Spar is an end-to-end learning platform that pairs students with a pedagogical thinking partner and educators with an AI teaching partner. For students, Spar guides work from raw ideas to finished essays while preserving the cognitive struggle that makes learning last. For teachers, Spar turns every assignment into a verifiable record of student thinking, surfacing insights across individual sessions, classrooms, and long-term cognitive development. By giving schools AI they can trust instead of finished work they cannot grade, Spar helps educators understand how students think and support learning at scale.