---
title: Coding Environment Server
emoji: 💻
colorFrom: gray
colorTo: indigo
sdk: docker
pinned: false
app_port: 8000
base_path: /web
tags:
- openenv
---

Coding Environment

A Python code execution environment that runs arbitrary Python code and returns results. Perfect for testing code execution infrastructure and demonstrating environment usage patterns.

Quick Start

The simplest way to use the Coding environment is through the CodingEnv class:

from envs.coding_env import CodeAction, CodingEnv

try:
    # Create environment from Docker image
    coding_env = CodingEnv.from_docker_image("coding-env:latest")

    # Reset
    result = coding_env.reset()
    print(f"Reset complete: exit_code={result.observation.exit_code}")

    # Execute Python code
    code_samples = [
        "print('Hello, World!')",
        "x = 5 + 3\nprint(f'Result: {x}')",
        "import math\nprint(math.pi)"
    ]

    for code in code_samples:
        result = coding_env.step(CodeAction(code=code))
        print(f"Code: {code}")
        print(f"  → stdout: {result.observation.stdout.strip()}")
        print(f"  → exit_code: {result.observation.exit_code}")

finally:
    # Always clean up
    coding_env.close()

That's it! The CodingEnv.from_docker_image() method handles:

• Starting the Docker container


• Waiting for the server to be ready


• Connecting to the environment


• Container cleanup when you call close()




Building the Docker Image



Before using the environment, you need to build the Docker image:



From project root

docker build -t coding-env:latest -f src/envs/coding_env/server/Dockerfile .





Environment Details





Action


CodeAction: Contains a single field

• code (str) - The Python code to execute




Observation


CodeObservation: Contains the execution results

• stdout (str) - Standard output from code execution


• stderr (str) - Standard error from code execution


• exit_code (int) - Exit code (0 for success, non-zero for errors)




State


CodeState: Tracks execution state

• episode_id (str) - Unique identifier for the episode


• step_count (int) - Number of steps taken


• last_exit_code (int) - Exit code from the last execution




Advanced Usage





Connecting to an Existing Server



If you already have a Coding environment server running, you can connect directly:



from envs.coding_env import CodingEnv

Connect to existing server

coding_env = CodingEnv(base_url="<ENV_HTTP_URL_HERE>")

Use as normal

result = coding_env.reset()
result = coding_env.step(CodeAction(code="print('Hello!')"))



Note: When connecting to an existing server, coding_env.close() will NOT stop the server.



Development & Testing





Running the Full Example



Run the complete example that demonstrates the full workflow:



python3 src/envs/coding_env/client/example_usage.py



This example shows:

• Creating an environment from a Docker image


• Resetting and executing code through the environment


• Automatic cleanup with close()

Project Structure

coding_env/
├── README.md              # This file
├── models.py              # Action, Observation, and State models
├── client/
│   ├── coding_env_client.py  # CodingEnv client implementation
│   └── example_usage.py      # Usage examples
└── server/
    ├── python_codeact_env.py  # Core environment logic
    ├── app.py                 # FastAPI application
    ├── transforms.py          # Observation transforms
    ├── Dockerfile             # Container image definition
    └── README.md              # Server-specific documentation