Design Principles

Zero-loss (INV-1)

Every concept, technical detail, code block, and constraint in the input MUST appear in the output. The brief adds structure; it never subtracts meaning. Zero-loss is enforced by a persisted acu-index.json plus coverage computed by set-difference over the assembled draft --- never a hand [VERIFIED] stamp.

One question per turn

The HITL interview loop (N-INTERVIEW) asks the user exactly ONE question per turn. This keeps the interaction focused and ensures every answer is captured against a specific ACU.

Machine routes (INV-3)

The AI reasons at each node; the machine (goatcs-harness) routes. The two HITL pauses (N-INTERVIEW, N-REVIEW-GATE) are pure inline exit-11 (terminal-only UX). Deterministic impl nodes (capture, explorers, verify, coverage, emit, handoff) run as code on the drive path.