backyard 0.1.0

Fast Python sandboxes for AI agents.

Backyard

Fast Python Sandbox for AI agent harnesses.

backyard supports transparent execution of Python code using either:

• Pydantic-Monty: an ultra-fast, minimal Python interpreter
• a container engine (Docker or Podman): full-featured Python support

Getting started

Installation

Using uv (recommended):

uv add backyard

Or, with pip:

pip install backyard

Python API

from pprint import pprint

from backyard import Sandbox

sandbox = Sandbox()

code = """
print("hello from the sandbox! 🏖🏰")
"""

result = sandbox.run(code)

pprint(result)

FAQ

Why did you create this?

Originally, I built the dual-engine sandbox for fine-tuning large language models using Reinforcement Learning from Verifiable Rewards (RLVR) with Group Relative Policy Optimization (GRPO). The sandbox provided an environment to safely execute model-generated code and generate rewards for training the model.

I then expanded the sandbox capabilities for use in the my-ai coding agent harness I am building.

Where does the name backyard come from?

The term "sandbox" refers to a controlled environment where untrusted code can be run safely.

In the physical world, a sandbox is a place where children explore and imagine as they create and shape the world around them. 🏖🏰

Where does one place a sandbox? In the backyard.