Architecture

System Overview

LuckyRobots is gRPC-only. The Python SDK connects directly to LuckyEngine over gRPC.

Components

LuckyEngine: Physics simulation backend (MuJoCo-based) exposing a gRPC server
Python client: LuckyEngineClient / LuckyRobots wrapper

Communication Architecture

┌───────────────┐          gRPC           ┌─────────────────┐
│ Python_Client │◄──────────────────────►│   LuckyEngine    │
│ (LuckyEngine  │     (default 50051)    │ (MuJoCo + gRPC)  │
│  Client)      │                        └─────────────────┘
└───────────────┘

gRPC Services

LuckyEngine exposes the following gRPC services (defined in hazel_rpc.proto):

SceneService: Scene inspection and entity manipulation
MujocoService: Joint state queries and control commands (SendControl, GetJointState)
AgentService: RL-style observation/action streaming, unified snapshots (GetObservation), and agent resets (ResetAgent)
TelemetryService: Telemetry data streaming
CameraService: Camera frame streaming
ViewportService: Viewport pixel streaming

Message System

LuckyRobots no longer includes a node / pubsub / service layer. All control and observation flows are direct gRPC calls to LuckyEngine.

Configuration

Default ports:

gRPC server (LuckyEngine): 127.0.0.1:50051

Environment variables:

LUCKYENGINE_PATH: Path to LuckyEngine executable
LUCKYENGINE_HOME: Directory containing LuckyEngine