Show HN: jsrun – Isolated JavaScript Runtime in Python via Embedded V8 • Hacker News Board

Post by imfing » Mon, Nov 17, 2025, 6:06 PM UTC

Hi HN! I built jsrun, a Python library that embeds the V8 (https://v8.dev) engine to run JavaScript inside Python

Python does not have great options for sandboxed or isolated code execution, and I was hoping for something similar to the Cloudflare Workers model that provides lightweight isolates

jsrun provides: - a fully isolated JavaScript runtime backed by V8 - each runtime spins up a V8 isolate in built with Rust/PyO3, shipped as wheels with no extra dependencies

It would be good for cases like code playground, user scripting, AI generated code execution, or anywhere that needs a JS runtime inside a Python application

Would love any feedback, ideas!

Show HN: jsrun – Isolated JavaScript Runtime in Python via Embedded V8
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