diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index ed5b3e1..52378b6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -44,6 +44,9 @@ jobs:
       - name: Typecheck
         run: npm run lint
 
+      - name: Validate layer catalog
+        run: npm run validate:catalog
+
       - name: Test
         run: npm test
 
diff --git a/PROVENANCE.md b/PROVENANCE.md
new file mode 100644
index 0000000..e2a56a1
--- /dev/null
+++ b/PROVENANCE.md
@@ -0,0 +1,43 @@
+# Provenance & attribution
+
+This project is **MIT-licensed** (see per-file headers). This document records where
+non-original ideas, data and dependencies come from, and the licensing boundaries we
+respect — a discipline borrowed from [Marble's os-taxonomy](https://github.com/withmarbleapp/os-taxonomy),
+which cleanly separates database vs. authored-content licenses.
+
+## Original to this repo
+
+- The deterministic **103-layer engine** (`brainsnn-r3f-app/src/lib/layerRouter.js` and the
+  layer modules): the Cognitive Firewall, Affective Decoder, TRIBE-style projection, business
+  metrics, receipts, and **Layer 103 — the 39 Hz soliton field** (`solitonLayer.js`).
+- The **layer catalog** as a dependency-graphed, manifest-versioned dataset
+  (`src/lib/layerCatalog.js`, `data/layer-catalog.json`, `schema/layer-catalog.schema.json`).
+- The **stdio MCP server** (`mcp-server/`) and the **neural decoder gateway**
+  (`src/lib/neuralInputGateway.js`, `/api/neural/*`).
+
+## Dependencies (bundled)
+
+| Component | Source | License |
+| --- | --- | --- |
+| App runtime | React 19, Vite 6, Express 4, Tailwind | MIT |
+| WebGL 3D brain | `three`, `@react-three/fiber`, `@react-three/drei` (`src/features/brain3d/`) | MIT |
+| Agent bridge | `@modelcontextprotocol/sdk` (`mcp-server/`) | MIT |
+| Optional deep analysis | `@google/genai` (Gemini) — only when `GEMINI_API_KEY` is set | Apache-2.0 |
+
+## Inspirations & external boundaries (NOT bundled)
+
+- **Marble Skill Taxonomy — `withmarbleapp/os-taxonomy`** (database ODbL-1.0, content CC-BY-SA-4.0).
+  We borrowed the *approach* — a schema-validated graph with a prerequisite/dependency edge set,
+  a versioned manifest with a content hash, and a validator script. **No data was copied**; our
+  catalog and dependency edges are original to BrainSNN's own engine.
+- **Meta Brain2Qwerty** (research code **CC-BY-NC-4.0**). Our decoder gateway analyzes *decoded
+  text* from such a model but **does not bundle any Brain2Qwerty code, weights or data**. A real
+  decoder is reached only over the network via `NEURAL_DECODER_URL` (see
+  `docs/DECODER_TRANSCRIPT_GATEWAY.md`), keeping the NC boundary clean.
+- **Optional external services** — Stripe, Supabase, and a TRIBE projection service — are each
+  reached over the network behind an environment variable and are never required.
+
+## Data & measurement disclaimer
+
+BrainSNN outputs are AI-estimated content-response signals, **not** literal brain, biometric or
+EEG measurements. The engine is deterministic and stores no source recordings.
diff --git a/README.md b/README.md
index 612e4e6..8b06a44 100644
--- a/README.md
+++ b/README.md
@@ -225,6 +225,18 @@ This repo is a joint AI workspace coordinated through `.ai-memory/`. See `AGENTS
 - A new affect class in the decoder
 - A new soliton preset / sweep axis in `src/lib/solitonLayer.js`
 
+## The layer catalog as data
+
+The 103-layer catalog is published as a validated dataset — nodes plus a data-flow **dependency
+graph** and a versioned **manifest** (content-hashed) — inspired by
+[os-taxonomy](https://github.com/withmarbleapp/os-taxonomy):
+
+- `brainsnn-r3f-app/data/layer-catalog.json` — the dataset (regenerate with `npm run export:catalog`)
+- `brainsnn-r3f-app/schema/layer-catalog.schema.json` — its JSON Schema
+- `npm run validate:catalog` — structural + referential + acyclicity check (also gated in CI)
+- `GET /api/layers` now returns the `manifest` and `dependencies` alongside the layers
+
 ## License
 
-MIT — see per-file headers.
+MIT — see per-file headers. Sources, dependencies and external licensing boundaries are recorded
+in [PROVENANCE.md](PROVENANCE.md).
diff --git a/brainsnn-r3f-app/data/layer-catalog.json b/brainsnn-r3f-app/data/layer-catalog.json
new file mode 100644
index 0000000..8ba6412
--- /dev/null
+++ b/brainsnn-r3f-app/data/layer-catalog.json
@@ -0,0 +1,744 @@
+{
+  "manifest": {
+    "schemaVersion": "brainsnn.layer-catalog.v1",
+    "version": "1.0.0",
+    "totalLayers": 103,
+    "coreLayerIds": [
+      3,
+      4,
+      5,
+      29,
+      36,
+      39,
+      40,
+      46,
+      48,
+      63,
+      70,
+      101,
+      102,
+      103
+    ],
+    "dependencyEdges": 6,
+    "groups": {
+      "view": 18,
+      "firewall": 45,
+      "share": 12,
+      "data": 14,
+      "backend": 9,
+      "progression": 5
+    },
+    "contentHash": "smjcw2"
+  },
+  "groups": {
+    "view": {
+      "label": "3D & UX",
+      "color": "#00f5ff"
+    },
+    "firewall": {
+      "label": "Cognitive Firewall",
+      "color": "#a855f7"
+    },
+    "share": {
+      "label": "Share & Cards",
+      "color": "#f97316"
+    },
+    "data": {
+      "label": "Data & State",
+      "color": "#22c55e"
+    },
+    "backend": {
+      "label": "Backend & Agents",
+      "color": "#06b6d4"
+    },
+    "progression": {
+      "label": "Progression",
+      "color": "#eab308"
+    }
+  },
+  "layers": [
+    {
+      "id": 1,
+      "name": "3D Brain Viewer",
+      "group": "view",
+      "blurb": "3D & UX layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 2,
+      "name": "Neural Flow Grid",
+      "group": "view",
+      "blurb": "3D & UX layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 3,
+      "name": "TRIBE v2 Frames",
+      "group": "backend",
+      "blurb": "TRIBE v2 and scenario projections mapped to the 7-region BrainSNN model."
+    },
+    {
+      "id": 4,
+      "name": "Cognitive Firewall",
+      "group": "firewall",
+      "blurb": "Deterministic pressure scoring across urgency, outrage, certainty, fear and trust erosion."
+    },
+    {
+      "id": 5,
+      "name": "Gemma 4 Engine",
+      "group": "firewall",
+      "blurb": "Gemma endpoint support for deep multimodal analysis when configured server-side."
+    },
+    {
+      "id": 6,
+      "name": "Snapshots",
+      "group": "data",
+      "blurb": "Data & State layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 7,
+      "name": "Analytics Dashboard",
+      "group": "data",
+      "blurb": "Data & State layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 8,
+      "name": "Narrative Engine",
+      "group": "data",
+      "blurb": "Data & State layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 9,
+      "name": "Toast Notifications",
+      "group": "view",
+      "blurb": "3D & UX layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 10,
+      "name": "Keyboard Shortcuts",
+      "group": "view",
+      "blurb": "3D & UX layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 11,
+      "name": "Share & Embed",
+      "group": "share",
+      "blurb": "Share & Cards layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 12,
+      "name": "Onboarding Walkthrough",
+      "group": "view",
+      "blurb": "3D & UX layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 13,
+      "name": "Split Brain View",
+      "group": "view",
+      "blurb": "3D & UX layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 14,
+      "name": "AI Voice Narrator",
+      "group": "view",
+      "blurb": "3D & UX layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 15,
+      "name": "Plugin System",
+      "group": "data",
+      "blurb": "Data & State layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 16,
+      "name": "Live Sync",
+      "group": "share",
+      "blurb": "Share & Cards layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 17,
+      "name": "Heatmap Timeline",
+      "group": "data",
+      "blurb": "Data & State layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 18,
+      "name": "Knowledge Brain",
+      "group": "data",
+      "blurb": "Data & State layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 19,
+      "name": "MCP Bridge",
+      "group": "backend",
+      "blurb": "Backend & Agents layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 20,
+      "name": "Code-Aware Knowledge",
+      "group": "data",
+      "blurb": "Data & State layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 21,
+      "name": "Brain Steward",
+      "group": "backend",
+      "blurb": "Backend & Agents layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 22,
+      "name": "Conversation Brain",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 23,
+      "name": "Cognitive Immunity Score",
+      "group": "progression",
+      "blurb": "Progression layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 24,
+      "name": "Real Embeddings",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 25,
+      "name": "Red Team Simulator",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 26,
+      "name": "Dream Mode",
+      "group": "view",
+      "blurb": "3D & UX layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 27,
+      "name": "Adversarial Training",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 28,
+      "name": "Neuro-RAG",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 29,
+      "name": "Affective Decoder",
+      "group": "firewall",
+      "blurb": "12-affect trigger decoding across threat, reward, social and cognitive clusters."
+    },
+    {
+      "id": 30,
+      "name": "Neurochemistry Sandbox",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 31,
+      "name": "Brain Evolve",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 32,
+      "name": "Attack Evolve",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 33,
+      "name": "Multimodal RAG Router",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 34,
+      "name": "Vector-Graph Fusion",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 35,
+      "name": "Direct Content Insertion",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 36,
+      "name": "Autopsy Mode",
+      "group": "share",
+      "blurb": "Per-content autopsy and A/B battle rollups for variants and transcripts."
+    },
+    {
+      "id": 37,
+      "name": "Cognitive Fragments",
+      "group": "view",
+      "blurb": "3D & UX layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 38,
+      "name": "Daily Firewall Challenge",
+      "group": "progression",
+      "blurb": "Progression layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 39,
+      "name": "Propaganda Templates",
+      "group": "firewall",
+      "blurb": "Named manipulation and persuasion templates, surfaced as concrete evidence."
+    },
+    {
+      "id": 40,
+      "name": "Sentence Heatmap",
+      "group": "firewall",
+      "blurb": "Sentence-level heatmap annotation connected to recommendations."
+    },
+    {
+      "id": 41,
+      "name": "Refutation Library",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 42,
+      "name": "Counter-Draft",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 43,
+      "name": "Time-Series Autopsy",
+      "group": "share",
+      "blurb": "Share & Cards layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 44,
+      "name": "Inbox Mode",
+      "group": "share",
+      "blurb": "Share & Cards layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 45,
+      "name": "Semantic Templates",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 46,
+      "name": "Firewall Receipts",
+      "group": "share",
+      "blurb": "Deterministic scan receipt for export, share links and audit trails."
+    },
+    {
+      "id": 47,
+      "name": "Diff Mode",
+      "group": "share",
+      "blurb": "Share & Cards layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 48,
+      "name": "Ad Transparency",
+      "group": "firewall",
+      "blurb": "Ad transparency archetypes such as FOMO, proof gap and coercive scarcity."
+    },
+    {
+      "id": 49,
+      "name": "Scan Anywhere",
+      "group": "share",
+      "blurb": "Share & Cards layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 50,
+      "name": "Weekly Recap",
+      "group": "progression",
+      "blurb": "Progression layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 51,
+      "name": "Style Fingerprint",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 52,
+      "name": "Multi-lingual Firewall",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 53,
+      "name": "Echo Detector",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 54,
+      "name": "Public Scoring API",
+      "group": "backend",
+      "blurb": "Backend & Agents layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 55,
+      "name": "Custom Rules Editor",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 56,
+      "name": "Badge System",
+      "group": "progression",
+      "blurb": "Progression layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 57,
+      "name": "Data Portability",
+      "group": "data",
+      "blurb": "Data & State layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 58,
+      "name": "Image OCR Firewall",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 59,
+      "name": "Audio Firewall",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 60,
+      "name": "Firewall Macros",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 61,
+      "name": "Firewall Diagnostic",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 62,
+      "name": "Hypothesis Mode",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 63,
+      "name": "Context Memory",
+      "group": "data",
+      "blurb": "Entity and campaign memory for recurring context triggers."
+    },
+    {
+      "id": 64,
+      "name": "Debate Mode",
+      "group": "share",
+      "blurb": "Share & Cards layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 65,
+      "name": "Firewall Replay",
+      "group": "data",
+      "blurb": "Data & State layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 66,
+      "name": "Coverage Heatmap",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 67,
+      "name": "Calendar Heatmap",
+      "group": "data",
+      "blurb": "Data & State layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 68,
+      "name": "Tone Shifter",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 69,
+      "name": "Similarity Search",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 70,
+      "name": "Explanation Mode",
+      "group": "firewall",
+      "blurb": "Plain-English narration of what each engine layer contributed."
+    },
+    {
+      "id": 71,
+      "name": "Neural Oscillations",
+      "group": "view",
+      "blurb": "3D & UX layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 72,
+      "name": "Layer Explorer",
+      "group": "view",
+      "blurb": "3D & UX layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 73,
+      "name": "Text Adventure Training",
+      "group": "progression",
+      "blurb": "Progression layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 74,
+      "name": "Firewall Comparator",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 75,
+      "name": "Region Drill-Down",
+      "group": "view",
+      "blurb": "3D & UX layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 76,
+      "name": "Streaming Scoring API",
+      "group": "backend",
+      "blurb": "Backend & Agents layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 77,
+      "name": "Session Rooms",
+      "group": "share",
+      "blurb": "Share & Cards layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 78,
+      "name": "Vertical Card Variants",
+      "group": "share",
+      "blurb": "Share & Cards layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 79,
+      "name": "Compliment Detector",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 80,
+      "name": "Decoy / Sarcasm Detector",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 81,
+      "name": "Browser Extension Generator",
+      "group": "share",
+      "blurb": "Share & Cards layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 82,
+      "name": "MCP Tool Expansion",
+      "group": "backend",
+      "blurb": "Backend & Agents layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 83,
+      "name": "Rule Pack Library",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 84,
+      "name": "Scan Archive",
+      "group": "data",
+      "blurb": "Data & State layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 85,
+      "name": "Journalism Bulk Mode",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 86,
+      "name": "Privacy Budget",
+      "group": "data",
+      "blurb": "Data & State layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 87,
+      "name": "Genre Classifier",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 88,
+      "name": "Persona Simulator",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 89,
+      "name": "Refutation Composer",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 90,
+      "name": "Personal Dictionary",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 91,
+      "name": "PWA Install",
+      "group": "view",
+      "blurb": "3D & UX layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 92,
+      "name": "Command Palette",
+      "group": "view",
+      "blurb": "3D & UX layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 93,
+      "name": "Feedback Calibration",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 94,
+      "name": "Role Tour",
+      "group": "view",
+      "blurb": "3D & UX layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 95,
+      "name": "Image Bbox Annotation",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 96,
+      "name": "Cross-device Sync",
+      "group": "data",
+      "blurb": "Data & State layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 97,
+      "name": "Hotkey Map",
+      "group": "view",
+      "blurb": "3D & UX layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 98,
+      "name": "Theme + A11y",
+      "group": "view",
+      "blurb": "3D & UX layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 99,
+      "name": "Federated Community Firewall",
+      "group": "firewall",
+      "blurb": "Cognitive Firewall layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 100,
+      "name": "Milestone Dashboard",
+      "group": "view",
+      "blurb": "3D & UX layer preserved in the 103-layer engine stack."
+    },
+    {
+      "id": 101,
+      "name": "Gemini Deep Analysis",
+      "group": "backend",
+      "blurb": "Gemini/Gemma/OpenAI-style deep analysis and counter-draft guidance."
+    },
+    {
+      "id": 102,
+      "name": "Veea Lobster Trap",
+      "group": "backend",
+      "blurb": "Prompt injection, PII and secret preflight before model calls."
+    },
+    {
+      "id": 103,
+      "name": "39 Hz Soliton Field",
+      "group": "backend",
+      "blurb": "39 Hz microtubule soliton field: gamma-band synchrony and leapfrogging ionic solitons as a deterministic signal layer."
+    }
+  ],
+  "dependencies": [
+    {
+      "id": 29,
+      "dependsOn": [
+        4
+      ],
+      "reason": "Affect arousal is sharpened by the firewall's emotional-activation signal."
+    },
+    {
+      "id": 3,
+      "dependsOn": [
+        4,
+        29
+      ],
+      "reason": "The 7-region projection is driven by firewall pressure and affect valence/arousal."
+    },
+    {
+      "id": 48,
+      "dependsOn": [
+        4
+      ],
+      "reason": "Business metrics (manipulation risk, hook strength) derive from firewall signals."
+    },
+    {
+      "id": 103,
+      "dependsOn": [
+        4,
+        29
+      ],
+      "reason": "The soliton lattice is detuned by manipulation pressure and driven by affect arousal."
+    },
+    {
+      "id": 70,
+      "dependsOn": [
+        4,
+        29,
+        3
+      ],
+      "reason": "The narration summarizes what the firewall, affect and projection layers contributed."
+    },
+    {
+      "id": 46,
+      "dependsOn": [
+        4,
+        103
+      ],
+      "reason": "The receipt hashes the firewall signals and the soliton field for reproducibility."
+    }
+  ],
+  "coreLayerIds": [
+    3,
+    4,
+    5,
+    29,
+    36,
+    39,
+    40,
+    46,
+    48,
+    63,
+    70,
+    101,
+    102,
+    103
+  ]
+}
diff --git a/brainsnn-r3f-app/package.json b/brainsnn-r3f-app/package.json
index 22c0cad..26b70f7 100644
--- a/brainsnn-r3f-app/package.json
+++ b/brainsnn-r3f-app/package.json
@@ -12,7 +12,9 @@
     "lint": "tsc --noEmit",
     "test": "node scripts/test-runner.mjs",
     "test:run": "node scripts/test-runner.mjs",
-    "test:e2e": "playwright test"
+    "test:e2e": "playwright test",
+    "validate:catalog": "node scripts/validate-catalog.mjs",
+    "export:catalog": "node scripts/export-catalog.mjs"
   },
   "dependencies": {
     "@google/genai": "^2.4.0",
diff --git a/brainsnn-r3f-app/schema/layer-catalog.schema.json b/brainsnn-r3f-app/schema/layer-catalog.schema.json
new file mode 100644
index 0000000..dd22a96
--- /dev/null
+++ b/brainsnn-r3f-app/schema/layer-catalog.schema.json
@@ -0,0 +1,71 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://brainsnn.com/schema/layer-catalog.v1.json",
+  "title": "BrainSNN Layer Catalog",
+  "description": "The BrainSNN engine's layer catalog published as data: layers (nodes), a data-flow dependency graph (edges), and a versioned manifest. Generated by scripts/export-catalog.mjs.",
+  "type": "object",
+  "required": ["manifest", "groups", "layers", "dependencies", "coreLayerIds"],
+  "additionalProperties": false,
+  "properties": {
+    "manifest": {
+      "type": "object",
+      "required": ["schemaVersion", "version", "totalLayers", "coreLayerIds", "dependencyEdges", "groups", "contentHash"],
+      "additionalProperties": false,
+      "properties": {
+        "schemaVersion": { "type": "string", "const": "brainsnn.layer-catalog.v1" },
+        "version": { "type": "string" },
+        "totalLayers": { "type": "integer", "minimum": 1 },
+        "coreLayerIds": { "type": "array", "items": { "type": "integer", "minimum": 1 } },
+        "dependencyEdges": { "type": "integer", "minimum": 0 },
+        "groups": { "type": "object", "additionalProperties": { "type": "integer", "minimum": 0 } },
+        "contentHash": { "type": "string", "description": "Deterministic FNV-1a hash over layers + core ids + dependency edges." }
+      }
+    },
+    "groups": {
+      "type": "object",
+      "description": "Group id → { label, color }.",
+      "additionalProperties": {
+        "type": "object",
+        "required": ["label", "color"],
+        "properties": {
+          "label": { "type": "string" },
+          "color": { "type": "string" }
+        }
+      }
+    },
+    "layers": {
+      "type": "array",
+      "description": "The layers (graph nodes).",
+      "items": {
+        "type": "object",
+        "required": ["id", "name", "group", "blurb"],
+        "additionalProperties": false,
+        "properties": {
+          "id": { "type": "integer", "minimum": 1 },
+          "name": { "type": "string" },
+          "group": { "type": "string" },
+          "blurb": { "type": "string", "minLength": 1 }
+        }
+      }
+    },
+    "dependencies": {
+      "type": "array",
+      "description": "Data-flow edges: a layer depends on the layers whose output it consumes inside runLayerRouter. Must be acyclic.",
+      "items": {
+        "type": "object",
+        "required": ["id", "dependsOn", "reason"],
+        "additionalProperties": false,
+        "properties": {
+          "id": { "type": "integer", "minimum": 1 },
+          "dependsOn": { "type": "array", "items": { "type": "integer", "minimum": 1 } },
+          "reason": { "type": "string", "minLength": 1 }
+        }
+      }
+    },
+    "coreLayerIds": {
+      "type": "array",
+      "description": "The layers evaluated on every scan.",
+      "items": { "type": "integer", "minimum": 1 }
+    }
+  }
+}
diff --git a/brainsnn-r3f-app/scripts/export-catalog.mjs b/brainsnn-r3f-app/scripts/export-catalog.mjs
new file mode 100644
index 0000000..ccd600a
--- /dev/null
+++ b/brainsnn-r3f-app/scripts/export-catalog.mjs
@@ -0,0 +1,29 @@
+#!/usr/bin/env node
+// Publishes the layer catalog as pure data (os-taxonomy style): a single JSON
+// dataset consumable by agents/tools without importing the app's JS. Run after
+// changing the catalog: `npm run export:catalog`. A test keeps the committed
+// file in sync via the manifest content hash.
+import { writeFileSync } from 'node:fs';
+import { fileURLToPath } from 'node:url';
+import { dirname, join } from 'node:path';
+import {
+  LAYER_CATALOG,
+  LAYER_GROUPS,
+  LAYER_DEPENDENCIES,
+  CORE_LAYER_IDS,
+  getCatalogManifest,
+} from '../src/lib/layerCatalog.js';
+
+const here = dirname(fileURLToPath(import.meta.url));
+const outPath = join(here, '..', 'data', 'layer-catalog.json');
+
+const dataset = {
+  manifest: getCatalogManifest(),
+  groups: LAYER_GROUPS,
+  layers: LAYER_CATALOG,
+  dependencies: LAYER_DEPENDENCIES,
+  coreLayerIds: CORE_LAYER_IDS,
+};
+
+writeFileSync(outPath, `${JSON.stringify(dataset, null, 2)}\n`);
+console.log(`Wrote ${outPath} (hash ${dataset.manifest.contentHash})`);
diff --git a/brainsnn-r3f-app/scripts/validate-catalog.mjs b/brainsnn-r3f-app/scripts/validate-catalog.mjs
new file mode 100644
index 0000000..c3d699d
--- /dev/null
+++ b/brainsnn-r3f-app/scripts/validate-catalog.mjs
@@ -0,0 +1,18 @@
+#!/usr/bin/env node
+// Structural + referential integrity check for the layer catalog and its
+// dependency graph. Inspired by os-taxonomy's scripts/validate.mjs. Exits
+// non-zero on any error so CI can gate it.
+import { validateCatalog, getCatalogManifest } from '../src/lib/layerCatalog.js';
+
+const { ok, errors } = validateCatalog();
+const manifest = getCatalogManifest();
+
+if (!ok) {
+  console.error(`✗ Layer catalog invalid — ${errors.length} error(s):`);
+  for (const error of errors) console.error(`  - ${error}`);
+  process.exit(1);
+}
+
+console.log(
+  `✓ Layer catalog valid — ${manifest.totalLayers} layers, ${manifest.dependencyEdges} dependency edges, hash ${manifest.contentHash}`,
+);
diff --git a/brainsnn-r3f-app/server.ts b/brainsnn-r3f-app/server.ts
index 99ccc95..2b3ea75 100644
--- a/brainsnn-r3f-app/server.ts
+++ b/brainsnn-r3f-app/server.ts
@@ -10,7 +10,7 @@ import {
   getEngineStatusSnapshot,
   runLayerRouter
 } from "./src/lib/layerRouter.js";
-import { LAYER_CATALOG } from "./src/lib/layerCatalog.js";
+import { LAYER_CATALOG, LAYER_DEPENDENCIES, getCatalogManifest } from "./src/lib/layerCatalog.js";
 import { SOLITON_PRESETS, computeSolitonPreset, exploreSolitonField } from "./src/lib/solitonLayer.js";
 import { computeFirewall } from "./src/lib/firewallLayer.js";
 import { computeAffect } from "./src/lib/affectLayer.js";
@@ -173,8 +173,10 @@ app.get("/api/layers", (_req, res) => {
   const status = getEngineStatusSnapshot(process.env);
   res.json({
     totalLayers: LAYER_CATALOG.length,
+    manifest: (getCatalogManifest as any)(),
     coreLayers: status.coreLayers,
     layers: LAYER_CATALOG,
+    dependencies: LAYER_DEPENDENCIES,
   });
 });
 
diff --git a/brainsnn-r3f-app/src/lib/layerCatalog.js b/brainsnn-r3f-app/src/lib/layerCatalog.js
index 955d294..58aecb1 100644
--- a/brainsnn-r3f-app/src/lib/layerCatalog.js
+++ b/brainsnn-r3f-app/src/lib/layerCatalog.js
@@ -93,3 +93,116 @@ export function searchLayers(query = '', group = 'all') {
       || LAYER_GROUPS[layer.group]?.label.toLowerCase().includes(q);
   });
 }
+
+// ---------------------------------------------------------------------------
+// Layer dependency graph, manifest and validation
+// ---------------------------------------------------------------------------
+// Inspired by Marble's os-taxonomy (a schema-validated knowledge graph with a
+// prerequisite dependency graph, a versioned manifest and a validator). Here
+// the "prerequisites" are the real data-flow edges inside `runLayerRouter`:
+// which core layer consumes another layer's output.
+
+export const CATALOG_SCHEMA_VERSION = 'brainsnn.layer-catalog.v1';
+export const CATALOG_VERSION = '1.0.0';
+
+// { id, dependsOn: [ids], reason } — a DAG that mirrors runLayerRouter's flow.
+export const LAYER_DEPENDENCIES = [
+  { id: 29, dependsOn: [4], reason: 'Affect arousal is sharpened by the firewall\'s emotional-activation signal.' },
+  { id: 3, dependsOn: [4, 29], reason: 'The 7-region projection is driven by firewall pressure and affect valence/arousal.' },
+  { id: 48, dependsOn: [4], reason: 'Business metrics (manipulation risk, hook strength) derive from firewall signals.' },
+  { id: 103, dependsOn: [4, 29], reason: 'The soliton lattice is detuned by manipulation pressure and driven by affect arousal.' },
+  { id: 70, dependsOn: [4, 29, 3], reason: 'The narration summarizes what the firewall, affect and projection layers contributed.' },
+  { id: 46, dependsOn: [4, 103], reason: 'The receipt hashes the firewall signals and the soliton field for reproducibility.' },
+];
+
+export function dependenciesFor(id) {
+  return LAYER_DEPENDENCIES.find((edge) => edge.id === id)?.dependsOn ?? [];
+}
+
+function catalogHash() {
+  const payload = JSON.stringify({
+    layers: LAYER_CATALOG.map((layer) => [layer.id, layer.name, layer.group]),
+    core: CORE_LAYER_IDS,
+    deps: LAYER_DEPENDENCIES.map((edge) => [edge.id, edge.dependsOn]),
+  });
+  let hash = 2166136261;
+  for (let i = 0; i < payload.length; i += 1) {
+    hash ^= payload.charCodeAt(i);
+    hash = Math.imul(hash, 16777619);
+  }
+  return (hash >>> 0).toString(36);
+}
+
+// Deterministic manifest (no timestamps) so the content hash is stable and can
+// be cited by a scan receipt.
+export function getCatalogManifest() {
+  const groups = {};
+  for (const key of Object.keys(LAYER_GROUPS)) {
+    groups[key] = LAYER_CATALOG.filter((layer) => layer.group === key).length;
+  }
+  return {
+    schemaVersion: CATALOG_SCHEMA_VERSION,
+    version: CATALOG_VERSION,
+    totalLayers: LAYER_CATALOG.length,
+    coreLayerIds: [...CORE_LAYER_IDS],
+    dependencyEdges: LAYER_DEPENDENCIES.length,
+    groups,
+    contentHash: catalogHash(),
+  };
+}
+
+// Structural + referential integrity check. Returns { ok, errors }.
+export function validateCatalog() {
+  const errors = [];
+  const ids = LAYER_CATALOG.map((layer) => layer.id);
+  const idSet = new Set(ids);
+
+  if (idSet.size !== ids.length) errors.push('Duplicate layer ids.');
+  ids.forEach((id, index) => {
+    if (id !== index + 1) errors.push(`Layer ids must be contiguous from 1; got ${id} at position ${index + 1}.`);
+  });
+
+  LAYER_CATALOG.forEach((layer) => {
+    if (!LAYER_GROUPS[layer.group]) errors.push(`Layer ${layer.id} has unknown group "${layer.group}".`);
+    if (!layer.blurb || !layer.blurb.trim()) errors.push(`Layer ${layer.id} has an empty blurb.`);
+  });
+
+  new Set(CORE_LAYER_IDS).forEach((id) => {
+    if (!idSet.has(id)) errors.push(`CORE_LAYER_IDS references missing layer ${id}.`);
+  });
+  if (new Set(CORE_LAYER_IDS).size !== CORE_LAYER_IDS.length) errors.push('Duplicate ids in CORE_LAYER_IDS.');
+
+  const seenEdges = new Set();
+  LAYER_DEPENDENCIES.forEach((edge) => {
+    if (!idSet.has(edge.id)) errors.push(`Dependency references missing layer ${edge.id}.`);
+    if (seenEdges.has(edge.id)) errors.push(`Duplicate dependency entry for layer ${edge.id}.`);
+    seenEdges.add(edge.id);
+    (edge.dependsOn || []).forEach((dep) => {
+      if (!idSet.has(dep)) errors.push(`Layer ${edge.id} depends on missing layer ${dep}.`);
+      if (dep === edge.id) errors.push(`Layer ${edge.id} depends on itself.`);
+    });
+    if (!edge.reason || !edge.reason.trim()) errors.push(`Dependency ${edge.id} has no reason.`);
+  });
+
+  // Cycle detection (DFS over the dependency edges).
+  const adjacency = new Map(LAYER_DEPENDENCIES.map((edge) => [edge.id, edge.dependsOn || []]));
+  const state = new Map();
+  const visit = (node) => {
+    if (state.get(node) === 'done') return false;
+    if (state.get(node) === 'active') return true;
+    state.set(node, 'active');
+    for (const next of adjacency.get(node) || []) {
+      if (visit(next)) return true;
+    }
+    state.set(node, 'done');
+    return false;
+  };
+  for (const edge of LAYER_DEPENDENCIES) {
+    if (visit(edge.id)) {
+      errors.push(`Dependency cycle detected at layer ${edge.id}.`);
+      break;
+    }
+  }
+
+  return { ok: errors.length === 0, errors };
+}
diff --git a/brainsnn-r3f-app/src/lib/layerCatalog.test.js b/brainsnn-r3f-app/src/lib/layerCatalog.test.js
new file mode 100644
index 0000000..3def24a
--- /dev/null
+++ b/brainsnn-r3f-app/src/lib/layerCatalog.test.js
@@ -0,0 +1,46 @@
+import { readFileSync } from 'node:fs';
+import { describe, expect, it } from '../test/tinyVitest.js';
+import {
+  LAYER_CATALOG,
+  LAYER_DEPENDENCIES,
+  CORE_LAYER_IDS,
+  dependenciesFor,
+  getCatalogManifest,
+  validateCatalog,
+} from './layerCatalog.js';
+
+describe('layer catalog', () => {
+  it('passes structural + referential validation', () => {
+    const { ok, errors } = validateCatalog();
+    expect(errors).toHaveLength(0);
+    expect(ok).toBe(true);
+  });
+
+  it('produces a deterministic, self-consistent manifest', () => {
+    const manifest = getCatalogManifest();
+    expect(manifest.schemaVersion).toBe('brainsnn.layer-catalog.v1');
+    expect(manifest.totalLayers).toBe(LAYER_CATALOG.length);
+    expect(manifest.dependencyEdges).toBe(LAYER_DEPENDENCIES.length);
+    expect(getCatalogManifest().contentHash).toBe(manifest.contentHash);
+    const groupTotal = Object.values(manifest.groups).reduce((sum, count) => sum + count, 0);
+    expect(groupTotal).toBe(LAYER_CATALOG.length);
+  });
+
+  it('exposes an acyclic dependency graph that only references real core layers', () => {
+    const ids = new Set(LAYER_CATALOG.map((layer) => layer.id));
+    LAYER_DEPENDENCIES.forEach((edge) => {
+      expect(ids.has(edge.id)).toBe(true);
+      edge.dependsOn.forEach((dep) => expect(ids.has(dep)).toBe(true));
+    });
+    // The soliton layer (103) depends on firewall (4) and affect (29).
+    expect(dependenciesFor(103)).toContain(4);
+    expect(dependenciesFor(103)).toContain(29);
+  });
+
+  it('keeps the published data/layer-catalog.json in sync (run npm run export:catalog)', () => {
+    const dataset = JSON.parse(readFileSync(new URL('../../data/layer-catalog.json', import.meta.url), 'utf8'));
+    expect(dataset.manifest.contentHash).toBe(getCatalogManifest().contentHash);
+    expect(dataset.layers).toHaveLength(LAYER_CATALOG.length);
+    expect(dataset.coreLayerIds).toHaveLength(CORE_LAYER_IDS.length);
+  });
+});