diff --git a/backend/src/lib/feature-flags.ts b/backend/src/lib/feature-flags.ts
index 047b706..3f65fe1 100644
--- a/backend/src/lib/feature-flags.ts
+++ b/backend/src/lib/feature-flags.ts
@@ -17,6 +17,13 @@ const registry = createFlagRegistry({
     'notelett_auto_embed_enabled': false,
     'notelett_duplicate_check_enabled': true,
     'notelett_suggest_links_enabled': true,
+    // Smart Actions feature flags (§6.3)
+    'notelett_smart_actions_enabled': false,
+    'notelett_auto_link_enabled': false,
+    'notelett_copilot_llm_enabled': false,
+    'notelett_voice_capture_enabled': false,
+    'notelett_scheduled_actions_enabled': false,
+    'notelett_webhooks_enabled': false,
   },
   enabled: config.FEATURE_FLAGS_ENABLED,
 });
diff --git a/backend/src/modules/note-prompts/routes.ts b/backend/src/modules/note-prompts/routes.ts
index 5945a78..1d04b38 100644
--- a/backend/src/modules/note-prompts/routes.ts
+++ b/backend/src/modules/note-prompts/routes.ts
@@ -6,6 +6,7 @@ import type { FastifyInstance } from 'fastify';
 import { z } from 'zod';
 import { getUserId, getRequestProductId } from '../../lib/request-context.js';
 import { BadRequestError, NotFoundError } from '@bytelyst/errors';
+import { isFeatureEnabled } from '../../lib/feature-flags.js';
 import { embedText, cosineSimilarity, stripHtmlForEmbedding } from '../../lib/embeddings.js';
 import { llm } from '../../lib/llm.js';
 import {
@@ -70,6 +71,7 @@ export async function notePromptRoutes(app: FastifyInstance): Promise<void> {
 
   // ── Run a prompt template against a note ────────────────────────
   app.post('/note-prompts/run', async (req) => {
+    if (!isFeatureEnabled('notelett_smart_actions_enabled')) throw new BadRequestError('Smart Actions are disabled');
     const userId = getUserId(req);
     const productId = getRequestProductId(req);
     const input = RunPromptSchema.parse(req.body);
diff --git a/backend/src/modules/note-prompts/scheduler.ts b/backend/src/modules/note-prompts/scheduler.ts
index aa1c004..6203331 100644
--- a/backend/src/modules/note-prompts/scheduler.ts
+++ b/backend/src/modules/note-prompts/scheduler.ts
@@ -12,6 +12,7 @@ import { getUserId, getRequestProductId } from '../../lib/request-context.js';
 import { BadRequestError, NotFoundError } from '@bytelyst/errors';
 import { getCollection } from '../../lib/datastore.js';
 import { PRODUCT_ID } from '../../lib/product-config.js';
+import { isFeatureEnabled } from '../../lib/feature-flags.js';
 import { llm } from '../../lib/llm.js';
 import * as noteRepo from '../notes/repository.js';
 import * as promptRepo from './repository.js';
@@ -241,6 +242,7 @@ export async function promptSchedulerRoutes(app: FastifyInstance): Promise<void>
   // ── Schedule CRUD ─────────────────────────────────────────────
 
   app.get('/prompt-schedules', async (req) => {
+    if (!isFeatureEnabled('notelett_scheduled_actions_enabled')) throw new BadRequestError('Scheduled actions are disabled');
     const userId = getUserId(req);
     const items = await scheduleCollection().findMany({
       filter: { productId: PRODUCT_ID, userId },
@@ -251,6 +253,7 @@ export async function promptSchedulerRoutes(app: FastifyInstance): Promise<void>
   });
 
   app.post('/prompt-schedules', async (req, reply) => {
+    if (!isFeatureEnabled('notelett_scheduled_actions_enabled')) throw new BadRequestError('Scheduled actions are disabled');
     const userId = getUserId(req);
     const input = CreateScheduleSchema.parse(req.body);
     const now = new Date().toISOString();
@@ -274,6 +277,7 @@ export async function promptSchedulerRoutes(app: FastifyInstance): Promise<void>
   });
 
   app.get('/prompt-schedules/:id', async (req) => {
+    if (!isFeatureEnabled('notelett_scheduled_actions_enabled')) throw new BadRequestError('Scheduled actions are disabled');
     const userId = getUserId(req);
     const { id } = req.params as { id: string };
     const doc = await scheduleCollection().findById(id, userId);
@@ -282,6 +286,7 @@ export async function promptSchedulerRoutes(app: FastifyInstance): Promise<void>
   });
 
   app.patch('/prompt-schedules/:id', async (req) => {
+    if (!isFeatureEnabled('notelett_scheduled_actions_enabled')) throw new BadRequestError('Scheduled actions are disabled');
     const userId = getUserId(req);
     const { id } = req.params as { id: string };
     const input = UpdateScheduleSchema.parse(req.body);
@@ -298,6 +303,7 @@ export async function promptSchedulerRoutes(app: FastifyInstance): Promise<void>
   });
 
   app.delete('/prompt-schedules/:id', async (req, reply) => {
+    if (!isFeatureEnabled('notelett_scheduled_actions_enabled')) throw new BadRequestError('Scheduled actions are disabled');
     const userId = getUserId(req);
     const { id } = req.params as { id: string };
     const existing = await scheduleCollection().findById(id, userId);
@@ -309,6 +315,7 @@ export async function promptSchedulerRoutes(app: FastifyInstance): Promise<void>
   // ── Webhook CRUD ──────────────────────────────────────────────
 
   app.get('/prompt-webhooks', async (req) => {
+    if (!isFeatureEnabled('notelett_webhooks_enabled')) throw new BadRequestError('Webhooks are disabled');
     const userId = getUserId(req);
     const items = await webhookCollection().findMany({
       filter: { productId: PRODUCT_ID, userId },
@@ -319,6 +326,7 @@ export async function promptSchedulerRoutes(app: FastifyInstance): Promise<void>
   });
 
   app.post('/prompt-webhooks', async (req, reply) => {
+    if (!isFeatureEnabled('notelett_webhooks_enabled')) throw new BadRequestError('Webhooks are disabled');
     const userId = getUserId(req);
     const input = CreateWebhookSchema.parse(req.body);
     const now = new Date().toISOString();
@@ -342,6 +350,7 @@ export async function promptSchedulerRoutes(app: FastifyInstance): Promise<void>
   });
 
   app.get('/prompt-webhooks/:id', async (req) => {
+    if (!isFeatureEnabled('notelett_webhooks_enabled')) throw new BadRequestError('Webhooks are disabled');
     const userId = getUserId(req);
     const { id } = req.params as { id: string };
     const doc = await webhookCollection().findById(id, userId);
@@ -350,6 +359,7 @@ export async function promptSchedulerRoutes(app: FastifyInstance): Promise<void>
   });
 
   app.patch('/prompt-webhooks/:id', async (req) => {
+    if (!isFeatureEnabled('notelett_webhooks_enabled')) throw new BadRequestError('Webhooks are disabled');
     const userId = getUserId(req);
     const { id } = req.params as { id: string };
     const input = UpdateWebhookSchema.parse(req.body);
@@ -361,6 +371,7 @@ export async function promptSchedulerRoutes(app: FastifyInstance): Promise<void>
   });
 
   app.delete('/prompt-webhooks/:id', async (req, reply) => {
+    if (!isFeatureEnabled('notelett_webhooks_enabled')) throw new BadRequestError('Webhooks are disabled');
     const userId = getUserId(req);
     const { id } = req.params as { id: string };
     const existing = await webhookCollection().findById(id, userId);
@@ -372,6 +383,7 @@ export async function promptSchedulerRoutes(app: FastifyInstance): Promise<void>
   // ── Trigger a webhook (F26) ───────────────────────────────────
 
   app.post('/prompt-webhooks/:id/trigger', async (req) => {
+    if (!isFeatureEnabled('notelett_webhooks_enabled')) throw new BadRequestError('Webhooks are disabled');
     const userId = getUserId(req);
     const { id } = req.params as { id: string };
     const input = TriggerWebhookSchema.parse(req.body);