Python Workers Examples

This is a collection of examples for writing Cloudflare Workers in Python. Use these examples to learn how Python Workers work.

Get started

1. git clone https://github.com/cloudflare/python-workers-examples
2. cd 01-hello
3. npx wrangler@latest dev
4. Press the b key to open a browser tab, and make a request to your Worker

You can run npx wrangler@latest dev in any example project directory to run a local development server using Wrangler, the CLI for Cloudflare Workers. This local development server is powered by workerd, the open-source Workers runtime.

Need to deploy your Worker to Cloudflare? Python Workers are in open beta and have a few limitations.

The examples keep development tooling in the dev dependency group. webtypy is typing-only and is not a runtime dependency; the Workers runtime SDK supplies the Worker types. Bundling webtypy needlessly invokes the legacy Pyodide package installer, which fails with newer pip/urllib3 versions.

Engineering notes

• Lessons learned: dated runtime and test-harness findings.
• Shared engineering guidance: reusable diagnosis, testing, toolchain, and merge practices.
• Ruff rollout retrospective: cross-project evidence, completed scope, and remaining coverage gaps.

Examples

• 01-hello/ — the most basic Python Worker
• 02-binding/ — shows how bindings work in Python Workers. Put a key into Workers KV, and then read it.
• 03-fastapi/ — demonstrates how to use the FastAPI package with Python Workers
• 04-query-d1/ - shows how to query D1 with Python Workers
• 05-langchain/ — demonstrates how to use the LangChain package with Python Workers. Currently broken.
• 06-assets/ — An example with an assets binding.
• 07-durable-objects/ — An example with storing state in a Durable Object.
• 08-cron/ — shows a simple cron job.
• 09-workers-ai/ makes a call Workers AI to run inference on Cloudflare's Global Network.
• 10-workflows/ — shows a durable Workflows example.

Open Beta and Limits

• Python Workers are in open beta. You can use packages in your Workers by using the pywrangler tool.
• You must add the python_workers compatibility flag to your Worker while Python Workers are in open beta.

We’d love your feedback. Join the #python-workers channel in the Cloudflare Developers Discord and let us know what you’d like to see next.

License

The Apache 2.0 license.