Echo is a WARP optic runtime for witnessed causal history, Continuum-compatible suffixes, bounded observation, and holographic readings.

Observer Geometry I: Beyond Distance - Projection, Basis, Accumulation, and Observer Signatures.

Observer Geometry III manuscript source and Coq/Rocq finite reference model for path geometry, support obligations, witness debt, and provenance-aware audit.

Observer Geometry II: Distributed observer fields over shared causal history. Formalizes suffix transport, certified transport grids, and the geometric gap between state convergence and intent preservation.