SignalBrain-OS is a GPU‑resident, deterministic autonomy kernel that fuses multi‑agent AI (including local LLM inference and topological signal encoding) into a pipeline that compiles probabilistic intent via the Apex17 policy compiler into verified, policy‑bounded action DSL and syscalls, executing locally with Merkle‑anchored tamper‑evident audit and full replayability; it guarantees identical inputs yield identical outputs, O(1) constant‑time recall on VRAM, and microsecond‑scale decisioning. Use it when you need low‑latency, auditable, safety‑constrained AI orchestration for mission‑critical domains—trading, robotics, defense, healthcare, or infrastructure—without cloud dependency and with governance enforced at compile time.