diff --git a/src/collection/collection.controller.ts b/src/collection/collection.controller.ts
index 8b966f9..cb7ee32 100644
--- a/src/collection/collection.controller.ts
+++ b/src/collection/collection.controller.ts
@@ -54,6 +54,15 @@ export class CollectionController {
     return this.collectionService.create(uid, createCollectionDto);
   }
 
+  @Post('add/:name')
+  addDocuments(
+    @GetUid() uid: string,
+    @Param('name') name: string,
+    @Body() docIds: string[],
+  ) {
+    return this.collectionService.addDocuments(uid, name, docIds);
+  }
+
   @Get('find/:name')
   findByName(
     @GetUid() uid: string,
diff --git a/src/collection/collection.service.ts b/src/collection/collection.service.ts
index efd1696..ed18c43 100644
--- a/src/collection/collection.service.ts
+++ b/src/collection/collection.service.ts
@@ -175,4 +175,36 @@ export class CollectionService {
       count: updatedCollection._count.documents,
     };
   }
+
+  async addDocuments(
+    uid: string,
+    name: string,
+    docIds: string[],
+  ): Promise<void> {
+    const user = await this.userService.findByUid(uid);
+    const collection = await this.prisma.collection.findUnique({
+      where: { name_userId: { userId: user.id, name } },
+    });
+
+    if (!collection) {
+      throw new BadRequestException('Collection does not exist');
+    }
+
+    const documents = await this.prisma.document.findMany({
+      select: { id: true },
+      where: {
+        userId: user.id,
+        docId: { in: docIds },
+      },
+    });
+
+    await this.prisma.collection.update({
+      where: { id: collection.id },
+      data: {
+        documents: {
+          connect: documents.map((doc) => ({ id: doc.id })),
+        },
+      },
+    });
+  }
 }