Gym Server

Expose any Gymnasium environment as an MCP (Model Context Protocol) server, automatically converting the Gym API (reset, step, render) into MCP tools that any agent can call via standard JSON interfaces.

Python 3.10+ License: MIT Test Coverage

Features

• 🎮 Works with any Gymnasium environment
• 🔧 Exposes gym operations via multiple protocols:
  • MCP (Model Context Protocol) over HTTP (/mcp, streamable-http)
  • HTTP/REST - FastAPI with Swagger UI (same server)
• 🚀 Simple API with automatic serialization and error handling
• 🤖 Designed for AI agent integration (OpenAI Agents SDK, LangChain, etc.)
• 🔍 Type safe with full type hints
• ♻️ Shared service layer for code reuse across protocols

Installation

pip install gym-mcp-server

Requirements: Python 3.10+

Quick Start

Combined HTTP server (REST + MCP)

Run a single server that exposes both REST endpoints and the MCP endpoint:

python -m gym_mcp_server --env CartPole-v1 --host localhost --port 8000
# REST docs: http://localhost:8000/docs
# MCP endpoint: http://localhost:8000/mcp

Programmatic Usage

from gym_mcp_server import GymHTTPServer

# One HTTP server exposing both REST + MCP (/mcp) for the same env instance
server = GymHTTPServer(env_id="CartPole-v1", render_mode="rgb_array")
# server.run(host="localhost", port=8000)

Available Tools

The server exposes these MCP tools:

• reset_env - Reset to initial state (optional seed)
• step_env - Take an action (required action)
• render_env - Render current state (optional mode)
• close_env - Close environment and free resources
• get_env_info - Get environment metadata
• sample_action - Sample a random action from the action space

All tools return a standardized format:

{
    "success": bool,  # Whether the operation succeeded
    "error": str,     # Error message (if success=False)
    # ... tool-specific data
}

Examples

You can use the server with any MCP-compatible client. Here's a simple example using the MCP Python client:

from mcp import ClientSession
from mcp.client.streamable_http import streamable_http_client

async with streamable_http_client("http://localhost:8000/mcp") as (read, write, _):
    async with ClientSession(read, write) as session:
        await session.initialize()
        
        # List available tools
        tools = await session.list_tools()
        print(f"Available tools: {[tool.name for tool in tools.tools]}")
        
        # Reset the environment
        result = await session.call_tool("reset_env", arguments={})
        print(f"Reset result: {result.content[0].text}")

Integration

OpenAI Agents SDK

Use the MCPServerStreamableHttp class to connect agents to gym environments:

from agents import Agent, Runner
from agents.mcp import MCPServerStreamableHttp

async with MCPServerStreamableHttp(
    name="Gym Environment",
    params={"url": "http://localhost:8000/mcp", "timeout": 10},
) as server:
    agent = Agent(name="GymAgent", instructions="...", mcp_servers=[server])
    result = await Runner.run(agent, "Play CartPole")

Documentation: OpenAI Agents SDK MCP Integration

Other Frameworks

Compatible with any MCP-compatible framework (LangChain, AutoGPT, custom MCP clients, etc.)

Configuration

Command Line Options

python -m gym_mcp_server --help

• --env: Gymnasium environment ID (required)
• --render-mode: Default render mode (e.g., rgb_array, human)
• --host: Host to bind (default: localhost)
• --port: Port to bind (default: 8000)

Troubleshooting

Environment-Specific Dependencies

Some environments require additional packages:

pip install gymnasium[atari]   # For Atari environments
pip install gymnasium[box2d]   # For Box2D environments
pip install gymnasium[mujoco]  # For MuJoCo environments

Python Version

Ensure you're using Python 3.10+:

python --version  # Should show 3.10 or higher

Development

For development and testing:

git clone https://github.com/haggaishachar/gym-mcp-server.git
cd gym-mcp-server
make install     # Install with dependencies
make check       # Run all checks (lint, typecheck, test)

See the Makefile for all available commands.

License

MIT License - see the LICENSE file for details.

Links

• GitHub Repository
• Gymnasium Documentation
• Model Context Protocol