Welcome to the GitHub for Hello Robot.

Here you will find open-source code for the Stretch 4 mobile manipulator as well as for the Stretch 3 and older versions of the robot.

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Stretch 4 Software Architecture

The Stretch 4 software ecosystem is organized into a multi-layered stack designed to transition seamlessly from low-level hardware control to high-level autonomous behaviors.

1. Hardware & Drivers (The Foundation): At the lowest level, stretch4_body and stretch_firmware handle direct communication with the robot's motors and sensors. This layer manages the 9-DOF movement, including the omnidirectional base, telescoping arm, and 3-axis wrist.
2. Perception & Modeling: To "see" the world, Stretch 4 utilizes specialized drivers like stretch4_pyhesai_wrapper for its dual 3D Lidars and stretch4_rgbd for enhanced depth sensing. The robot’s physical dimensions and kinematic constraints are defined in stretch4_urdf, which is essential for motion planning.
3. Simulation: Before deploying to physical hardware, the stretch4_mujoco stack allows developers to test algorithms in a high-fidelity physics environment.
4. Middleware & Application (The Interface): High-level control is primarily managed through stretch4_ros2, providing a standardized interface for navigation and manipulation. Interfaces like stretch4_web_teleop enable remote operation via a browser, while stretch4_grasping_demo showcases integrated AI capabilities using VLMs and visual servoing.

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Stretch 4 Public Repositories

The following table summarizes some of the key public repositories dedicated to the Stretch 4 platform.

Repository	Description	Primary Language
stretch4_body	Core Python SDK to interact with the Stretch 4 hardware and low-level joints.	Python
stretch4_ros2	The primary ROS 2 driver and package suite for autonomous operation.	Python
stretch4_urdf	Unified Robot Description Format (URDF) files for the Stretch 4 mobile manipulator.	Python/XML
stretch4_tray	Ubuntu system tray application for displaying battery level or launching Stretch tools	Python/Yaml
stretch4_install	Scripts to configure a fresh OS with Stretch 4's SDK	Bash
stretch4_mujoco	Official simulation stack built on the MuJoCo physics engine.	Python
stretch4_web_teleop	Accessible, web-based interface for remote teleoperation.	TypeScript
stretch4_kinematics	Kinematics and task-space control library for Stretch 4	Python
stretch4_grasping_demo	AI-powered demo utilizing VLMs and object tracking for visual servoing.	Python
stretch4_hybrid_marker_demo	LiDAR-reflective material + visible light ArUco marker demo.	Python
stretch4_rgbd	Methods to enhance and process RGB-D imagery from onboard cameras.	Python
stretch4_pyhesai_wrapper	Python wrapper for the Hesai JT128 3D hemispherical LiDARs.	C++ / Python
stretch4_human_perception	Specialized tools to enable the robot to perceive and track humans.	Python
stretch4_compliant_gripper	Modeling and control code for the standard Stretch 4 compliant gripper.	Python

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Note: Stretch 4 is currently intended for research, development, and laboratory use. It has not yet been certified for FCC Class A compliance.

Stretch 3 (and earlier) Public Repositories

The naming convention for Stretch 3 repositories typically follows a stretch_* or stretch_re* format, distinguishing them from the newer stretch4_* specific repos.

Significant repositories include

Repository	Description
stretch_ai	High-level intelligence suite for grasping, navigation, and LLM agents.
stretch_body	The core Python SDK for interacting with RE1, RE2, and Stretch 3 hardware.
stretch_ros2	Official support for ROS 2 Humble, including Nav2 and teleop demos.
stretch_firmware	Arduino-based firmware for the robot's motor controllers and IMU boards.
stretch_web_interface	A redesigned browser-based interface for remote "manipulation from anywhere".