diff --git a/mobile/App.tsx b/mobile/App.tsx
index bcc143a..281df21 100644
--- a/mobile/App.tsx
+++ b/mobile/App.tsx
@@ -11,6 +11,7 @@ import { BatchReviewScreen } from './app/batch-review';
 import { PendingReviewScreen } from './app/pending-review';
 import { FileDetailScreen } from './app/file-detail';
 import { FileEditScreen } from './app/file-edit';
+import { FolderScreen } from './app/folder';
 
 const Stack = createNativeStackNavigator();
 const queryClient = new QueryClient();
@@ -37,6 +38,7 @@ export default function App() {
             options={{ title: 'Détails', headerTintColor: '#fff', headerStyle: { backgroundColor: '#000' } }}
           />
           <Stack.Screen name="FileEdit" component={FileEditScreen} options={{ title: 'Édition' }} />
+          <Stack.Screen name="Folder" component={FolderScreen} options={{ title: 'Dossier' }} />
         </Stack.Navigator>
       </NavigationContainer>
       <StatusBar style="auto" />
diff --git a/mobile/app/folder.tsx b/mobile/app/folder.tsx
new file mode 100644
index 0000000..fd0ea22
--- /dev/null
+++ b/mobile/app/folder.tsx
@@ -0,0 +1,288 @@
+import React, { useMemo, useState, useCallback, useEffect } from 'react';
+import { View, FlatList, StyleSheet, TouchableOpacity, Text, Dimensions, Alert } from 'react-native';
+import { useRoute, useNavigation, RouteProp } from '@react-navigation/native';
+import { NativeStackNavigationProp } from '@react-navigation/native-stack';
+import { MaterialIcons } from '@expo/vector-icons';
+import { useFiles, useFileImage, useDeleteFile } from '../hooks/useFiles';
+import { FileItem, isFolder } from '../types';
+import { FileThumbnail } from '../components/FileThumbnail';
+
+const NUM_COLUMNS = 3;
+const SCREEN_WIDTH = Dimensions.get('window').width;
+const ITEM_SIZE = (SCREEN_WIDTH - 16 * 2 - (NUM_COLUMNS - 1) * 6) / NUM_COLUMNS;
+
+type RootStackParamList = {
+  Folder: { folderId: string; folderName: string };
+  FileDetail: { fileIds: string[]; initialIndex: number };
+};
+
+type NavigationProp = NativeStackNavigationProp<RootStackParamList>;
+
+type FolderRouteProp = RouteProp<RootStackParamList, 'Folder'>;
+
+function FolderGridItem({ file, onPress, onLongPress, selected, onFolderPress }: {
+  file: FileItem;
+  onPress?: () => void;
+  onLongPress?: () => void;
+  selected?: boolean;
+  onFolderPress?: () => void;
+}) {
+  const { data, isLoading } = useFileImage(file.id);
+  const folder = isFolder(file);
+
+  return (
+    <TouchableOpacity
+      style={[styles.gridItem, selected && styles.gridItemSelected]}
+      onPress={folder ? onFolderPress : onPress}
+      onLongPress={onLongPress}
+      delayLongPress={400}
+      activeOpacity={0.7}
+    >
+      <FileThumbnail
+        uri={data?.data?.url}
+        mimeType={file.mimeType}
+        fileName={file.name}
+        size={ITEM_SIZE}
+        isLoading={isLoading}
+      />
+      {selected && (
+        <View style={styles.selectedOverlay}>
+          <View style={styles.checkCircle}>
+            <MaterialIcons name="check" size={18} color="#fff" />
+          </View>
+        </View>
+      )}
+      <Text style={styles.fileName} numberOfLines={1}>{file.name}</Text>
+    </TouchableOpacity>
+  );
+}
+
+export function FolderScreen() {
+  const route = useRoute<FolderRouteProp>();
+  const navigation = useNavigation<NavigationProp>();
+  const { folderId, folderName } = route.params;
+  const { data, isLoading, error } = useFiles();
+  const deleteFile = useDeleteFile();
+  const [selectedIds, setSelectedIds] = useState<Set<string>>(new Set());
+
+  const selectionMode = selectedIds.size > 0;
+
+  useEffect(() => {
+    navigation.setOptions({ title: folderName });
+  }, [navigation, folderName]);
+
+  const files = useMemo(() => {
+    const all = data?.data ?? [];
+    return all.filter((f) => f.parentFileId === folderId);
+  }, [data, folderId]);
+
+  const fileIdToIndex = useMemo(() => {
+    const map = new Map<string, number>();
+    files.forEach((f, i) => map.set(f.id, i));
+    return map;
+  }, [files]);
+
+  const toggleSelection = useCallback((id: string) => {
+    setSelectedIds((prev) => {
+      const next = new Set(prev);
+      if (next.has(id)) next.delete(id);
+      else next.add(id);
+      return next;
+    });
+  }, []);
+
+  const clearSelection = useCallback(() => {
+    setSelectedIds(new Set());
+  }, []);
+
+  const handleDelete = useCallback(() => {
+    const count = selectedIds.size;
+    if (count === 0) return;
+    Alert.alert(
+      'Supprimer',
+      `Supprimer ${count === 1 ? 'ce fichier' : `ces ${count} fichiers`} ?`,
+      [
+        { text: 'Annuler', style: 'cancel' },
+        {
+          text: 'Supprimer',
+          style: 'destructive',
+          onPress: async () => {
+            for (const id of selectedIds) {
+              await deleteFile.mutateAsync(id);
+            }
+            setSelectedIds(new Set());
+          },
+        },
+      ]
+    );
+  }, [selectedIds, deleteFile]);
+
+  const handleItemPress = useCallback((file: FileItem) => {
+    if (selectionMode) {
+      toggleSelection(file.id);
+    } else if (isFolder(file)) {
+      navigation.push('Folder', { folderId: file.id, folderName: file.name });
+    } else {
+      navigation.navigate('FileDetail', {
+        fileIds: files.map((f) => f.id),
+        initialIndex: fileIdToIndex.get(file.id) ?? 0,
+      });
+    }
+  }, [selectionMode, toggleSelection, navigation, files, fileIdToIndex]);
+
+  const handleItemLongPress = useCallback((file: FileItem) => {
+    if (!selectionMode) toggleSelection(file.id);
+  }, [selectionMode, toggleSelection]);
+
+  if (isLoading) {
+    return (
+      <View style={styles.center}>
+        <Text style={styles.infoText}>Chargement...</Text>
+      </View>
+    );
+  }
+
+  if (error) {
+    return (
+      <View style={styles.center}>
+        <Text style={styles.infoText}>Erreur de chargement</Text>
+      </View>
+    );
+  }
+
+  return (
+    <View style={styles.container}>
+      <FlatList
+        data={files}
+        keyExtractor={(item) => item.id}
+        contentContainerStyle={styles.list}
+        ListEmptyComponent={
+          <View style={styles.empty}>
+            <MaterialIcons name="folder-open" size={48} color="#ccc" />
+            <Text style={styles.emptyText}>Dossier vide</Text>
+          </View>
+        }
+        renderItem={({ item: file }) => (
+          <FolderGridItem
+            file={file}
+            selected={selectedIds.has(file.id)}
+            onPress={() => handleItemPress(file)}
+            onLongPress={() => handleItemLongPress(file)}
+            onFolderPress={() => navigation.push('Folder', { folderId: file.id, folderName: file.name })}
+          />
+        )}
+      />
+
+      {selectionMode && (
+        <View style={styles.selectionBar}>
+          <View style={styles.selectionHeader}>
+            <TouchableOpacity onPress={clearSelection} style={styles.cancelBtn}>
+              <MaterialIcons name="close" size={22} color="#333" />
+            </TouchableOpacity>
+            <Text style={styles.selectionCount}>
+              {selectedIds.size} sélectionnée{selectedIds.size > 1 ? 's' : ''}
+            </Text>
+          </View>
+          <TouchableOpacity style={styles.deleteBtn} onPress={handleDelete}>
+            <MaterialIcons name="delete" size={20} color="#F44336" />
+            <Text style={styles.deleteText}>Supprimer</Text>
+          </TouchableOpacity>
+        </View>
+      )}
+    </View>
+  );
+}
+
+const styles = StyleSheet.create({
+  container: {
+    flex: 1,
+    backgroundColor: '#f5f5f5',
+  },
+  center: {
+    flex: 1,
+    justifyContent: 'center',
+    alignItems: 'center',
+  },
+  infoText: {
+    fontSize: 16,
+    color: '#666',
+  },
+  list: {
+    padding: 15,
+  },
+  empty: {
+    paddingVertical: 60,
+    alignItems: 'center',
+    gap: 12,
+  },
+  emptyText: {
+    fontSize: 16,
+    color: '#999',
+  },
+  gridItem: {
+    width: ITEM_SIZE,
+  },
+  gridItemSelected: {
+    opacity: 0.85,
+  },
+  selectedOverlay: {
+    position: 'absolute',
+    top: 0,
+    left: 0,
+    right: 0,
+    bottom: 18,
+    justifyContent: 'flex-start',
+    alignItems: 'flex-end',
+    padding: 4,
+  },
+  checkCircle: {
+    width: 24,
+    height: 24,
+    borderRadius: 12,
+    backgroundColor: '#1976D2',
+    justifyContent: 'center',
+    alignItems: 'center',
+  },
+  fileName: {
+    fontSize: 11,
+    color: '#666',
+    marginTop: 4,
+    textAlign: 'center',
+  },
+  selectionBar: {
+    backgroundColor: '#fff',
+    borderTopWidth: 1,
+    borderTopColor: '#e0e0e0',
+    paddingHorizontal: 16,
+    paddingVertical: 12,
+  },
+  selectionHeader: {
+    flexDirection: 'row',
+    alignItems: 'center',
+    justifyContent: 'space-between',
+    marginBottom: 12,
+  },
+  cancelBtn: {
+    padding: 4,
+  },
+  selectionCount: {
+    fontSize: 16,
+    fontWeight: '600',
+    color: '#333',
+  },
+  deleteBtn: {
+    flexDirection: 'row',
+    alignItems: 'center',
+    justifyContent: 'center',
+    paddingVertical: 10,
+    borderRadius: 8,
+    borderWidth: 1.5,
+    borderColor: '#F44336',
+    gap: 6,
+  },
+  deleteText: {
+    fontSize: 15,
+    fontWeight: '600',
+    color: '#F44336',
+  },
+});
diff --git a/mobile/app/index.tsx b/mobile/app/index.tsx
index 52a8dfe..54221c3 100644
--- a/mobile/app/index.tsx
+++ b/mobile/app/index.tsx
@@ -5,7 +5,7 @@ import { useSafeAreaInsets } from 'react-native-safe-area-context';
 import { NativeStackNavigationProp } from '@react-navigation/native-stack';
 import { MaterialIcons } from '@expo/vector-icons';
 import { useFiles, useFileImage, useDeleteFile, useAddTags } from '../hooks/useFiles';
-import { FileItem } from '../types';
+import { FileItem, isFolder } from '../types';
 import { SearchBar, SearchFilters } from '../components/SearchBar';
 import { FileThumbnail } from '../components/FileThumbnail';
 
@@ -19,6 +19,7 @@ type RootStackParamList = {
   Scan: undefined;
   FileDetail: { fileIds: string[]; initialIndex: number };
   FileEdit: { fileIds: string[] };
+  Folder: { folderId: string; folderName: string };
 };
 
 type NavigationProp = NativeStackNavigationProp<RootStackParamList>;
@@ -111,14 +112,14 @@ function matchesQuery(file: FileItem, query: string, filters: SearchFilters): bo
   if (filters.name && file.name.toLowerCase().includes(q)) return true;
   if (filters.ocrText && file.ocrText?.toLowerCase().includes(q)) return true;
   if (filters.tags && file.tags?.some((t) => {
-    const tagName = typeof t === 'string' ? t : t.name;
+    const tagName = typeof t === 'string' ? t : t.tag_name;
     return tagName?.toLowerCase().includes(q);
   })) return true;
   if (!filters.name && !filters.ocrText && !filters.tags) {
     if (file.name.toLowerCase().includes(q)) return true;
     if (file.ocrText?.toLowerCase().includes(q)) return true;
     if (file.tags?.some((t) => {
-      const tagName = typeof t === 'string' ? t : t.name;
+      const tagName = typeof t === 'string' ? t : t.tag_name;
       return tagName?.toLowerCase().includes(q);
     })) return true;
   }
@@ -231,6 +232,8 @@ export function HomeScreen() {
   const handleItemPress = useCallback((file: FileItem) => {
     if (selectionMode) {
       toggleSelection(file.id);
+    } else if (isFolder(file)) {
+      navigation.navigate('Folder', { folderId: file.id, folderName: file.name });
     } else {
       navigation.navigate('FileDetail', {
         fileIds: filteredFiles.map((f) => f.id),
diff --git a/mobile/components/FileCard.tsx b/mobile/components/FileCard.tsx
index aad32f9..2ed5d11 100644
--- a/mobile/components/FileCard.tsx
+++ b/mobile/components/FileCard.tsx
@@ -43,7 +43,7 @@ export function FileCard({ file, onPress }: FileCardProps) {
 
       <View style={styles.tags}>
         {file.tags.map((tag) => (
-          <TagChip key={tag.id} name={tag.name} />
+          <TagChip key={tag.id} name={tag.tag_name} />
         ))}
       </View>
     </TouchableOpacity>
diff --git a/mobile/types/index.ts b/mobile/types/index.ts
index 450db5c..f3e1619 100644
--- a/mobile/types/index.ts
+++ b/mobile/types/index.ts
@@ -7,9 +7,14 @@ export interface FileItem {
   updatedAt: string;
   ocrText?: string;
   tags: Tag[];
+  parentFileId?: string;
   url?: string;
 }
 
+export function isFolder(file: FileItem): boolean {
+  return file.parentFileId != null;
+}
+
 export interface Tag {
   id: string;
   tag_name: string;