What happened
Cloudflare's Python Workers support is now generally available, leaving a two-year preview, according to Simon Willison. Willison writes that Cloudflare runs Python compiled to WebAssembly via Pyodide in its V8-based workerd runtime, and describes the release as a significant investment in the wider Python ecosystem. He notes the release announcement is credited to Gyeongjae Choi, Dominik Picheta, and Hood Chatham, with Gyeongjae and Hood both Pyodide core maintainers. [1]
Limits and local development
Willison reports documented limitations, most notably that multiprocessing and threading are non-functional in the WebAssembly VM. He also highlights the local development environment: the pywrangler tool (packaged as workers-py on PyPI) runs a full local simulation of Cloudflare's stack, including executing code with Pyodide in WebAssembly in V8 in a 123MB workerd binary, which for him ended up in node_modules/@cloudflare/workerd-darwin-arm64/bin/workerd. [1]
Sources
- Cloudflare Python Workers are now generally available
Simon Willison · Reporting · Sep 21, 2026
“Cloudflare Python Workers are now generally available”
“After a two year preview, Cloudflare's support for running Python code in their server-side Workers platform is now stable”