Game SDK protocol v1

Direction	Message	Purpose
Game → Launcher	`client.hello`	authenticate with the session token
Game → Launcher	`game.ready`	report that the game is loaded
Launcher → Game	`session.start`	start the round
Launcher → Game	`target.hit`	deliver hit coordinates
Launcher → Game	`session.pause/resume/stop`	control the session
Game → Launcher	`score.update`	send a live result
Game → Launcher	`session.complete`	send the final result

Message envelope

{
  "msg": "target.hit",
  "seq": 18,
  "session_id": "session-123",
  "ts_monotonic_ms": 42114,
  "body": {
    "shot_id": "shot-0004",
    "x_mm": 1432,
    "y_mm": 817
  }
}

Control reasons

Message	Allowed values
session.pause	operator_requested, controller_unavailable, license_state_changed, focus_lost
session.stop	normal_end, operator_abort, host_shutdown, device_fault
device.state	ready, degraded, controller_lost, busy

Envelope schema: game-sdk-envelope.v1.schema.json.