diff --git a/backend/routes/sessions.js b/backend/routes/sessions.js
index f362f99..ce28e9f 100644
--- a/backend/routes/sessions.js
+++ b/backend/routes/sessions.js
@@ -6,6 +6,7 @@ const { triggerWebhook } = require('../utils/webhooks');
 const { getWebSocketManager } = require('../utils/websocket-manager');
 const { startMonitor, stopMonitor, getMonitorSnapshot } = require('../utils/ecast-shard-client');
 const { computeNotesPreview } = require('../utils/notes-preview');
+const { optionalAuthenticateToken } = require('../middleware/optional-auth');
 
 const router = express.Router();
 
@@ -71,7 +72,7 @@ router.get('/active', (req, res) => {
 });
 
 // Get single session by ID
-router.get('/:id', (req, res) => {
+router.get('/:id', optionalAuthenticateToken, (req, res) => {
   try {
     const session = db.prepare(`
       SELECT 
@@ -87,7 +88,14 @@ router.get('/:id', (req, res) => {
       return res.status(404).json({ error: 'Session not found' });
     }
 
-    res.json(session);
+    const { has_notes, notes_preview } = computeNotesPreview(session.notes);
+
+    if (req.user) {
+      res.json({ ...session, has_notes, notes_preview });
+    } else {
+      const { notes, ...publicSession } = session;
+      res.json({ ...publicSession, has_notes, notes_preview });
+    }
   } catch (error) {
     res.status(500).json({ error: error.message });
   }
diff --git a/tests/api/regression-sessions.test.js b/tests/api/regression-sessions.test.js
index f888cdd..16f446d 100644
--- a/tests/api/regression-sessions.test.js
+++ b/tests/api/regression-sessions.test.js
@@ -7,7 +7,7 @@ describe('GET /api/sessions (regression)', () => {
     cleanDb();
   });
 
-  test('GET /api/sessions/:id returns session object', async () => {
+  test('GET /api/sessions/:id returns session object with preview for unauthenticated', async () => {
     const session = seedSession({ is_active: 1, notes: 'Test session' });
 
     const res = await request(app).get(`/api/sessions/${session.id}`);
@@ -17,9 +17,11 @@ describe('GET /api/sessions (regression)', () => {
       expect.objectContaining({
         id: session.id,
         is_active: 1,
-        notes: 'Test session',
+        has_notes: true,
+        notes_preview: 'Test session',
       })
     );
+    expect(res.body.notes).toBeUndefined();
     expect(res.body).toHaveProperty('games_played');
   });
 
diff --git a/tests/api/session-notes.test.js b/tests/api/session-notes.test.js
index 7c84eb5..4d0a4e8 100644
--- a/tests/api/session-notes.test.js
+++ b/tests/api/session-notes.test.js
@@ -104,3 +104,44 @@ describe('GET /api/sessions list', () => {
   });
 });
 
+describe('GET /api/sessions/:id notes visibility', () => {
+  beforeEach(() => {
+    cleanDb();
+  });
+
+  test('returns full notes when authenticated', async () => {
+    const session = seedSession({ notes: '**Full notes** here\n\nSecond paragraph' });
+
+    const res = await request(app)
+      .get(`/api/sessions/${session.id}`)
+      .set('Authorization', getAuthHeader());
+
+    expect(res.status).toBe(200);
+    expect(res.body.notes).toBe('**Full notes** here\n\nSecond paragraph');
+    expect(res.body.has_notes).toBe(true);
+    expect(res.body.notes_preview).toBe('Full notes here');
+  });
+
+  test('returns only preview when unauthenticated', async () => {
+    const session = seedSession({ notes: '**Full notes** here\n\nSecond paragraph' });
+
+    const res = await request(app)
+      .get(`/api/sessions/${session.id}`);
+
+    expect(res.status).toBe(200);
+    expect(res.body.notes).toBeUndefined();
+    expect(res.body.has_notes).toBe(true);
+    expect(res.body.notes_preview).toBe('Full notes here');
+  });
+
+  test('returns has_notes false when no notes', async () => {
+    const session = seedSession({ notes: null });
+
+    const res = await request(app)
+      .get(`/api/sessions/${session.id}`);
+
+    expect(res.status).toBe(200);
+    expect(res.body.has_notes).toBe(false);
+    expect(res.body.notes_preview).toBeNull();
+  });
+});