dspy-monty-interpreter

DSPy CodeInterpreter implementation using Monty, a secure Python interpreter written in Rust.

The Monty team points out, "This project is still in development, and not ready for the prime time." It uses a small subset of the standard library (sys, os, typing, asyncio, re, datetime, json) and can't yet define classes or use match statements.

That said: Monty is fast. For many RLM use cases, Monty is my daily driver.

Installation

pip install dspy-monty-interpreter

Usage

import dspy
from dspy_monty_interpreter import MontyInterpreter

interpreter = MontyInterpreter()
rlm = dspy.RLM("context -> answer", interpreter=interpreter)
result = rlm(context="What is 2 + 2?")

Standalone usage

from dspy_monty_interpreter import MontyInterpreter

interp = MontyInterpreter()

# Basic execution
interp.execute("x = 42")
interp.execute("print(x + 8)")  # returns "50"

# State persists across calls
interp.execute("def double(n):\n    return n * 2")
interp.execute("double(21)")  # returns "42"

# With tools
def lookup(key: str) -> str:
    return "some value"

interp = MontyInterpreter(tools={"lookup": lookup})
interp.execute('result = lookup(key="foo")\nprint(result)')

Why Monty?

• Fast: Microsecond startup (no subprocess, no WASM bootstrap)
• Secure: No filesystem, network, or environment access by default
• Lightweight: Pure Rust, no Deno/Pyodide dependency