The VBDI Loop¶

The backward layer keeps memory faithful to what happened. The VBDI loop is its forward complement — it keeps delivery faithful to what was intended:

flowchart LR
  CS[Current State] --> V[Vision]
  V --> B[Blueprint]
  B --> D[Design]
  D --> I[Implementation]
  I --> F[Feedback]
  F -.-> CS

Only two primitives are new¶

Most of the loop already exists in the memory layer, so VBDI integrates by mapping, not rebuilding. Only Vision and Blueprint are genuinely new:

Primitive	Realized by
Current State	`continuity.md` (read at session start)
Vision (new)	`memory/vision.md` — the north star (`core`, invariant-verified)
Blueprint (new)	typed `(blueprint)` Open Threads — the Vision ↔ reality gaps
Design	Key Decisions + Architectural Invariants (optionally an ADR log)
Implementation	code / commits, traced in session logs
Feedback	the review ritual + decay + supersession

Why it stays lightweight¶

The trace is the determinism. Implementation → Design → Blueprint (serves: <gap>) → Vision (serves: <vision-id>), linked by stable ids. A missing or broken link is drift — and it is grep-detectable. The trace and the gates are deterministic; the content (the vision, the design ideas) is the open human–AI partnership. No scoring.
Human gates. Each altitude transition (confirming the Vision, opening/closing a gap) is an Open Thread the human checks off — the agent proposes, the human approves. Not a phase review.
Bootstrap, never fabricate. Enable and upgrade create a DRAFT Vision with only the safe current-state context inferred — the target is left for the human, gated by a (vision-bootstrap) thread. The Vision is the human's to set, like a user preference.
Process-neutral. The loop is the lightweight default; it neither requires nor forbids a heavier process. A target's owner may layer SDLC / scrum on top — that is their call — but ceremony and any scoring stay in the target's own space, never in memory/.

Memory is the deterministic substrate; the loop is the lightweight control layer. Together they yield predictable innovation with human partnership.

For the full design rationale, see the VBDI Lifecycle design note and the Agent Cognitive Framework.