{"slug": "small-python-v0-4-0-close-to-cpython-speed", "title": "Small Python v0.4.0: Close to CPython Speed", "summary": "Small Python v0.4.0, released on GitHub by developer soasme, now runs at 0.98x–1.1x of CPython speed, up from 1.3x–1.5x slower, after a single Claude Code session with /remote-control enabled was used to benchmark and optimize the project. The author said the agent found and fixed performance opportunities over a day of work, and that after he supplied a few ideas it closed the remaining gap. The release matters as a demonstration of an AI coding agent iterating on a language implementation until it approaches CPython performance.", "body_md": "# Small Python v0.4.0: Close to CPython Speed\n\nThis is a follow-up to the [Small Python](https://www.julin.ai/2026/10/28/small-python-project/) idea. I burned one more day of tokens to benchmark it and improve the performance. The setup is the same: one single Claude Code session, with `/remote-control` enabled so that I can prompt it while I’m out. In the morning I attended a local farm event, and in the afternoon we went trick-or-treating for Halloween.\n\nThe agent is capable of finding opportunities and fixing them correctly. Often it can run a few hours before it prompts me with more potential things to fix. I generally just ask it to continue.\n\nAt one point it stopped and claimed it wouldn’t gain much more, while it was still 1.3x–1.5x slower than CPython. I gave it a few ideas, and now it runs at 0.98x–1.1x of CPython.\n\nIn the end, I’m more than happy to ship a new version: [Small Python v0.4.0](https://github.com/soasme/small-python).", "url": "https://wpnews.pro/news/small-python-v0-4-0-close-to-cpython-speed", "canonical_source": "https://julin.ai/2026/10/31/small-python-v0-4-0/", "published_at": "2026-10-30 11:00:00+00:00", "updated_at": "2026-10-31 09:49:24.212801+00:00", "lang": "en", "topics": ["ai-agents", "developer-tools", "ai-tools"], "entities": ["Small Python", "CPython", "Claude Code", "soasme", "GitHub"], "also_reported_by": [], "alternates": {"html": "https://wpnews.pro/news/small-python-v0-4-0-close-to-cpython-speed", "markdown": "https://wpnews.pro/news/small-python-v0-4-0-close-to-cpython-speed.md", "text": "https://wpnews.pro/news/small-python-v0-4-0-close-to-cpython-speed.txt", "jsonld": "https://wpnews.pro/news/small-python-v0-4-0-close-to-cpython-speed.jsonld"}}