pwasm 0.2a0
Simon Willison's Weblog (LLM / AI engineering) · Oct 1, 2026
Claim: Claude Opus 5.5 substantially improved a vibe-coded pure Python WebAssembly engine (pwasm) over 42 commits, enabling MicroPython and QuickJS to run under it with working PyPI builds.
Evidence: Release note: 42 commits; now handles "almost all of the WASM specification"; wheel from PyPI bundles working WASM builds of MicroPython, QuickJS, and Micro QuickJS. Author admits "I wouldn't trust this thing at all" and tagged it alpha.
Archive rationale
Self-authored folly project ("vibe-coded") with no quantified metrics, no production use case, author explicitly warns against trusting it, and entirely irrelevant to Timothy's agentic CC+Codex+Next.js/Supabase stack. Interesting as a Claude 5.5 demo but zero applicability, durability (likely a workaround for current model limits), or business value. Alpha stage and author distrust confirm DISCARD.