The EU-funded JAST project is investigating the cognitive, neural, and communicative aspects of jointly-acting agents. This video shows a robot developed at the lab for Robotics and Embedded Systems at TUM as part of the project. The robot is able to build objects from wooden construction toys in cooperation with a human partner. It consists of two industrial manipulator arms mounted to resemble human arms and an animatronic head so that a human can interact with the system across a table. Various cameras are installed for the recognition of objects on the table, for gesture recognition, and for tracking the human. Force/torque sensors and grippers with position sensors on each arm complete the installation.