Monty v1: open-source Python sandbox starts in 1ms, runs 10k scripts in 674ms
samuelcolvin · x · 2026-09-26
Samuel Colvin (creator of Pydantic) released Monty v1, an open-source Python sandbox that starts in 1 millisecond instead of 1.5 seconds — he ran 10k sandboxed scripts in 674ms, a task a cloud sandbox would need >3 hours for. Removing the biggest drawback of letting agents write code.
Key points:
- Installable via PyPI, npm, or Crates; fully open source, managed platform coming soon with design partners wanted
- Supports long-lived sessions: Monty can be dumped and resumed at any external function call
- Already powering temper's Python REPL, where agents compose temper. API calls — code flexibility with rigorous process, no unrestricted machine access or heavyweight sandbox
Related event: Pydantic Creator Open-Sources Monty, a Python Sandbox with 1ms Startup(5 posts)→
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