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# NeMo Gym

> NeMo Gym is a library for evaluating and improving models and agents using environments.

NeMo Gym is a library for evaluating and improving models and agents using environments. NeMo Gym provides infrastructure to develop environments, scalably run evaluation and training, and a collection of popular benchmarks and training environments.

## When to Use NeMo Gym

* You need to **evaluate models or agents** in stateful environments (for example, code execution, tool calling, sandboxes).
* You want **reproducible evaluation** across teams using shared environments and verifiers.
* You need to use environments **at scale** — multiple repeats per task, or thousands of concurrent requests for training.
* You want to **seamlessly transition** between evaluation, agent optimization, and training.

If you are scoring model outputs with a stateless check and do not need scale or training, a script is probably sufficient.

## What NeMo Gym Provides

* Modular, extensible interfaces for agents, environments, tasks, and verifiers
* Environment hub of popular benchmarks and training environments
* Use your own agents or choose from built-in harnesses
* Scale to thousands of concurrent environments
* Train with the RL framework of your choice
* Battle-tested in production Nemotron training

![NeMo Gym Product Overview](https://fdr-prod-docs-files-public.s3.us-east-1.amazonaws.com/nvidia-gym.docs.buildwithfern.com/1f21af95c3aa75bf8425dab33fad469b4b724f6cdb434d53cdeaaf53e8c88ec9/assets/images/product_overview.png?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Content-Sha256=UNSIGNED-PAYLOAD&X-Amz-Credential=AKIA6KXJSKKNFOCF7G4B%2F20260818%2Fus-east-1%2Fs3%2Faws4_request&X-Amz-Date=20260818T182832Z&X-Amz-Expires=604800&X-Amz-Signature=fdab00b58934f4385cd25ba90b3f77260d4d3848f30ef8ca7ab30e867177ae52&X-Amz-SignedHeaders=host&x-amz-checksum-mode=ENABLED&x-id=GetObject)

## Integrations

NeMo Gym integrates with the broader agentic ecosystem:

* **Environment libraries**: Seamlessly combine environments and benchmarks from other libraries alongside NeMo Gym environments.
* **Training framework libraries**: Use environments for SFT and RL training.
* **Agent harnesses**: Popular agent harnesses for evaluation and training available out of the box.
* **Agent framework libraries**: Use your custom agent built with agent frameworks in NeMo Gym environments.
* **Sandboxes**: Isolate agent runtime execution.

## Next Steps

#### [Get Started](/get-started/installation)

Install NeMo Gym and run your first evaluation.

#### [Browse Environments](https://github.com/NVIDIA-NeMo/Gym#-available-environments)

Browse available environments for evaluation and training.

#### [Agents](/agent-server)

Explore available agent harnesses and learn how to integrate your own agent.

#### [Training](/tutorials/training-tutorials)

Improve your agent or model with RL or fine-tuning.

#### [Build Custom Environments](/environment-tutorials)

Create your own evaluation or training environments.