micro QuickJS bundled in the PyPI package. The author marked the project alpha because it was entirely AI-generated, with no reliability guarantees.

Article · English

pwasm is one of my folly projects - an entirely vibe-coded pure Python WebAssembly engine that I built in January during my first bout of AI mania.

I hadn't touched it since January, so I decided to let Claude Opus 5.5 loose on it and see if it could make any significant improvements:

Evaluate current state of pwasm - then consider what it would take to get the MicroPython and micro JavaScript experiments from the research repo working under it - and what it would take to speed it up

42 commits later (with minimal follow-up prompting) it now handles almost all of the WASM specification, and the wheel from PyPI bundles working WASM builds of MicroPython, QuickJS and Micro QuickJS.

I wouldn't trust this thing at all - hence the alpha version tag - but it's interesting seeing how today's models can improve on the work of models from 10 months ago.

Source: Simon Willison · simonwillison.net