{
 "state": {
  "left_hand_world_joints": {
   "start": 0,
   "end": 63,
   "description": "Left 21 joints xyz, gravity-aligned metric WORLD frame, meters. 63=21x3, j00=wrist..j20=pinky-tip."
  },
  "left_finger_angles": {
   "start": 63,
   "end": 93,
   "description": "Left 15 finger joints x [flexion, abduction], signed radians, 30 values interleaved [j0_flex, j0_abd, j1_flex, ...]. Joint order is level-major, thumb->pinky within each level: [thumb_cmc, index_mcp, middle_mcp, ring_mcp, pinky_mcp, thumb_mcp, index_pip, middle_pip, ring_pip, pinky_pip, thumb_ip, index_dip, middle_dip, ring_dip, pinky_dip] (anatomical naming; per-dim names in info.json). Working range: flexion ~0-1.5, abduction ~+-0.4. Anatomical joint angles; retarget to robot-hand joints as needed."
  },
  "left_grip_closure": {
   "start": 93,
   "end": 94,
   "description": "Left grip-closure scalar in [0,1] = mean flexion of the 5 MCP + 5 PIP joints / 90deg, clipped. 0=open hand, 1=closed fist (reaches 1.0 in the data). Derived from 3D joints, not a fingertip/pinch distance."
  },
  "right_hand_world_joints": {
   "start": 94,
   "end": 157,
   "description": "Right 21 joints xyz, WORLD frame, meters."
  },
  "right_finger_angles": {
   "start": 157,
   "end": 187,
   "description": "Right 15 finger joints x [flexion, abduction], signed radians, 30 values interleaved [j0_flex, j0_abd, j1_flex, ...]. Joint order is level-major, thumb->pinky within each level: [thumb_cmc, index_mcp, middle_mcp, ring_mcp, pinky_mcp, thumb_mcp, index_pip, middle_pip, ring_pip, pinky_pip, thumb_ip, index_dip, middle_dip, ring_dip, pinky_dip] (anatomical naming; per-dim names in info.json). Working range: flexion ~0-1.5, abduction ~+-0.4. Anatomical joint angles; retarget to robot-hand joints as needed."
  },
  "right_grip_closure": {
   "start": 187,
   "end": 188,
   "description": "Right grip-closure scalar in [0,1] (mean MCP+PIP flexion / 90deg, clipped). 0=open hand, 1=closed fist."
  }
 },
 "video": {
  "main_stereo_left": {
   "original_key": "observation.images.main_stereo_left"
  },
  "main_stereo_right": {
   "original_key": "observation.images.main_stereo_right"
  },
  "aux_left": {
   "original_key": "observation.images.aux_left"
  },
  "aux_right": {
   "original_key": "observation.images.aux_right"
  }
 },
 "annotation": {
  "human.action.task_description": {
   "original_key": "task_index"
  }
 }
}