The frustratometer calculates energetic frustration in protein structures based on the principle of minimal frustration (Wolynes et al.). It computes single residue, mutational, and configurational frustration indices using the AWSEM model (Associative memory, Water mediated, Structure and Energy Model) or DCA (Direct Coupling Analysis). Frustrated regions reveal competing evolutionary pressures and often correspond to functional sites such as catalytic domains, hinge regions, or binding interfaces.