pydanticOfficial·8 Agent Skills Included

monty

Run AI-generated Python code safely in a fast Rust sandbox

Runs untrusted Python code written by AI agents inside a secure Rust-based sandbox. Blocks filesystem, network, and environment access while enforcing memory, time, and stack limits. Starts in microseconds instead of slow containers, and works from Python, JavaScript, or Rust. Supports snapshots, type checking, and controlled host function calls for safe agent workflows.

8,147|413

↗

npx skills add pydantic/monty --all -g -y

Available:

Gives the AI agent the project architecture, strict sandbox security rules, and cross-platform constraints it must follow when writing or reviewing code in this repository.

All Skills in This Repository (8)

Pure Emerald Level Indicators

📦 In Repo

pydantic

python-playground

Execute Python code in an isolated playground directory.

fastmod

Apply consistent pattern-based code replacements across a codebase using the fastmod tool.

fix-pr-comments

Reads, resolves, and replies to bot reviewer comments on GitHub pull requests.

review-usability

Tests idiomatic Python code against CPython and Monty to detect behavioral divergences.

review-general

Reviews branch diffs against the merge base for bugs, sandbox escapes, and documentation gaps.

review-security

Reviews branch diffs for sandbox escapes, memory errors, panics, and resource-limit bypasses.

review-verbosity

Rewrites verbose comments and docstrings added by a git branch into concise documentation.

writing-style

Rewrites technical prose to read like human documentation instead of LLM output.

Official

Intermediate

Frequently Asked Questions

FAQPage Schema

How to install Monty?▼

Run `npx skills add pydantic/monty --all -g -y` in your terminal to install all skills in this suite globally.

What is Monty used for?▼

Monty is a minimal Python interpreter written in Rust that safely runs code generated by AI agents. It replaces slow container sandboxes with microsecond startup times.

Is Monty safe for untrusted AI-generated code?▼

Yes. Monty blocks filesystem, network, and environment access by default, enforces memory and time limits, and runs code in isolated worker processes so crashes cannot harm your application.

Can I use Monty from Python or JavaScript?▼

Yes. Monty ships as the pydantic-monty package for Python, the @pydantic/monty package for JavaScript and TypeScript, and as Rust crates.

Does Monty support the full Python language?▼

No. Monty supports a practical subset of Python 3.14, including async code and common standard library modules, but not third-party packages, class inheritance, or match statements.