All 36 Dependencies
Every package monty depends on, ranked by repo health score.
Monty is a minimal, secure Python interpreter written entirely in Rust, purpose-built for one job: executing Python code produced by AI agents. Instead of spinning up Docker containers, spawning CPython subprocesses, or risking direct host execution, Monty runs a curated subset of Python inside a hermetic sandbox that boots in under one microsecond and gives developers precise control over every external call the code can make.
The interpreter implements its own AST-walking execution engine on top of Ruff's Python parser, meaning it has zero dependency on CPython or any C extension. Filesystem reads, environment variable lookups, and network calls are all routed through explicit host callbacks that developers register — everything else is blocked by default. Memory usage, stack depth, and wall-clock time can all be capped per-run with a typed `ResourceTracker` interface.
Monty ships as a Rust library, a Python package (`pydantic-monty`), and a JavaScript/TypeScript package (`@pydantic/monty`), each backed by the same Rust worker-pool runtime. The Python and JS bindings run Monty workers as isolated subprocesses, so even a memory-safety violation triggered by adversarial code kills only the worker — the host process stays alive and receives a `MontyCrashedError`. A WebAssembly build is also available for browser environments where subprocess isolation is impossible.
Built by the Pydantic team and designed to power code-mode in Pydantic AI, Monty represents a practical answer to programmatic tool calling: let the LLM write Python instead of issuing sequential JSON tool calls, execute that Python safely inside the agent loop, and handle the results with the same type-checked Python machinery you already use.
