generated: '2026-07-20'
method: derived
source: >-
  https://raw.githubusercontent.com/ultraleap/leapc-python-bindings/main/leapc-python-api/src/leap/
  (datatypes.py, events.py, enums.py) — first-party Gemini LeapC Python bindings
notes: >-
  LeapC has no REST resources or $ref graph; its "data model" is the set of C
  structs delivered on the message pump. This ERD is derived from the first-party
  Python bindings that wrap the LeapC structs. A LEAP_CONNECTION is polled with
  LeapPollConnection(), which yields LEAP_CONNECTION_MESSAGE events; the marquee
  payload is LEAP_TRACKING_EVENT, which carries an array of LEAP_HAND, each hand
  carrying a palm and five digits, each digit carrying four bones.
root: LEAP_CONNECTION
entities:
- name: Connection
  cstruct: LEAP_CONNECTION
  description: A client session to the local Ultraleap Hand Tracking Service; opened, then driven by a poll loop.
- name: Event
  cstruct: LEAP_CONNECTION_MESSAGE
  description: A polled message with an EventType discriminator (tracking, device, policy, config, log, image, connection).
- name: TrackingEvent
  cstruct: LEAP_TRACKING_EVENT
  description: A tracking frame with a frame id, timestamp, framerate and an array of hands.
  fields: [info, timestamp, tracking_frame_id, framerate, hands]
- name: Hand
  cstruct: LEAP_HAND
  description: A single tracked hand with type (left/right), a palm and five digits.
  fields: [id, type, palm, digits, arm]
- name: Palm
  cstruct: LEAP_PALM
  fields: [position, stabilized_position, velocity, normal, width, direction, orientation]
- name: Digit
  cstruct: LEAP_DIGIT
  description: A finger, composed of four bones plus an is_extended flag.
  fields: [finger_id, bones, is_extended]
- name: Bone
  cstruct: LEAP_BONE
  fields: [prev_joint, next_joint, width, rotation]
- name: Device
  cstruct: LEAP_DEVICE
  description: A physical tracking camera; referenced by device events by device_id.
- name: Vector
  cstruct: LEAP_VECTOR
  fields: [x, y, z]
- name: Quaternion
  cstruct: LEAP_QUATERNION
  fields: [x, y, z, w]
relationships:
- from: Connection
  to: Event
  kind: has_many
  via: LeapPollConnection message pump
- from: TrackingEvent
  to: Hand
  kind: has_many
  via: hands (nHands / pHands)
- from: Hand
  to: Palm
  kind: has_one
  via: palm
- from: Hand
  to: Digit
  kind: has_many
  via: digits (5 fingers)
- from: Digit
  to: Bone
  kind: has_many
  via: bones (4 per digit)
- from: Palm
  to: Vector
  kind: has_many
  via: position / velocity / normal / direction
- from: Bone
  to: Quaternion
  kind: has_one
  via: rotation
- from: Event
  to: Device
  kind: belongs_to
  via: metadata.device_id
event_types:
- ConnectionEvent
- ConnectionLostEvent
- DeviceEvent
- DeviceFailureEvent
- DeviceStatusChangeEvent
- DeviceLostEvent
- PolicyEvent
- TrackingEvent
- ImageCompleteEvent
- ImageRequestErrorEvent
- LogEvent
- ConfigResponseEvent
- ConfigChangeEvent