OpenEnv documentation

Reasoning Gym Environment

Hugging Face's logo
Join the Hugging Face community

and get access to the augmented documentation experience

to get started

Reasoning Gym Environment

An OpenEnv environment that integrates the Reasoning Gym library to provide single-step reasoning tasks. Each episode presents one question from a configurable dataset, the agent submits an answer, and receives a score.

Quick Start

The simplest way to use the Reasoning Gym environment is through the ReasoningGymEnv class:

from reasoning_gym_env import ReasoningGymAction, ReasoningGymEnv

try:
    # Create environment from Docker image
    env = ReasoningGymEnv.from_docker_image("reasoning_gym-env:latest")

    # Create a dataset with 10 leg_counting questions
    result = env.reset(
        dataset_name='leg_counting',
        seed=42,
        size=10
    )
    print(f"Question: {result.observation.question}")
    # Question: "How many legs does a cat have?"

    # Submit answer
    result = env.step(ReasoningGymAction(answer="4"))
    print(f"Score: {result.observation.score}")  # 1.0 (correct)
    print(f"Correct answer: {result.observation.correct_answer}")  # "4"
    print(f"Reward: {result.reward}")  # 1.0
    print(f"Done: {result.done}")  # True (single-step episodes)

    # Access dataset metadata if available
    if result.observation.dataset_metadata:
        print(f"Metadata: {result.observation.dataset_metadata}")  # Dataset-specific info

    # Get next question from same dataset
    result = env.reset()  # No params = reuse dataset
    print(f"Next question: {result.observation.question}")

    # Note: First reset() without params creates a default leg_counting dataset
    # with seed=42 and size=1000 for reproducible, out-of-the-box functionality

finally:
    # Always clean up
    env.close()

That’s it! The ReasoningGymEnv.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 the reasoning_gym_env directory
docker build -t reasoning_gym-env:latest -f server/Dockerfile .

Deploying to Hugging Face Spaces

You can easily deploy your OpenEnv environment to Hugging Face Spaces using the openenv push command:

# From the environment directory (where openenv.yaml is located)
openenv push

# Or specify options
openenv push --namespace my-org --private

The openenv push command will:

  1. Validate that the directory is an OpenEnv environment (checks for openenv.yaml)
  2. Prepare a custom build for Hugging Face Docker space (enables web interface)
  3. Upload to Hugging Face (ensuring you’re logged in)

Prerequisites

  • Authenticate with Hugging Face: The command will prompt for login if not already authenticated

Options

  • --directory, -d: Directory containing the OpenEnv environment (defaults to current directory)
  • --repo-id, -r: Repository ID in format β€˜username/repo-name’ (defaults to β€˜username/env-name’ from openenv.yaml)
  • --base-image, -b: Base Docker image to use (overrides Dockerfile FROM)
  • --private: Deploy the space as private (default: public)

Examples

# Push to your personal namespace (defaults to username/env-name from openenv.yaml)
openenv push

# Push to a specific repository
openenv push --repo-id my-org/reasoning-gym-env

# Push with a custom base image
openenv push --base-image ghcr.io/meta-pytorch/openenv-base:latest

# Push as a private space
openenv push --private

# Combine options
openenv push --repo-id my-org/reasoning-gym --base-image custom-base:latest --private

After deployment, your space will be available at: https://huggingface.co/spaces/<repo-id>

The deployed space includes:

  • Web Interface at /web - Interactive UI for exploring the environment
  • API Documentation at /docs - Full OpenAPI/Swagger interface
  • Health Check at /health - Container health monitoring
  • WebSocket at /ws - Persistent session endpoint for low-latency interactions

Environment Details

Episode Structure

Each episode is single-step:

  1. reset() returns a question
  2. step(answer) returns score and marks episode as done
  3. reset() without params gets next question from same dataset

Action

ReasoningGymAction: Contains the agent’s answer

  • answer (str) - The agent’s answer to the current question

Observation

ReasoningGymObservation: Contains the question or result

  • question (Optional[str]) - The current question (only in reset)
  • score (Optional[float]) - Score for the answer, 0.0 to 1.0 (only after step)
  • correct_answer (Optional[str]) - The correct answer (only after step)
  • dataset_metadata (Optional[Dict]) - Metadata from the reasoning gym dataset entry
  • done (bool) - Always True after step (single-step episodes)
  • reward (float) - Equal to score (0.0 to 1.0)

Reward

The reward equals the score returned by the dataset’s scoring function:

  • Correct answer β†’ score: 1.0
  • Incorrect answer β†’ score: 0.0 to 1.0 (dataset-dependent, may use partial credit)

Dataset Configuration

Simple Datasets

Use a single dataset with configuration:

result = env.reset(
    dataset_name='leg_counting',
    seed=42,
    size=10
)

Available datasets from reasoning_gym library:

  • leg_counting - Count legs of various objects
  • reverse_sort - Sort lists in reverse order
  • chess_state_eval - Chess position evaluation
  • And more (see Reasoning Gym documentation)

Composite Datasets

Mix multiple datasets with custom weights:

result = env.reset(
    dataset_name='composite',
    dataset_specs=[
        {
            "name": "leg_counting",
            "weight": 3,  # 3x more likely
            "config": {}
        },
        {
            "name": "reverse_sort",
            "weight": 1,
            "config": {"min_length": 3, "max_length": 5}
        }
    ],
    seed=42,
    size=20
)

Dataset Persistence

The dataset persists across resets until configuration changes:

# Create dataset
result = env.reset(dataset_name='leg_counting', seed=42, size=10)
question1 = result.observation.question

# Get next question from SAME dataset
result = env.reset()  # No params = reuse dataset
question2 = result.observation.question

# Create NEW dataset (different seed)
result = env.reset(dataset_name='leg_counting', seed=99, size=10)
question3 = result.observation.question  # From new dataset

Advanced Usage

Connecting to an Existing Server

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

from reasoning_gym_env import ReasoningGymEnv, ReasoningGymAction

# Connect to existing server
env = ReasoningGymEnv(base_url="http://localhost:8000")

# Use as normal
result = env.reset(
    dataset_name='leg_counting',
    dataset_config={"min_animals": 5, "max_animals": 15}
    seed=42,
    size=10
)
result = env.step(ReasoningGymAction(answer="4"))

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

Using the Context Manager

The client supports context manager usage for automatic connection management:

from reasoning_gym_env import ReasoningGymAction, ReasoningGymEnv

# Connect with context manager (auto-connects and closes)
with ReasoningGymEnv(base_url="http://localhost:8000") as env:
    result = env.reset(
        dataset_name='leg_counting',
        seed=42,
        size=5
    )
    print(f"Question: {result.observation.question}")

    # Multiple steps with low latency
    for i in range(5):
        result = env.step(ReasoningGymAction(answer="4"))
        print(f"Score: {result.observation.score}")
        if result.done:
            result = env.reset()  # Get next question

The client uses WebSocket connections for:

  • Lower latency: No HTTP connection overhead per request
  • Persistent session: Server maintains your environment state
  • Efficient for episodes: Better for many sequential steps

Concurrent WebSocket Sessions

The server is configured to support multiple concurrent WebSocket connections:

from reasoning_gym_env import ReasoningGymAction, ReasoningGymEnv
from concurrent.futures import ThreadPoolExecutor

def run_episode(client_id: int):
    with ReasoningGymEnv(base_url="http://localhost:8000") as env:
        result = env.reset(
            dataset_name='leg_counting',
            seed=42 + client_id,  # Different seed per client
            size=10
        )
        total_score = 0.0
        for i in range(10):
            result = env.step(ReasoningGymAction(answer="4"))
            total_score += result.observation.score
            if result.done:
                result = env.reset()  # Next question
        return client_id, total_score

# Run 4 episodes concurrently
with ThreadPoolExecutor(max_workers=4) as executor:
    results = list(executor.map(run_episode, range(4)))
    for client_id, score in results:
        print(f"Client {client_id}: Total score = {score}")

Development & Testing

Direct Environment Testing

Test the environment logic directly without starting the HTTP server:

# From the reasoning_gym_env directory
python3 server/reasoning_gym_environment.py

This verifies that:

  • Environment resets correctly
  • Step executes actions properly
  • Dataset creation and iteration works
  • Scoring is calculated correctly

Running Locally

Run the server locally for development:

# From the reasoning_gym_env directory
uvicorn server.app:app --reload

Then test with:

from reasoning_gym_env import ReasoningGymEnv, ReasoningGymAction

env = ReasoningGymEnv(base_url="http://localhost:8000")
result = env.reset(dataset_name='leg_counting', seed=42, size=5)
print(result.observation.question)

Project Structure

reasoning_gym_env/
β”œβ”€β”€ .dockerignore         # Docker build exclusions
β”œβ”€β”€ __init__.py           # Module exports
β”œβ”€β”€ README.md             # This file
β”œβ”€β”€ openenv.yaml          # OpenEnv manifest
β”œβ”€β”€ pyproject.toml        # Project metadata and dependencies
β”œβ”€β”€ client.py             # ReasoningGymEnv client
β”œβ”€β”€ models.py             # Action and Observation models
└── server/
    β”œβ”€β”€ __init__.py       # Server module exports
    β”œβ”€β”€ reasoning_gym_environment.py  # Core environment logic
    β”œβ”€β”€ app.py            # FastAPI application (HTTP + WebSocket endpoints)
    β”œβ”€β”€ requirements.txt  # Server dependencies
    └── Dockerfile        # Container image definition

Use Cases

The Reasoning Gym environment is ideal for:

  • LLM Evaluation: Benchmark reasoning capabilities across diverse tasks
  • Agent Training: Train RL agents on reasoning tasks with clear score signals
  • Curriculum Learning: Mix datasets with composite configurations for progressive difficulty
  • Research: Reproducible environments with seed control for scientific experiments
  • Educational: Learn about environment design and agent-environment interaction

Learn More

Update on GitHub