diff --git a/src/main/kotlin/echo/org/Application.kt b/src/main/kotlin/echo/org/Application.kt
index 51fa2b8..cc7b4a2 100644
--- a/src/main/kotlin/echo/org/Application.kt
+++ b/src/main/kotlin/echo/org/Application.kt
@@ -1,15 +1,11 @@
 package echo.org
 
-import echo.org.application.route.DocumentModule
+
 import echo.org.instructure.AliyunOss
 import echo.org.instructure.DatabaseSingleton
-import echo.org.plugins.configureRouting
-import echo.org.plugins.configureSecurity
-import echo.org.plugins.configureSerialization
-import echo.org.plugins.configureTemplating
+import echo.org.plugins.*
 import io.ktor.server.application.*
-import org.koin.ktor.ext.inject
-import org.koin.ktor.plugin.Koin
+
 
 fun main(args: Array<String>) {
     io.ktor.server.netty.EngineMain.main(args)
@@ -17,16 +13,13 @@ fun main(args: Array<String>) {
 }
 
 fun Application.module() {
-    // Initialize Koin
-    install(Koin) {
-        modules(DocumentModule)
-    }
     AliyunOss.init()
     configureSecurity()
     configureSerialization()
     configureRouting()
     configureTemplating()
     initDatabase()
+    configureKoin()
 }
 
 fun Application.initDatabase() {
diff --git a/src/main/kotlin/echo/org/application/route/DocumentRoute.kt b/src/main/kotlin/echo/org/application/route/DocumentRoute.kt
index 42c3c3b..4d4fa04 100644
--- a/src/main/kotlin/echo/org/application/route/DocumentRoute.kt
+++ b/src/main/kotlin/echo/org/application/route/DocumentRoute.kt
@@ -17,16 +17,10 @@ import java.net.URLEncoder
 import java.nio.charset.StandardCharsets
 import java.time.LocalDateTime
 
-val DocumentModule = module {
-    single<DocumentRepository> { DocumentRepositoryImpl() }
-    single<FileOSS> { AliyunOssFileServiceImpl() }
-}
 
 fun Route.handleDocuments() {
-
     val documentRepository by inject<DocumentRepository>()
     val fileOSS by inject<FileOSS>()
-
     route("/documents") {
         get("") {
             val res = documentRepository.pageQuery(DocumentQueryParam())
diff --git a/src/main/kotlin/echo/org/domain/Folder.kt b/src/main/kotlin/echo/org/domain/Folder.kt
index 16f1ec5..1f6b30a 100644
--- a/src/main/kotlin/echo/org/domain/Folder.kt
+++ b/src/main/kotlin/echo/org/domain/Folder.kt
@@ -50,10 +50,10 @@ interface FolderRepository {
     suspend fun getDocumentsInFolder(folderId: Long): List<Document>
 
     // Add a document to a folder
-    suspend fun addDocumentToFolder(folderId: Long, documentId: Long)
+    suspend fun addDocumentToFolder(folderId: Long, documentIdList: List<Long>)
 
     // Remove a document from a folder
-    suspend fun removeDocumentFromFolder(folderId: Long, documentId: Long)
+    suspend fun removeDocumentFromFolder(folderId: Long, documentIdList: List<Long>)
 
     // Search folders by name or tags
     suspend fun searchFolders(query: String): List<Folder>
diff --git a/src/main/kotlin/echo/org/instructure/FolderExposed.kt b/src/main/kotlin/echo/org/instructure/FolderExposed.kt
index a2f63c2..7a3d14d 100644
--- a/src/main/kotlin/echo/org/instructure/FolderExposed.kt
+++ b/src/main/kotlin/echo/org/instructure/FolderExposed.kt
@@ -10,6 +10,7 @@ import echo.org.instructure.Folders.id
 import echo.org.instructure.Folders.parentFolderId
 import org.jetbrains.exposed.sql.*
 import org.jetbrains.exposed.sql.SqlExpressionBuilder.eq
+import org.jetbrains.exposed.sql.SqlExpressionBuilder.inList
 import org.jetbrains.exposed.sql.javatime.CurrentDateTime
 import org.jetbrains.exposed.sql.javatime.datetime
 import java.time.LocalDateTime
@@ -115,12 +116,18 @@ class FolderRepositoryImpl : FolderRepository {
         }
     }
 
-    override suspend fun addDocumentToFolder(folderId: Long, documentId: Long) = dbQuery {
-        TODO("Not yet implemented")
+    override suspend fun addDocumentToFolder(folderId: Long, documentIdList: List<Long>): Unit = dbQuery {
+        FolderDocuments.batchInsert(documentIdList) {
+            this[FolderDocuments.folderId] = folderId
+            this[documentId] = documentId
+        }
     }
 
-    override suspend fun removeDocumentFromFolder(folderId: Long, documentId: Long) = dbQuery {
-        TODO("Not yet implemented")
+    override suspend fun removeDocumentFromFolder(folderId: Long, documentIdList: List<Long>): Unit = dbQuery {
+        FolderDocuments.deleteWhere {
+            (FolderDocuments.folderId eq folderId) and
+                    (documentId inList documentIdList)
+        }
     }
 
     override suspend fun searchFolders(query: String): List<Folder> = dbQuery {
@@ -128,5 +135,4 @@ class FolderRepositoryImpl : FolderRepository {
             (Folders.name like "%$query%") or (Folders.tags like "%$query%")
         }.map { Folders.toFolder(it) }
     }
-
 }
\ No newline at end of file
diff --git a/src/main/kotlin/echo/org/plugins/Koin.kt b/src/main/kotlin/echo/org/plugins/Koin.kt
new file mode 100644
index 0000000..9fd1876
--- /dev/null
+++ b/src/main/kotlin/echo/org/plugins/Koin.kt
@@ -0,0 +1,27 @@
+package echo.org.plugins
+
+import echo.org.application.route.handleDocuments
+import echo.org.domain.DocumentRepository
+import echo.org.domain.FileOSS
+import echo.org.instructure.AliyunOssFileServiceImpl
+import echo.org.instructure.DocumentRepositoryImpl
+import io.ktor.server.application.*
+import io.ktor.server.http.content.*
+import io.ktor.server.routing.*
+import org.koin.dsl.module
+import org.koin.ktor.plugin.Koin
+
+
+val DocumentModule = module {
+    single<DocumentRepository> { DocumentRepositoryImpl() }
+    single<FileOSS> { AliyunOssFileServiceImpl() }
+
+}
+
+
+fun Application.configureKoin() {
+    // Initialize Koin
+    install(Koin) {
+        modules(DocumentModule)
+    }
+}
\ No newline at end of file
diff --git a/src/test/kotlin/echo/org/ApplicationTest.kt b/src/test/kotlin/echo/org/ApplicationTest.kt
index 8c50952..527aefd 100644
--- a/src/test/kotlin/echo/org/ApplicationTest.kt
+++ b/src/test/kotlin/echo/org/ApplicationTest.kt
@@ -1,17 +1,12 @@
 package echo.org
 
-import echo.org.application.route.DocumentModule
-import echo.org.instructure.Documents
+
 import echo.org.plugins.*
 import io.ktor.client.request.*
 import io.ktor.client.statement.*
 import io.ktor.http.*
-import io.ktor.server.application.*
+
 import io.ktor.server.testing.*
-import org.jetbrains.exposed.sql.SchemaUtils
-import org.jetbrains.exposed.sql.transactions.transaction
-import org.koin.dsl.module
-import org.koin.ktor.plugin.Koin
 import kotlin.test.*
 
 class ApplicationTest {