Most AI is trained to agree with you. Spar is the opposite — an adversarial debate partner that pushes back, questions your sources, and finds the holes in your thinking. Pick from 6 archetypes (Cross-Examiner, Socratic, Journalist, Executive, Ideologue, Friendly Saboteur), argue any topic across 5 rounds, and get a coaching report on where your thinking held and where it broke. For debaters, writers, founders, and anyone who needs to defend their thinking. Built to make you sharper, not happier