# Xtrainer2 policy interface

The optional policy server is in `deployment/model_server`. Configure it with a
model checkpoint and the matching training configuration and dataset statistics.
The client is a separate component and is not distributed in this artifact.

The client sends camera observations, proprioception, and a task instruction.
For the supplied bimanual configurations, its proprioception and actions use
16 absolute end-effector values: position, quaternion, and gripper for each arm.
The model internally uses 20 values after quaternion to rotation-6D conversion.
The client quaternion format is `xyzw`; dataset conversion and normalization
must follow the selected configuration. The pick-bottle configuration composes
relative actions on the server before returning absolute client actions.

Check the model architecture, action dimension, normalization statistics,
camera names, and action chunk size against the checkpoint before deployment.
Only use a client whose message schema matches the server's documented policy
interface. Robot hardware and control software are outside this review package.