diff --git a/files/models.py b/files/models.py
index 9e9f853..ec8e24c 100644
--- a/files/models.py
+++ b/files/models.py
@@ -40,6 +40,26 @@ class SharedSpace(models.Model):
         default=0,
         help_text="Maximum file size in MB for uploads (0 = unlimited)"
     )
+
+    VISIBILITY_CHOICES = [
+        ('public', 'Public'),
+        ('public_read', 'Public Read'),
+        ('authenticated', 'Authenticated'),
+        ('members_only', 'Members Only'),
+    ]
+    visibility = models.CharField(
+        max_length=20,
+        choices=VISIBILITY_CHOICES,
+        default='public_read',
+        help_text="Who can access this space"
+    )
+    owner_did = models.CharField(
+        max_length=255,
+        blank=True,
+        default='',
+        help_text="EncryptID DID of the space owner"
+    )
+
     created_at = models.DateTimeField(auto_now_add=True)
     updated_at = models.DateTimeField(auto_now=True)
 
diff --git a/files/views.py b/files/views.py
index 5ed3ad0..04996f3 100644
--- a/files/views.py
+++ b/files/views.py
@@ -13,7 +13,8 @@ from rest_framework.decorators import action
 from rest_framework.response import Response
 from rest_framework.parsers import MultiPartParser, FormParser, JSONParser
 
-from .models import MediaFile, PublicShare, FileAccessLog
+from .models import MediaFile, PublicShare, FileAccessLog, SharedSpace
+from config.encryptid_auth import SpacePermission
 from .serializers import (
     MediaFileSerializer,
     MediaFileUploadSerializer,
@@ -30,7 +31,18 @@ class MediaFileViewSet(viewsets.ModelViewSet):
     queryset = MediaFile.objects.all()
     serializer_class = MediaFileSerializer
     parser_classes = [MultiPartParser, FormParser, JSONParser]
-    permission_classes = [permissions.IsAuthenticatedOrReadOnly]
+    permission_classes = [permissions.IsAuthenticatedOrReadOnly, SpacePermission]
+
+    def get_space_config(self, request):
+        """Provide space config for SpacePermission check."""
+        space_slug = request.query_params.get('space')
+        if not space_slug:
+            return None
+        try:
+            space = SharedSpace.objects.get(slug=space_slug, is_active=True)
+            return {'visibility': space.visibility, 'owner_did': space.owner_did}
+        except SharedSpace.DoesNotExist:
+            return None
 
     def get_serializer_class(self):
         if self.action == 'create':
diff --git a/portal/views_shared_space.py b/portal/views_shared_space.py
index c7bd7d7..deecd16 100644
--- a/portal/views_shared_space.py
+++ b/portal/views_shared_space.py
@@ -12,6 +12,7 @@ from django.views.decorators.csrf import csrf_exempt
 from django.utils.decorators import method_decorator
 
 from files.models import SharedSpace, MediaFile, PublicShare
+from config.encryptid_auth import check_space_access
 
 
 def get_topic_or_404(request):
@@ -54,11 +55,19 @@ class SharedSpaceHomeView(View):
 
 @method_decorator(csrf_exempt, name='dispatch')
 class SharedSpaceUploadAPIView(View):
-    """Handle file uploads via AJAX for topic."""
+    """Handle file uploads via AJAX for topic. Requires auth for non-public spaces."""
 
     def post(self, request):
         space = get_topic_or_404(request)
 
+        # Check space visibility — uploads are always writes
+        access = check_space_access(request, {
+            'visibility': space.visibility,
+            'owner_did': space.owner_did,
+        })
+        if not access['allowed']:
+            return JsonResponse({'error': access['reason']}, status=401)
+
         if not request.FILES.get('file'):
             return JsonResponse({'error': 'No file provided'}, status=400)
 
@@ -137,6 +146,7 @@ class DirectUploadAPIView(View):
     """Handle uploads via direct.rfiles.online (bypasses Cloudflare).
 
     Space slug is passed as a form field instead of from the subdomain.
+    Requires auth for non-public spaces.
     """
 
     def post(self, request):
@@ -146,6 +156,14 @@ class DirectUploadAPIView(View):
 
         space = get_object_or_404(SharedSpace, slug=space_slug, is_active=True)
 
+        # Check space visibility — uploads are always writes
+        access = check_space_access(request, {
+            'visibility': space.visibility,
+            'owner_did': space.owner_did,
+        })
+        if not access['allowed']:
+            return JsonResponse({'error': access['reason']}, status=401)
+
         if not request.FILES.get('file'):
             return JsonResponse({'error': 'No file provided'}, status=400)