Universal Cognitive Schema (UCS): An Open Standard for Portable AI Identity

The Universal Cognitive Schema (UCS) is an open, versioned, platform-agnostic data standard for representing a person's accumulated AI interaction profile across seven core dimensions: persona, expertise map, project graph, preference corpus, interaction patterns, trust boundaries, and temporal context. UCS addresses a structural gap in the AI landscape — no platform has incentive to build user-owned cognitive portability, so no neutral standard exists. This specification defines the schema, fidelity scoring model, zero-knowledge architecture principles, and selective disclosure design. Developed using a human-led agent-mesh methodology. GitHub: https://github.com/XwhyZ-WHYLD/universal-cognitive-schema