diff --git a/packages/domain/src/auth/capabilities.ts b/packages/domain/src/auth/capabilities.ts
new file mode 100644
index 000000000..bb8d7b680
--- /dev/null
+++ b/packages/domain/src/auth/capabilities.ts
@@ -0,0 +1,88 @@
+/**
+ * Capabilities — minimal RBAC for Pilot 001-010
+ *
+ * Not pages — capabilities (what user CAN do).
+ * Roles are combinations of capabilities.
+ */
+
+export type Capability =
+  // Mission
+  | 'mission.create'
+  | 'mission.edit'
+  | 'mission.assign'
+  | 'mission.view'
+  // Artifact
+  | 'artifact.view'
+  | 'artifact.download'
+  | 'artifact.delete'
+  // Decision
+  | 'decision.review'
+  | 'decision.approve'
+  // Model (Developer Mode)
+  | 'model.train'
+  | 'model.deploy'
+  // Economy
+  | 'economy.view'
+  | 'economy.edit'
+  // Admin
+  | 'admin.users'
+  | 'admin.settings'
+  | 'admin.developerMode';
+
+export interface Role {
+  readonly id: string;
+  readonly name: string;
+  readonly capabilities: Capability[];
+}
+
+export const Roles: Record<string, Role> = {
+  superAdmin: {
+    id: 'super_admin',
+    name: 'Super Admin',
+    capabilities: [
+      'mission.create', 'mission.edit', 'mission.assign', 'mission.view',
+      'artifact.view', 'artifact.download', 'artifact.delete',
+      'decision.review', 'decision.approve',
+      'model.train', 'model.deploy',
+      'economy.view', 'economy.edit',
+      'admin.users', 'admin.settings', 'admin.developerMode',
+    ],
+  },
+  operator: {
+    id: 'operator',
+    name: 'Operator',
+    capabilities: [
+      'mission.create', 'mission.edit', 'mission.assign', 'mission.view',
+      'artifact.view', 'artifact.download',
+      'decision.review',
+      'model.train', 'model.deploy',
+      'economy.view',
+      'admin.developerMode',
+    ],
+  },
+  reviewer: {
+    id: 'reviewer',
+    name: 'Reviewer',
+    capabilities: [
+      'mission.view',
+      'artifact.view', 'artifact.download',
+      'decision.review', 'decision.approve',
+    ],
+  },
+  pilotUser: {
+    id: 'pilot_user',
+    name: 'Pilot User',
+    capabilities: [
+      'mission.create', 'mission.view',
+      'artifact.view',
+    ],
+  },
+};
+
+export function hasCapability(role: Role, capability: Capability): boolean {
+  return role.capabilities.includes(capability);
+}
+
+export function hasAnyCapability(role: Role, capabilities: Capability[]): boolean {
+  return capabilities.some(c => hasCapability(role, c));
+}
diff --git a/packages/domain/src/auth/feature-flags.ts b/packages/domain/src/auth/feature-flags.ts
new file mode 100644
index 000000000..981c771f8
--- /dev/null
+++ b/packages/domain/src/auth/feature-flags.ts
@@ -0,0 +1,50 @@
+/**
+ * Feature Flags — enable features without new releases
+ *
+ * Pilot 001-010: Control which modules are visible.
+ */
+
+export type FeatureFlag =
+  | 'ENABLE_REPLAY'
+  | 'ENABLE_DATASET_EXPLORER'
+  | 'ENABLE_MODEL_TRAINING'
+  | 'ENABLE_HOTSPOTS'
+  | 'ENABLE_ECONOMIC_ENGINE'
+  | 'ENABLE_DEVELOPER_MODE';
+
+export interface FeatureFlags {
+  readonly flags: Record<FeatureFlag, boolean>;
+}
+
+export const DefaultFeatureFlags: FeatureFlags = {
+  flags: {
+    ENABLE_REPLAY: false,
+    ENABLE_DATASET_EXPLORER: true,
+    ENABLE_MODEL_TRAINING: false,
+    ENABLE_HOTSPOTS: false,
+    ENABLE_ECONOMIC_ENGINE: false,
+    ENABLE_DEVELOPER_MODE: false,
+  },
+};
+
+export function isEnabled(flags: FeatureFlags, flag: FeatureFlag): boolean {
+  return flags.flags[flag] ?? false;
+}
+
+export function enable(flags: FeatureFlags, flag: FeatureFlag): FeatureFlags {
+  return {
+    flags: {
+      ...flags.flags,
+      [flag]: true,
+    },
+  };
+}
+
+export function disable(flags: FeatureFlags, flag: FeatureFlag): FeatureFlags {
+  return {
+    flags: {
+      ...flags.flags,
+      [flag]: false,
+    },
+  };
+}
diff --git a/packages/domain/src/index.ts b/packages/domain/src/index.ts
index 399b3975c..8f80940d3 100644
--- a/packages/domain/src/index.ts
+++ b/packages/domain/src/index.ts
@@ -88,6 +88,24 @@ export {
 } from './mission/knowledge-gap';
 
 export * from './common/enums';
+
+// Auth
+export {
+  Capability,
+  Role,
+  Roles,
+  hasCapability,
+  hasAnyCapability,
+} from './auth/capabilities';
+
+export {
+  FeatureFlag,
+  FeatureFlags,
+  DefaultFeatureFlags,
+  isEnabled,
+  enable,
+  disable,
+} from './auth/feature-flags';
 export * from './common/errors';
 
 // Artifacts
diff --git a/packages/ui/src/App.tsx b/packages/ui/src/App.tsx
index e878c3a92..fc26edc85 100644
--- a/packages/ui/src/App.tsx
+++ b/packages/ui/src/App.tsx
@@ -1,4 +1,5 @@
 import { Routes, Route, Link } from 'react-router-dom';
+import { useState } from 'react';
 import DatasetExplorer from './pages/DatasetExplorer';
 import ArtifactViewer from './pages/ArtifactViewer';
 import MissionUpload from './pages/MissionUpload';
@@ -8,10 +9,26 @@ import PilotChecklist from './pages/PilotChecklist';
 import ReadinessDashboard from './pages/ReadinessDashboard';
 
 function App() {
+  const [developerMode, setDeveloperMode] = useState(false);
+
   return (
     <div style={{ fontFamily: 'system-ui, sans-serif', maxWidth: 1200, margin: '0 auto', padding: 20 }}>
       <header style={{ borderBottom: '2px solid #333', paddingBottom: 20, marginBottom: 20 }}>
-        <h1>LandveX Intelligence Lab</h1>
+        <div style={{ display: 'flex', justifyContent: 'space-between', alignItems: 'center' }}>
+          <h1>LandveX {developerMode ? '(Developer Mode)' : ''}</h1>
+          <button
+            onClick={() => setDeveloperMode(!developerMode)}
+            style={{
+              padding: '8px 16px',
+              background: developerMode ? '#ffd700' : '#f0f0f0',
+              border: '1px solid #ccc',
+              borderRadius: 4,
+              cursor: 'pointer',
+            }}
+          >
+            {developerMode ? '🔓 Developer' : '🔒 Normal'}
+          </button>
+        </div>
         <nav style={{ display: 'flex', gap: 20, marginTop: 10 }}>
           <Link to="/">Dataset Explorer</Link>
           <Link to="/upload">Mission Upload</Link>
@@ -19,6 +36,13 @@ function App() {
           <Link to="/health">Health</Link>
           <Link to="/pilot">Pilot 001</Link>
           <Link to="/readiness">Readiness</Link>
+          {developerMode && (
+            <>
+              <Link to="/datasets">Datasets</Link>
+              <Link to="/models">Models</Link>
+              <Link to="/training">Training</Link>
+            </>
+          )}
         </nav>
       </header>