pwasm 0.2a0
Simon Willison shipped pwasm 0.2a0, a pure-Python WebAssembly engine largely improved by Claude Opus 5.5.
Simon Willison released pwasm 0.2a0, his pure-Python WebAssembly engine, after leaving it untouched since January. He asked Claude Opus 5.5 to evaluate the project, support MicroPython and micro JavaScript experiments, and improve speed. After 42 commits with minimal follow-up, it handles almost the entire WASM specification, and the PyPI wheel bundles working WASM builds of MicroPython and QuickJS.
- pwasm is a pure-Python WebAssembly engine, originally vibe-coded in January.
- Claude Opus 5.5 produced 42 commits with little follow-up prompting.
- It now covers almost the full WASM spec and ships MicroPython and QuickJS wheels.
- Vendors
- Anthropic
- Products
- pwasmMicroPythonQuickJS
- Organizations
- PyPI
- AI models
- Claude Opus 5.5
From the original article
Release: pwasm 0. 2a0 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.
simonwillison.net
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