diff --git a/apps/backend/server.js b/apps/backend/server.js
index 4c5fb33..a891b19 100644
--- a/apps/backend/server.js
+++ b/apps/backend/server.js
@@ -955,6 +955,93 @@ const requireAdmin = (req, res, next) => {
   return res.status(401).json({ error: 'Authentication required' });
 };
 
+// Middleware to check if user has granted a specific consent category
+const requireConsent = (category) => {
+  return async (req, res, next) => {
+    try {
+      const userId = req.session?.userId;
+      const sessionId = req.sessionID;
+      let consent;
+      if (userId) {
+        consent = await userDbGet('SELECT granted FROM user_consents WHERE user_id = ? AND category = ?', [userId, category]);
+      } else if (sessionId) {
+        consent = await userDbGet('SELECT granted FROM user_consents WHERE session_id = ? AND category = ?', [sessionId, category]);
+      }
+      if (consent && consent.granted) return next();
+      return res.status(403).json({ error: `Consent required: ${category}` });
+    } catch (error) {
+      console.error('Consent check error:', error);
+      res.status(500).json({ error: 'Internal server error' });
+    }
+  };
+};
+
+// ========== CONSENT MANAGEMENT ==========
+app.get('/api/consents', async (req, res) => {
+  try {
+    const userId = req.session?.userId;
+    const sessionId = req.sessionID;
+    const categories = ['essential', 'analytics', 'preferences', 'health_data'];
+    const result = {};
+    categories.forEach(c => { result[c] = c === 'essential'; });
+    if (userId) {
+      const rows = await userDbAll('SELECT category, granted FROM user_consents WHERE user_id = ?', [userId]);
+      rows.forEach(r => { result[r.category] = r.granted; });
+    } else if (sessionId) {
+      const rows = await userDbAll('SELECT category, granted FROM user_consents WHERE session_id = ?', [sessionId]);
+      rows.forEach(r => { result[r.category] = r.granted; });
+    }
+    result.essential = true;
+    res.json(result);
+  } catch (error) {
+    console.error('Error fetching consents:', error);
+    res.status(500).json({ error: 'Internal server error' });
+  }
+});
+
+app.put('/api/consents', async (req, res) => {
+  try {
+    const userId = req.session?.userId;
+    const sessionId = req.sessionID;
+    const { categories } = req.body;
+    if (!categories || typeof categories !== 'object') {
+      return res.status(400).json({ error: 'categories object required' });
+    }
+    const allowedCategories = ['analytics', 'preferences', 'health_data'];
+    for (const cat of allowedCategories) {
+      if (cat in categories) {
+        const granted = Boolean(categories[cat]);
+        if (userId) {
+          await userDbRun(
+            `INSERT INTO user_consents (user_id, category, granted, updated_at) VALUES (?, ?, ?, CURRENT_TIMESTAMP) ON CONFLICT (user_id, category) DO UPDATE SET granted = ?, updated_at = CURRENT_TIMESTAMP`,
+            [userId, cat, granted, granted]
+          );
+        } else if (sessionId) {
+          await userDbRun(
+            `INSERT INTO user_consents (session_id, category, granted, updated_at) VALUES (?, ?, ?, CURRENT_TIMESTAMP) ON CONFLICT (session_id, category) DO UPDATE SET granted = ?, updated_at = CURRENT_TIMESTAMP`,
+            [sessionId, cat, granted, granted]
+          );
+        }
+      }
+    }
+    // Return updated consents
+    const result = { essential: true };
+    const cats = ['analytics', 'preferences', 'health_data'];
+    if (userId) {
+      const rows = await userDbAll('SELECT category, granted FROM user_consents WHERE user_id = ?', [userId]);
+      rows.forEach(r => { result[r.category] = r.granted; });
+    } else if (sessionId) {
+      const rows = await userDbAll('SELECT category, granted FROM user_consents WHERE session_id = ?', [sessionId]);
+      rows.forEach(r => { result[r.category] = r.granted; });
+    }
+    cats.forEach(c => { if (!(c in result)) result[c] = false; });
+    res.json(result);
+  } catch (error) {
+    console.error('Error saving consents:', error);
+    res.status(500).json({ error: 'Internal server error' });
+  }
+});
+
 // ========== RECENT SEARCHES (database-based) ==========
 
 const MAX_RECENT = 5;