This paper presents a generic ,modular and interactive architecture for embodied conversational agent called Greta. It is 3D agent able to communicate with users using verbal and non verbal channels like gaze, head and torso movements, facial expressions and gestures. Our architecture follows the SAIBA framework that defines modular structure, functionalities and communication protocols for ECA systems. In this paper, we present our architecture, performance tests as well as several interactive applications. MOTS-CL