Fourier (Fourier Robotics) is a Shanghai-based robotics company that started in 2017 building rehabilitation exoskeletons and medical devices before moving into general-purpose humanoids. Its GRx line launched with the GR-1 in 2023, billed as one of the first mass-produced humanoids (1.65 m, 40 degrees of freedom), followed by the more capable GR-2 (1.75 m, 53 degrees of freedom, 12-DoF hands) and the GR-3 in 2025. Alongside the hardware it develops a software stack compatible with frameworks like NVIDIA Isaac Lab, ROS, and MuJoCo for training and control. The company targets research, healthcare/rehabilitation, and broader commercial and industrial applications.