Reinforcement Learning Sandbox Example
Demonstrates running a basic RL training loop (CartPole + DQN) inside an isolated OpenSandbox container. The example installs RL dependencies in the sandbox, trains a policy, saves a checkpoint, and returns a training summary.
Start OpenSandbox server [local]
Start the local OpenSandbox server:
shell
uv pip install opensandbox-server
opensandbox-server init-config ~/.sandbox.toml --example docker
opensandbox-serverRun the Example
shell
# Install OpenSandbox package
uv pip install opensandbox
# Run the example
uv run python examples/rl-training/main.pyThe script provisions a sandbox, installs RL dependencies, trains a DQN agent on CartPole, saves a checkpoint, and prints the JSON training summary.

Environment Variables
| Variable | Default | Description |
|---|---|---|
SANDBOX_DOMAIN | localhost:8080 | Sandbox service address |
SANDBOX_API_KEY | (optional) | API key if your server requires authentication |
SANDBOX_IMAGE | sandbox-registry.cn-zhangjiakou.cr.aliyuncs.com/opensandbox/code-interpreter:v1.1.0 | Docker image to use |
RL_TIMESTEPS | 5000 | Training timesteps to run |
TensorBoard
The training script logs to runs/. To visualize metrics, open a shell in the sandbox and run:
shell
tensorboard --logdir runs --host 0.0.0.0 --port 6006