Cloudflare Python Workers Reach GA After Two-Year Preview, but Threading Stays Broken

Cloudflare has moved Python Workers to general availability, making Python a first-class language on its Workers platform alongside TypeScript. The runtime compiles Python to WebAssembly via Pyodide inside the V8-based workerd engine, letting FastAPI, Django and Flask apps talk directly to Workers AI, R2, D1, Hyperdrive, Durable Objects, Queues and Workflows. The tradeoff for that sandboxing: multiprocessing and threading don't work in the WebAssembly VM, so CPU-bound or thread-heavy Python workloads aren't a fit yet.

• GA announced September 21, 2026, two years after the original Python Workers preview
• Runs FastAPI, Django and Flask directly inside Workers, wired into R2, D1, Hyperdrive, Durable Objects, Queues and Workflows
• Local dev tool pywrangler (published as workers-py on PyPI) simulates the full stack, bundling a 123MB workerd binary via Pyodide/V8
• Two of the three credited engineers, Gyeongjae Choi and Hood Chatham, are Pyodide core maintainers, signaling deep upstream investment
• Caveat: both signals rely on Cloudflare's own announcement and a single independent analysis, so real-world limits beyond the documented threading/multiprocessing gap are still untested

Bottom line If you're building on Cloudflare Workers and want Python instead of TypeScript, this is now safe to adopt in production—just keep CPU-bound or multithreaded workloads elsewhere.