{"data":{"slug":"monty","name":"Monty (Pydantic)","tagline":"MIT in-process Rust Python sandbox — OSS Monty only","category":"agents","categoryName":"AI Agents","url":"https://github.com/pydantic/monty","github":"https://github.com/pydantic/monty","pricing":"open-source","hook":"Monty is Pydantic’s open in-process Rust Python sandbox — run untrusted Python beside the agent without spinning a whole VM SaaS for every eval.","whatsGood":"MIT (pydantic/monty). OSS Monty only: `pydantic-monty` / `@pydantic/monty` / crates. Full Monty commercial is a separate product and is not required for the OSS bar. In-process Rust-backed Python sandbox aimed at agent tool runs and eval harnesses.","theCatch":"★8499 in about 41 weeks (~207 a week): judge it on the sandbox shape, not the star count. Vs E2B / AIO Sandbox / CubeSandbox: those are hosted Firecracker seats, broader sandbox/browser/MCP runtimes, or self-hosted RustVMM/KVM density — Monty’s catch is in-process Rust Python sandbox from Pydantic, not a sandbox SaaS seat. Do not confuse OSS Monty packages with Full Monty commercial; pin the MIT crates/npm/PyPI names.","verdict":"MIT in-process Python sandbox when agents need Pydantic Monty OSS — not E2B/AIO/CubeSandbox cloud or KVM seats; ignore the ★ spike.","addedAt":"2026-10-01","featured":false,"domain":"AI Agents","subSpecialty":"Orchestration","subcategory":"Orchestration","tags":["self-host","permissive","evals","sandbox","active"],"capabilities":["sandbox","python","rust"],"surfaces":["Self-host","Hosted"],"ecosystem":["Rust","Python","Multi-platform"],"licenseModel":"OSS/MIT","githubStars":8719,"starsPerWeek":49,"access":"free","archived":false,"repo":{"createdAt":"2023-05-28","pushedAt":"2026-10-18","license":"MIT","archived":false,"checkedAt":"2026-10-19"}},"related":[{"slug":"claude-code","name":"Claude Code","tagline":"Terminal-first coding agent with deep repository context"},{"slug":"cursor","name":"Cursor","tagline":"The AI-first code editor that understands your codebase"},{"slug":"devin","name":"Devin","tagline":"Autonomous AI engineer for defined engineering tasks"},{"slug":"stagehand","name":"Stagehand","tagline":"AI-native browser automation that mixes code and natural language"},{"slug":"browser-use","name":"Browser Use","tagline":"Open-source framework for LLM-driven browser agents"}],"links":{"self":"/api/gems/monty","html":"/gems/monty","markdown":"/gems/monty.md","category":"/api/gems?category=agents","categoryPage":"/stacks/agents"}}