diff --git a/lib/famedlysdk.dart b/lib/famedlysdk.dart
index 8288e513..cfdf3f6c 100644
--- a/lib/famedlysdk.dart
+++ b/lib/famedlysdk.dart
@@ -24,12 +24,12 @@
 library famedlysdk;
 
 export 'package:famedlysdk/src/requests/SetPushersRequest.dart';
-export 'package:famedlysdk/src/responses/ErrorResponse.dart';
 export 'package:famedlysdk/src/responses/PushrulesResponse.dart';
 export 'package:famedlysdk/src/sync/RoomUpdate.dart';
 export 'package:famedlysdk/src/sync/EventUpdate.dart';
 export 'package:famedlysdk/src/sync/UserUpdate.dart';
 export 'package:famedlysdk/src/utils/ChatTime.dart';
+export 'package:famedlysdk/src/utils/MatrixException.dart';
 export 'package:famedlysdk/src/utils/MatrixFile.dart';
 export 'package:famedlysdk/src/utils/MxContent.dart';
 export 'package:famedlysdk/src/utils/StatesMap.dart';
diff --git a/lib/src/Client.dart b/lib/src/Client.dart
index b61884b0..d6e8e799 100644
--- a/lib/src/Client.dart
+++ b/lib/src/Client.dart
@@ -38,7 +38,6 @@ import 'RoomList.dart';
 import 'RoomState.dart';
 import 'User.dart';
 import 'requests/SetPushersRequest.dart';
-import 'responses/ErrorResponse.dart';
 import 'responses/PushrulesResponse.dart';
 import 'utils/Profile.dart';
 
@@ -156,65 +155,56 @@ class Client {
   /// Checks the supported versions of the Matrix protocol and the supported
   /// login types. Returns false if the server is not compatible with the
   /// client. Automatically sets [matrixVersions] and [lazyLoadMembers].
+  /// Throws FormatException, TimeoutException and MatrixException on error.
   Future<bool> checkServer(serverUrl) async {
-    homeserver = serverUrl;
+    try {
+      homeserver = serverUrl;
+      final versionResp = await connection.jsonRequest(
+          type: HTTPType.GET, action: "/client/versions");
 
-    final versionResp = await connection.jsonRequest(
-        type: HTTPType.GET, action: "/client/versions");
-    if (versionResp is ErrorResponse) {
-      connection.onError.add(ErrorResponse(errcode: "NO_RESPONSE", error: ""));
-      return false;
-    }
+      final List<String> versions = List<String>.from(versionResp["versions"]);
 
-    final List<String> versions = List<String>.from(versionResp["versions"]);
-
-    if (versions == null) {
-      connection.onError.add(ErrorResponse(errcode: "NO_RESPONSE", error: ""));
-      return false;
-    }
-
-    for (int i = 0; i < versions.length; i++) {
-      if (versions[i] == "r0.5.0")
-        break;
-      else if (i == versions.length - 1) {
-        connection.onError.add(ErrorResponse(errcode: "NO_SUPPORT", error: ""));
-        return false;
+      for (int i = 0; i < versions.length; i++) {
+        if (versions[i] == "r0.5.0")
+          break;
+        else if (i == versions.length - 1) {
+          return false;
+        }
       }
-    }
 
-    matrixVersions = versions;
+      matrixVersions = versions;
 
-    if (versionResp.containsKey("unstable_features") &&
-        versionResp["unstable_features"].containsKey("m.lazy_load_members")) {
-      lazyLoadMembers = versionResp["unstable_features"]["m.lazy_load_members"]
-          ? true
-          : false;
-    }
-
-    final loginResp = await connection.jsonRequest(
-        type: HTTPType.GET, action: "/client/r0/login");
-    if (loginResp is ErrorResponse) {
-      connection.onError.add(loginResp);
-      return false;
-    }
-
-    final List<dynamic> flows = loginResp["flows"];
-
-    for (int i = 0; i < flows.length; i++) {
-      if (flows[i].containsKey("type") &&
-          flows[i]["type"] == "m.login.password")
-        break;
-      else if (i == flows.length - 1) {
-        connection.onError.add(ErrorResponse(errcode: "NO_SUPPORT", error: ""));
-        return false;
+      if (versionResp.containsKey("unstable_features") &&
+          versionResp["unstable_features"].containsKey("m.lazy_load_members")) {
+        lazyLoadMembers = versionResp["unstable_features"]
+                ["m.lazy_load_members"]
+            ? true
+            : false;
       }
-    }
 
-    return true;
+      final loginResp = await connection.jsonRequest(
+          type: HTTPType.GET, action: "/client/r0/login");
+
+      final List<dynamic> flows = loginResp["flows"];
+
+      for (int i = 0; i < flows.length; i++) {
+        if (flows[i].containsKey("type") &&
+            flows[i]["type"] == "m.login.password")
+          break;
+        else if (i == flows.length - 1) {
+          return false;
+        }
+      }
+      return true;
+    } catch (_) {
+      this.homeserver = this.matrixVersions = null;
+      rethrow;
+    }
   }
 
   /// Handles the login and allows the client to call all APIs which require
-  /// authentication. Returns false if the login was not successful.
+  /// authentication. Returns false if the login was not successful. Throws
+  /// MatrixException if login was not successful.
   Future<bool> login(String username, String password) async {
     final loginResp = await connection
         .jsonRequest(type: HTTPType.POST, action: "/client/r0/login", data: {
@@ -228,15 +218,10 @@ class Client {
       "initial_device_display_name": "Famedly Talk"
     });
 
-    if (loginResp is ErrorResponse) {
-      connection.onError.add(loginResp);
-      return false;
-    }
-
     final userID = loginResp["user_id"];
     final accessToken = loginResp["access_token"];
     if (userID == null || accessToken == null) {
-      connection.onError.add(ErrorResponse(errcode: "NO_SUPPORT", error: ""));
+      return false;
     }
 
     await connection.connect(
@@ -253,11 +238,14 @@ class Client {
   /// Sends a logout command to the homeserver and clears all local data,
   /// including all persistent data from the store.
   Future<void> logout() async {
-    final dynamic resp = await connection.jsonRequest(
-        type: HTTPType.POST, action: "/client/r0/logout");
-    if (resp is ErrorResponse) connection.onError.add(resp);
-
-    await connection.clear();
+    try {
+      await connection.jsonRequest(
+          type: HTTPType.POST, action: "/client/r0/logout");
+    } catch (exception) {
+      rethrow;
+    } finally {
+      await connection.clear();
+    }
   }
 
   /// Get the combined profile information for this user. This API may be used to
@@ -266,10 +254,6 @@ class Client {
   Future<Profile> getProfileFromUserId(String userId) async {
     final dynamic resp = await connection.jsonRequest(
         type: HTTPType.GET, action: "/client/r0/profile/${userId}");
-    if (resp is ErrorResponse) {
-      connection.onError.add(resp);
-      return null;
-    }
     return Profile.fromJson(resp);
   }
 
@@ -295,8 +279,7 @@ class Client {
     String action = "/client/r0/sync?filter=$syncFilters&timeout=0";
     final sync =
         await connection.jsonRequest(type: HTTPType.GET, action: action);
-    if (!(sync is ErrorResponse) &&
-        sync["rooms"]["leave"] is Map<String, dynamic>) {
+    if (sync["rooms"]["leave"] is Map<String, dynamic>) {
       for (var entry in sync["rooms"]["leave"].entries) {
         final String id = entry.key;
         final dynamic room = entry.value;
@@ -377,33 +360,29 @@ class Client {
     if (params == null && invite != null)
       for (int i = 0; i < invite.length; i++) inviteIDs.add(invite[i].id);
 
-    final dynamic resp = await connection.jsonRequest(
-        type: HTTPType.POST,
-        action: "/client/r0/createRoom",
-        data: params == null
-            ? {
-                "invite": inviteIDs,
-              }
-            : params);
-
-    if (resp is ErrorResponse) {
-      connection.onError.add(resp);
-      return null;
+    try {
+      final dynamic resp = await connection.jsonRequest(
+          type: HTTPType.POST,
+          action: "/client/r0/createRoom",
+          data: params == null
+              ? {
+                  "invite": inviteIDs,
+                }
+              : params);
+      return resp["room_id"];
+    } catch (e) {
+      rethrow;
     }
-
-    return resp["room_id"];
   }
 
-  /// Uploads a new user avatar for this user. Returns ErrorResponse if something went wrong.
-  Future<dynamic> setAvatar(MatrixFile file) async {
+  /// Uploads a new user avatar for this user.
+  Future<void> setAvatar(MatrixFile file) async {
     final uploadResp = await connection.upload(file);
-    if (uploadResp is ErrorResponse) return uploadResp;
-    final setAvatarResp = await connection.jsonRequest(
+    await connection.jsonRequest(
         type: HTTPType.PUT,
         action: "/client/r0/profile/$userID/avatar_url",
         data: {"avatar_url": uploadResp});
-    if (setAvatarResp is ErrorResponse) return setAvatarResp;
-    return null;
+    return;
   }
 
   /// Fetches the pushrules for the logged in user.
@@ -414,26 +393,16 @@ class Client {
       action: "/client/r0/pushrules/",
     );
 
-    if (resp is ErrorResponse) {
-      connection.onError.add(resp);
-      return null;
-    }
-
     return PushrulesResponse.fromJson(resp);
   }
 
   /// This endpoint allows the creation, modification and deletion of pushers for this user ID.
-  Future<dynamic> setPushers(SetPushersRequest data) async {
-    final dynamic resp = await connection.jsonRequest(
+  Future<void> setPushers(SetPushersRequest data) async {
+    await connection.jsonRequest(
       type: HTTPType.POST,
       action: "/client/r0/pushers/set",
       data: data.toJson(),
     );
-
-    if (resp is ErrorResponse) {
-      connection.onError.add(resp);
-    }
-
-    return resp;
+    return;
   }
 }
diff --git a/lib/src/Connection.dart b/lib/src/Connection.dart
index d201b796..52ff6adc 100644
--- a/lib/src/Connection.dart
+++ b/lib/src/Connection.dart
@@ -33,10 +33,10 @@ import 'package:mime_type/mime_type.dart';
 
 import 'Client.dart';
 import 'User.dart';
-import 'responses/ErrorResponse.dart';
 import 'sync/EventUpdate.dart';
 import 'sync/RoomUpdate.dart';
 import 'sync/UserUpdate.dart';
+import 'utils/MatrixException.dart';
 
 enum HTTPType { GET, POST, PUT, DELETE }
 
@@ -74,7 +74,7 @@ class Connection {
       new StreamController.broadcast();
 
   /// Synchronization erros are coming here.
-  final StreamController<ErrorResponse> onError =
+  final StreamController<MatrixException> onError =
       new StreamController.broadcast();
 
   /// This is called once, when the first sync has received.
@@ -177,6 +177,8 @@ class Connection {
 
   /// Used for all Matrix json requests using the [c2s API](https://matrix.org/docs/spec/client_server/r0.4.0.html).
   ///
+  /// Throws: TimeoutException, FormatException, MatrixException
+  ///
   /// You must first call [this.connect()] or set [this.homeserver] before you can use
   /// this! For example to send a message to a Matrix room with the id
   /// '!fjd823j:example.com' you call:
@@ -192,7 +194,7 @@ class Connection {
   ///  );
   /// ```
   ///
-  Future<dynamic> jsonRequest(
+  Future<Map<String, dynamic>> jsonRequest(
       {HTTPType type,
       String action,
       dynamic data = "",
@@ -219,6 +221,7 @@ class Connection {
           "[REQUEST ${type.toString().split('.').last}] Action: $action, Data: $data");
 
     http.Response resp;
+    Map<String, dynamic> jsonResp = {};
     try {
       switch (type.toString().split('.').last) {
         case "GET":
@@ -242,52 +245,47 @@ class Connection {
               .timeout(Duration(seconds: timeout));
           break;
       }
-    } on TimeoutException catch (_) {
-      return ErrorResponse(
-          error: "No connection possible...",
-          errcode: "TIMEOUT",
-          request: resp?.request);
-    } catch (e) {
-      return ErrorResponse(
-          error: "No connection possible...",
-          errcode: "NO_CONNECTION",
-          request: resp?.request);
-    }
+      jsonResp = jsonDecode(resp.body)
+          as Map<String, dynamic>; // May throw FormatException
 
-    Map<String, dynamic> jsonResp;
-    try {
-      jsonResp = jsonDecode(resp.body) as Map<String, dynamic>;
-    } catch (e) {
-      return ErrorResponse(
-          error: "No connection possible...",
-          errcode: "MALFORMED",
-          request: resp?.request);
-    }
-    if (jsonResp.containsKey("errcode") && jsonResp["errcode"] is String) {
-      if (jsonResp["errcode"] == "M_UNKNOWN_TOKEN") clear();
-      return ErrorResponse.fromJson(jsonResp, resp?.request);
-    }
+      if (jsonResp.containsKey("errcode") && jsonResp["errcode"] is String) {
+        // The server has responsed with an matrix related error.
+        MatrixException exception = MatrixException(resp);
+        if (exception.error == MatrixError.M_UNKNOWN_TOKEN) {
+          // The token is no longer valid. Need to sign off....
+          onError.add(exception);
+          clear();
+        }
 
-    if (client.debug) print("[RESPONSE] ${jsonResp.toString()}");
+        throw exception;
+      }
+
+      if (client.debug) print("[RESPONSE] ${jsonResp.toString()}");
+    } on ArgumentError catch (exception) {
+      print(exception);
+      // Ignore this error
+    } catch (_) {
+      print(_);
+      rethrow;
+    }
 
     return jsonResp;
   }
 
   /// Uploads a file with the name [fileName] as base64 encoded to the server
-  /// and returns the mxc url as a string or an [ErrorResponse].
-  Future<dynamic> upload(MatrixFile file) async {
+  /// and returns the mxc url as a string.
+  Future<String> upload(MatrixFile file) async {
     dynamic fileBytes;
     if (client.homeserver != "https://fakeServer.notExisting")
       fileBytes = file.bytes;
     String fileName = file.path.split("/").last.toLowerCase();
     String mimeType = mime(file.path);
     print("[UPLOADING] $fileName, type: $mimeType, size: ${fileBytes?.length}");
-    final dynamic resp = await jsonRequest(
+    final Map<String, dynamic> resp = await jsonRequest(
         type: HTTPType.POST,
         action: "/media/r0/upload?filename=$fileName",
         data: fileBytes,
         contentType: mimeType);
-    if (resp is ErrorResponse) return resp;
     return resp["content_uri"];
   }
 
@@ -302,32 +300,28 @@ class Connection {
       action += "&timeout=30000";
       action += "&since=${client.prevBatch}";
     }
-    _syncRequest = jsonRequest(type: HTTPType.GET, action: action);
-    final int hash = _syncRequest.hashCode;
-    final syncResp = await _syncRequest;
-    if (hash != _syncRequest.hashCode) return;
-    if (syncResp is ErrorResponse) {
-      //onError.add(syncResp);
-      await Future.delayed(Duration(seconds: syncErrorTimeoutSec), () {});
-    } else {
-      try {
-        if (client.store != null)
-          await client.store.transaction(() {
-            handleSync(syncResp);
-            client.store.storePrevBatch(syncResp);
-            return;
-          });
-        else
-          await handleSync(syncResp);
-        if (client.prevBatch == null) client.connection.onFirstSync.add(true);
-        client.prevBatch = syncResp["next_batch"];
-      } catch (e) {
-        onError
-            .add(ErrorResponse(errcode: "CRITICAL_ERROR", error: e.toString()));
-        await Future.delayed(Duration(seconds: syncErrorTimeoutSec), () {});
-      }
+    try {
+      _syncRequest = jsonRequest(type: HTTPType.GET, action: action);
+      final int hash = _syncRequest.hashCode;
+      final syncResp = await _syncRequest;
+      if (hash != _syncRequest.hashCode) return;
+      if (client.store != null)
+        await client.store.transaction(() {
+          handleSync(syncResp);
+          client.store.storePrevBatch(syncResp);
+          return;
+        });
+      else
+        await handleSync(syncResp);
+      if (client.prevBatch == null) client.connection.onFirstSync.add(true);
+      client.prevBatch = syncResp["next_batch"];
+      if (hash == _syncRequest.hashCode) _sync();
+    } on MatrixException catch (exception) {
+      onError.add(exception);
+      await Future.delayed(Duration(seconds: syncErrorTimeoutSec), _sync);
+    } catch (exception) {
+      await Future.delayed(Duration(seconds: syncErrorTimeoutSec), _sync);
     }
-    if (hash == _syncRequest.hashCode) _sync();
   }
 
   void handleSync(dynamic sync) {
diff --git a/lib/src/Room.dart b/lib/src/Room.dart
index 14950817..55b71c1e 100644
--- a/lib/src/Room.dart
+++ b/lib/src/Room.dart
@@ -25,10 +25,10 @@ import 'package:famedlysdk/src/Client.dart';
 import 'package:famedlysdk/src/Event.dart';
 import 'package:famedlysdk/src/RoomAccountData.dart';
 import 'package:famedlysdk/src/RoomState.dart';
-import 'package:famedlysdk/src/responses/ErrorResponse.dart';
 import 'package:famedlysdk/src/sync/EventUpdate.dart';
 import 'package:famedlysdk/src/sync/RoomUpdate.dart';
 import 'package:famedlysdk/src/utils/ChatTime.dart';
+import 'package:famedlysdk/src/utils/MatrixException.dart';
 import 'package:famedlysdk/src/utils/MatrixFile.dart';
 import 'package:famedlysdk/src/utils/MxContent.dart';
 //import 'package:image/image.dart';
@@ -248,35 +248,33 @@ class Room {
       return ChatTime.now();
   }
 
-  /// Call the Matrix API to change the name of this room.
-  Future<dynamic> setName(String newName) async {
-    dynamic res = await client.connection.jsonRequest(
+  /// Call the Matrix API to change the name of this room. Returns the event ID of the
+  /// new m.room.name event.
+  Future<String> setName(String newName) async {
+    final Map<String, dynamic> resp = await client.connection.jsonRequest(
         type: HTTPType.PUT,
         action: "/client/r0/rooms/${id}/state/m.room.name",
         data: {"name": newName});
-    if (res is ErrorResponse) client.connection.onError.add(res);
-    return res;
+    return resp["event_id"];
   }
 
   /// Call the Matrix API to change the topic of this room.
-  Future<dynamic> setDescription(String newName) async {
-    dynamic res = await client.connection.jsonRequest(
+  Future<String> setDescription(String newName) async {
+    final Map<String, dynamic> resp = await client.connection.jsonRequest(
         type: HTTPType.PUT,
         action: "/client/r0/rooms/${id}/state/m.room.topic",
         data: {"topic": newName});
-    if (res is ErrorResponse) client.connection.onError.add(res);
-    return res;
+    return resp["event_id"];
   }
 
-  Future<dynamic> _sendRawEventNow(Map<String, dynamic> content,
+  Future<String> _sendRawEventNow(Map<String, dynamic> content,
       {String txid = null}) async {
     if (txid == null) txid = "txid${DateTime.now().millisecondsSinceEpoch}";
-    final dynamic res = await client.connection.jsonRequest(
+    final Map<String, dynamic> res = await client.connection.jsonRequest(
         type: HTTPType.PUT,
         action: "/client/r0/rooms/${id}/send/m.room.message/$txid",
         data: content);
-    if (res is ErrorResponse) client.connection.onError.add(res);
-    return res;
+    return res["event_id"];
   }
 
   Future<String> sendTextEvent(String message, {String txid = null}) =>
@@ -291,8 +289,7 @@ class Room {
     if (msgType == "m.video") return sendAudioEvent(file);
     String fileName = file.path.split("/").last;
 
-    final dynamic uploadResp = await client.connection.upload(file);
-    if (uploadResp is ErrorResponse) return null;
+    final String uploadResp = await client.connection.upload(file);
 
     // Send event
     Map<String, dynamic> content = {
@@ -311,8 +308,7 @@ class Room {
   Future<String> sendAudioEvent(MatrixFile file,
       {String txid = null, int width, int height}) async {
     String fileName = file.path.split("/").last;
-    final dynamic uploadResp = await client.connection.upload(file);
-    if (uploadResp is ErrorResponse) return null;
+    final String uploadResp = await client.connection.upload(file);
     Map<String, dynamic> content = {
       "msgtype": "m.audio",
       "body": fileName,
@@ -329,8 +325,7 @@ class Room {
   Future<String> sendImageEvent(MatrixFile file,
       {String txid = null, int width, int height}) async {
     String fileName = file.path.split("/").last;
-    final dynamic uploadResp = await client.connection.upload(file);
-    if (uploadResp is ErrorResponse) return null;
+    final String uploadResp = await client.connection.upload(file);
     Map<String, dynamic> content = {
       "msgtype": "m.image",
       "body": fileName,
@@ -354,8 +349,7 @@ class Room {
       int thumbnailWidth,
       int thumbnailHeight}) async {
     String fileName = file.path.split("/").last;
-    final dynamic uploadResp = await client.connection.upload(file);
-    if (uploadResp is ErrorResponse) return null;
+    final String uploadResp = await client.connection.upload(file);
     Map<String, dynamic> content = {
       "msgtype": "m.video",
       "body": fileName,
@@ -376,8 +370,7 @@ class Room {
     }
     if (thumbnail != null) {
       String thumbnailName = file.path.split("/").last;
-      final dynamic thumbnailUploadResp = await client.connection.upload(file);
-      if (thumbnailUploadResp is ErrorResponse) return null;
+      final String thumbnailUploadResp = await client.connection.upload(file);
       content["info"]["thumbnail_url"] = thumbnailUploadResp;
       content["info"]["thumbnail_info"] = {
         "size": thumbnail.size,
@@ -422,9 +415,18 @@ class Room {
     });
 
     // Send the text and on success, store and display a *sent* event.
-    final dynamic res = await _sendRawEventNow(content, txid: messageID);
-
-    if (res is ErrorResponse || !(res["event_id"] is String)) {
+    try {
+      final String res = await _sendRawEventNow(content, txid: messageID);
+      eventUpdate.content["status"] = 1;
+      eventUpdate.content["unsigned"] = {"transaction_id": messageID};
+      eventUpdate.content["event_id"] = res;
+      client.connection.onEvent.add(eventUpdate);
+      await client.store?.transaction(() {
+        client.store.storeEventUpdate(eventUpdate);
+        return;
+      });
+      return res;
+    } catch (exception) {
       // On error, set status to -1
       eventUpdate.content["status"] = -1;
       eventUpdate.content["unsigned"] = {"transaction_id": messageID};
@@ -433,16 +435,6 @@ class Room {
         client.store.storeEventUpdate(eventUpdate);
         return;
       });
-    } else {
-      eventUpdate.content["status"] = 1;
-      eventUpdate.content["unsigned"] = {"transaction_id": messageID};
-      eventUpdate.content["event_id"] = res["event_id"];
-      client.connection.onEvent.add(eventUpdate);
-      await client.store?.transaction(() {
-        client.store.storeEventUpdate(eventUpdate);
-        return;
-      });
-      return res["event_id"];
     }
     return null;
   }
@@ -450,12 +442,16 @@ class Room {
   /// Call the Matrix API to join this room if the user is not already a member.
   /// If this room is intended to be a direct chat, the direct chat flag will
   /// automatically be set.
-  Future<dynamic> join() async {
-    dynamic res = await client.connection.jsonRequest(
-        type: HTTPType.POST, action: "/client/r0/rooms/${id}/join");
-    if (res is ErrorResponse) {
-      client.connection.onError.add(res);
-      if (res.error == "No known servers") {
+  Future<void> join() async {
+    try {
+      await client.connection.jsonRequest(
+          type: HTTPType.POST, action: "/client/r0/rooms/${id}/join");
+      if (states.containsKey(client.userID) &&
+          states[client.userID].content["is_direct"] is bool &&
+          states[client.userID].content["is_direct"])
+        addToDirectChat(states[client.userID].sender.id);
+    } on MatrixException catch (exception) {
+      if (exception.errorMessage == "No known servers") {
         client.store?.forgetRoom(id);
         client.connection.onRoomUpdate.add(
           RoomUpdate(
@@ -465,88 +461,78 @@ class Room {
               highlight_count: 0),
         );
       }
-      return res;
+      rethrow;
     }
-    if (states.containsKey(client.userID) &&
-        states[client.userID].content["is_direct"] is bool &&
-        states[client.userID].content["is_direct"])
-      addToDirectChat(states[client.userID].sender.id);
-    return res;
   }
 
   /// Call the Matrix API to leave this room. If this room is set as a direct
   /// chat, this will be removed too.
-  Future<dynamic> leave() async {
+  Future<void> leave() async {
     if (directChatMatrixID != "") await removeFromDirectChat();
-    dynamic res = await client.connection.jsonRequest(
+    await client.connection.jsonRequest(
         type: HTTPType.POST, action: "/client/r0/rooms/${id}/leave");
-    if (res is ErrorResponse) client.connection.onError.add(res);
-    return res;
+    return;
   }
 
   /// Call the Matrix API to forget this room if you already left it.
-  Future<dynamic> forget() async {
+  Future<void> forget() async {
     client.store.forgetRoom(id);
-    dynamic res = await client.connection.jsonRequest(
+    await client.connection.jsonRequest(
         type: HTTPType.POST, action: "/client/r0/rooms/${id}/forget");
-    if (res is ErrorResponse) client.connection.onError.add(res);
-    return res;
+    return;
   }
 
   /// Call the Matrix API to kick a user from this room.
-  Future<dynamic> kick(String userID) async {
-    dynamic res = await client.connection.jsonRequest(
+  Future<void> kick(String userID) async {
+    await client.connection.jsonRequest(
         type: HTTPType.POST,
         action: "/client/r0/rooms/${id}/kick",
         data: {"user_id": userID});
-    if (res is ErrorResponse) client.connection.onError.add(res);
-    return res;
+    return;
   }
 
   /// Call the Matrix API to ban a user from this room.
-  Future<dynamic> ban(String userID) async {
-    dynamic res = await client.connection.jsonRequest(
+  Future<void> ban(String userID) async {
+    await client.connection.jsonRequest(
         type: HTTPType.POST,
         action: "/client/r0/rooms/${id}/ban",
         data: {"user_id": userID});
-    if (res is ErrorResponse) client.connection.onError.add(res);
-    return res;
+    return;
   }
 
   /// Call the Matrix API to unban a banned user from this room.
-  Future<dynamic> unban(String userID) async {
-    dynamic res = await client.connection.jsonRequest(
+  Future<void> unban(String userID) async {
+    await client.connection.jsonRequest(
         type: HTTPType.POST,
         action: "/client/r0/rooms/${id}/unban",
         data: {"user_id": userID});
-    if (res is ErrorResponse) client.connection.onError.add(res);
-    return res;
+    return;
   }
 
   /// Set the power level of the user with the [userID] to the value [power].
-  Future<dynamic> setPower(String userID, int power) async {
+  /// Returns the event ID of the new state event. If there is no known
+  /// power level event, there might something broken and this returns null.
+  Future<String> setPower(String userID, int power) async {
     if (states["m.room.power_levels"] == null) return null;
     Map<String, dynamic> powerMap = {}
       ..addAll(states["m.room.power_levels"].content);
     if (powerMap["users"] == null) powerMap["users"] = {};
     powerMap["users"][userID] = power;
 
-    dynamic res = await client.connection.jsonRequest(
+    final Map<String, dynamic> resp = await client.connection.jsonRequest(
         type: HTTPType.PUT,
         action: "/client/r0/rooms/$id/state/m.room.power_levels",
         data: powerMap);
-    if (res is ErrorResponse) client.connection.onError.add(res);
-    return res;
+    return resp["event_id"];
   }
 
   /// Call the Matrix API to invite a user to this room.
-  Future<dynamic> invite(String userID) async {
-    dynamic res = await client.connection.jsonRequest(
+  Future<void> invite(String userID) async {
+    await client.connection.jsonRequest(
         type: HTTPType.POST,
         action: "/client/r0/rooms/${id}/invite",
         data: {"user_id": userID});
-    if (res is ErrorResponse) client.connection.onError.add(res);
-    return res;
+    return;
   }
 
   /// Request more previous events from the server. [historyCount] defines how much events should
@@ -559,8 +545,6 @@ class Room {
         action:
             "/client/r0/rooms/$id/messages?from=${prev_batch}&dir=b&limit=$historyCount&filter=${Connection.syncFilters}");
 
-    if (resp is ErrorResponse) return;
-
     if (onHistoryReceived != null) onHistoryReceived();
     prev_batch = resp["end"];
     client.store?.storeRoomPrevBatch(this);
@@ -634,51 +618,51 @@ class Room {
     );
   }
 
-  /// Sets this room as a direct chat for this user.
-  Future<dynamic> addToDirectChat(String userID) async {
+  /// Sets this room as a direct chat for this user if not already.
+  Future<void> addToDirectChat(String userID) async {
     Map<String, dynamic> directChats = client.directChats;
     if (directChats.containsKey(userID)) if (!directChats[userID].contains(id))
       directChats[userID].add(id);
     else
-      return null; // Is already in direct chats
+      return; // Is already in direct chats
     else
       directChats[userID] = [id];
 
-    final resp = await client.connection.jsonRequest(
+    await client.connection.jsonRequest(
         type: HTTPType.PUT,
         action: "/client/r0/user/${client.userID}/account_data/m.direct",
         data: directChats);
-    return resp;
+    return;
   }
 
-  /// Sets this room as a direct chat for this user.
-  Future<dynamic> removeFromDirectChat() async {
+  /// Removes this room from all direct chat tags.
+  Future<void> removeFromDirectChat() async {
     Map<String, dynamic> directChats = client.directChats;
     if (directChats.containsKey(directChatMatrixID) &&
         directChats[directChatMatrixID].contains(id))
       directChats[directChatMatrixID].remove(id);
     else
-      return null; // Nothing to do here
+      return; // Nothing to do here
 
-    final resp = await client.connection.jsonRequest(
+    await client.connection.jsonRequest(
         type: HTTPType.PUT,
         action: "/client/r0/user/${client.userID}/account_data/m.direct",
         data: directChats);
-    return resp;
+    return;
   }
 
   /// Sends *m.fully_read* and *m.read* for the given event ID.
-  Future<dynamic> sendReadReceipt(String eventID) async {
+  Future<void> sendReadReceipt(String eventID) async {
     this.notificationCount = 0;
     client?.store?.resetNotificationCount(this.id);
-    final dynamic resp = client.connection.jsonRequest(
+    client.connection.jsonRequest(
         type: HTTPType.POST,
         action: "/client/r0/rooms/$id/read_markers",
         data: {
           "m.fully_read": eventID,
           "m.read": eventID,
         });
-    return resp;
+    return;
   }
 
   /// Returns a Room from a json String which comes normally from the store. If the
@@ -770,8 +754,6 @@ class Room {
 
     dynamic res = await client.connection.jsonRequest(
         type: HTTPType.GET, action: "/client/r0/rooms/${id}/members");
-    if (res is ErrorResponse || !(res["chunk"] is List<dynamic>))
-      return participants;
 
     for (num i = 0; i < res["chunk"].length; i++) {
       User newUser = RoomState.fromJson(res["chunk"][i], this).asUser;
@@ -794,7 +776,9 @@ class Room {
     if (states[mxID] != null)
       return states[mxID].asUser;
     else {
-      requestUser(mxID);
+      try {
+        requestUser(mxID);
+      } catch (_) {}
       return User(mxID, room: this);
     }
   }
@@ -805,12 +789,14 @@ class Room {
   /// lazy loading.
   Future<User> requestUser(String mxID) async {
     if (mxID == null || !_requestingMatrixIds.add(mxID)) return null;
-    final dynamic resp = await client.connection.jsonRequest(
-        type: HTTPType.GET,
-        action: "/client/r0/rooms/$id/state/m.room.member/$mxID");
-    if (resp is ErrorResponse) {
+    Map<String, dynamic> resp;
+    try {
+      resp = await client.connection.jsonRequest(
+          type: HTTPType.GET,
+          action: "/client/r0/rooms/$id/state/m.room.member/$mxID");
+    } catch (exception) {
       _requestingMatrixIds.remove(mxID);
-      return null;
+      rethrow;
     }
     final User user = User(mxID,
         displayName: resp["displayname"],
@@ -837,7 +823,6 @@ class Room {
   Future<Event> getEventById(String eventID) async {
     final dynamic resp = await client.connection.jsonRequest(
         type: HTTPType.GET, action: "/client/r0/rooms/$id/event/$eventID");
-    if (resp is ErrorResponse) return null;
     return Event.fromJson(resp, this);
   }
 
@@ -865,16 +850,15 @@ class Room {
     return null;
   }
 
-  /// Uploads a new user avatar for this room. Returns ErrorResponse if something went wrong
-  /// and the event ID otherwise.
-  Future<dynamic> setAvatar(MatrixFile file) async {
-    final uploadResp = await client.connection.upload(file);
-    if (uploadResp is ErrorResponse) return uploadResp;
-    final setAvatarResp = await client.connection.jsonRequest(
-        type: HTTPType.PUT,
-        action: "/client/r0/rooms/$id/state/m.room.avatar/",
-        data: {"url": uploadResp});
-    if (setAvatarResp is ErrorResponse) return setAvatarResp;
+  /// Uploads a new user avatar for this room. Returns the event ID of the new
+  /// m.room.avatar event.
+  Future<String> setAvatar(MatrixFile file) async {
+    final String uploadResp = await client.connection.upload(file);
+    final Map<String, dynamic> setAvatarResp = await client.connection
+        .jsonRequest(
+            type: HTTPType.PUT,
+            action: "/client/r0/rooms/$id/state/m.room.avatar/",
+            data: {"url": uploadResp});
     return setAvatarResp["event_id"];
   }
 
@@ -979,7 +963,6 @@ class Room {
               type: HTTPType.DELETE,
               action: "/client/r0/pushrules/global/override/$id",
               data: {});
-          if (resp == ErrorResponse) return resp;
           resp = await client.connection.jsonRequest(
               type: HTTPType.PUT,
               action: "/client/r0/pushrules/global/room/$id",
@@ -1001,7 +984,6 @@ class Room {
               type: HTTPType.DELETE,
               action: "/client/r0/pushrules/global/room/$id",
               data: {});
-          if (resp == ErrorResponse) return resp;
         }
         resp = await client.connection.jsonRequest(
             type: HTTPType.PUT,
diff --git a/lib/src/User.dart b/lib/src/User.dart
index da373f09..5108a2eb 100644
--- a/lib/src/User.dart
+++ b/lib/src/User.dart
@@ -24,7 +24,6 @@
 import 'package:famedlysdk/famedlysdk.dart';
 import 'package:famedlysdk/src/Room.dart';
 import 'package:famedlysdk/src/RoomState.dart';
-import 'package:famedlysdk/src/responses/ErrorResponse.dart';
 import 'package:famedlysdk/src/utils/ChatTime.dart';
 import 'package:famedlysdk/src/utils/MxContent.dart';
 
@@ -113,28 +112,16 @@ class User extends RoomState {
       : displayName;
 
   /// Call the Matrix API to kick this user from this room.
-  Future<dynamic> kick() async {
-    dynamic res = await room.kick(id);
-    return res;
-  }
+  Future<void> kick() => room.kick(id);
 
   /// Call the Matrix API to ban this user from this room.
-  Future<dynamic> ban() async {
-    dynamic res = await room.ban(id);
-    return res;
-  }
+  Future<void> ban() => room.ban(id);
 
   /// Call the Matrix API to unban this banned user from this room.
-  Future<dynamic> unban() async {
-    dynamic res = await room.unban(id);
-    return res;
-  }
+  Future<void> unban() => room.unban(id);
 
   /// Call the Matrix API to change the power level of this user.
-  Future<dynamic> setPower(int power) async {
-    dynamic res = await room.setPower(id, power);
-    return res;
-  }
+  Future<void> setPower(int power) => room.setPower(id, power);
 
   /// Returns an existing direct chat ID with this user or creates a new one.
   /// Returns null on error.
@@ -153,11 +140,6 @@ class User extends RoomState {
           "preset": "trusted_private_chat"
         });
 
-    if (resp is ErrorResponse) {
-      room.client.connection.onError.add(resp);
-      return null;
-    }
-
     final String newRoomID = resp["room_id"];
 
     if (newRoomID == null) return newRoomID;
diff --git a/lib/src/responses/ErrorResponse.dart b/lib/src/responses/ErrorResponse.dart
deleted file mode 100644
index ff674be6..00000000
--- a/lib/src/responses/ErrorResponse.dart
+++ /dev/null
@@ -1,51 +0,0 @@
-/*
- * Copyright (c) 2019 Zender & Kurtz GbR.
- *
- * Authors:
- *   Christian Pauly <krille@famedly.com>
- *   Marcel Radzio <mtrnord@famedly.com>
- *
- * This file is part of famedlysdk.
- *
- * famedlysdk is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * famedlysdk is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with famedlysdk.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-import 'package:http/http.dart' as http;
-
-/// Represents a special response from the Homeserver for errors.
-class ErrorResponse {
-  /// The unique identifier for this error.
-  String errcode;
-
-  /// A human readable error description.
-  String error;
-
-  /// The frozen request which triggered this Error
-  http.Request request;
-
-  ErrorResponse({this.errcode, this.error, this.request});
-
-  ErrorResponse.fromJson(Map<String, dynamic> json, http.Request newRequest) {
-    errcode = json['errcode'];
-    error = json['error'] ?? "";
-    request = newRequest;
-  }
-
-  Map<String, dynamic> toJson() {
-    final Map<String, dynamic> data = new Map<String, dynamic>();
-    data['errcode'] = this.errcode;
-    data['error'] = this.error;
-    return data;
-  }
-}
diff --git a/lib/src/utils/MatrixException.dart b/lib/src/utils/MatrixException.dart
new file mode 100644
index 00000000..f542148e
--- /dev/null
+++ b/lib/src/utils/MatrixException.dart
@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2019 Zender & Kurtz GbR.
+ *
+ * Authors:
+ *   Christian Pauly <krille@famedly.com>
+ *   Marcel Radzio <mtrnord@famedly.com>
+ *
+ * This file is part of famedlysdk.
+ *
+ * famedlysdk is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * famedlysdk is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with famedlysdk.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import 'dart:convert';
+
+import 'package:http/http.dart' as http;
+
+enum MatrixError {
+  M_UNKNOWN,
+  M_UNKNOWN_TOKEN,
+  M_NOT_FOUND,
+  M_FORBIDDEN,
+  M_LIMIT_EXCEEDED,
+  M_USER_IN_USE,
+  M_THREEPID_IN_USE,
+  M_THREEPID_DENIED,
+  M_THREEPID_NOT_FOUND,
+  M_THREEPID_AUTH_FAILED,
+  M_TOO_LARGE,
+  M_MISSING_PARAM,
+  M_UNSUPPORTED_ROOM_VERSION,
+  M_UNRECOGNIZED,
+}
+
+/// Represents a special response from the Homeserver for errors.
+class MatrixException implements Exception {
+  final Map<String, dynamic> raw;
+
+  /// The unique identifier for this error.
+  String get errcode => raw["errcode"];
+
+  /// A human readable error description.
+  String get errorMessage => raw["error"];
+
+  /// The frozen request which triggered this Error
+  http.Response response;
+
+  MatrixException(this.response) : this.raw = json.decode(response.body);
+
+  @override
+  String toString() => "$errcode: $errorMessage";
+
+  /// Returns the [ResponseError]. Is ResponseError.NONE if there wasn't an error.
+  MatrixError get error => MatrixError.values.firstWhere(
+      (e) => e.toString() == 'MatrixError.${(raw["errcode"] ?? "")}',
+      orElse: () => MatrixError.M_UNKNOWN);
+
+  int get retryAfterMs => raw["retry_after_ms"];
+
+  /// This is a session identifier that the client must pass back to the homeserver, if one is provided,
+  /// in subsequent attempts to authenticate in the same API call.
+  String get session => raw["session"];
+
+  /// Returns true if the server requires additional authentication.
+  bool get requireAdditionalAuthentication => response.statusCode == 401;
+
+  /// For each endpoint, a server offers one or more 'flows' that the client can use
+  /// to authenticate itself. Each flow comprises a series of stages. If this request
+  /// doesn't need additional authentication, then this is null.
+  List<AuthenticationFlow> get authenticationFlows {
+    if (!raw.containsKey("flows") || !(raw["flows"] is List)) return null;
+    List<AuthenticationFlow> flows = [];
+    for (Map<String, dynamic> flow in raw["flows"]) {
+      if (flow["stages"] is List<String>) {
+        flows.add(AuthenticationFlow(flow["stages"]));
+      }
+    }
+    return flows;
+  }
+
+  /// This section contains any information that the client will need to know in order to use a given type
+  /// of authentication. For each authentication type presented, that type may be present as a key in this
+  /// dictionary. For example, the public part of an OAuth client ID could be given here.
+  Map<String, dynamic> get authenticationParams => raw["params"];
+
+  /// Returns the list of already completed authentication flows from previous requests.
+  List<String> get completedAuthenticationFlows => raw["completed"];
+}
+
+/// For each endpoint, a server offers one or more 'flows' that the client can use
+/// to authenticate itself. Each flow comprises a series of stages
+class AuthenticationFlow {
+  final List<String> stages;
+  const AuthenticationFlow(this.stages);
+}
diff --git a/test/Client_test.dart b/test/Client_test.dart
index d646ff5c..55b43ab4 100644
--- a/test/Client_test.dart
+++ b/test/Client_test.dart
@@ -30,11 +30,11 @@ import 'package:famedlysdk/src/Presence.dart';
 import 'package:famedlysdk/src/Room.dart';
 import 'package:famedlysdk/src/User.dart';
 import 'package:famedlysdk/src/requests/SetPushersRequest.dart';
-import 'package:famedlysdk/src/responses/ErrorResponse.dart';
 import 'package:famedlysdk/src/responses/PushrulesResponse.dart';
 import 'package:famedlysdk/src/sync/EventUpdate.dart';
 import 'package:famedlysdk/src/sync/RoomUpdate.dart';
 import 'package:famedlysdk/src/sync/UserUpdate.dart';
+import 'package:famedlysdk/src/utils/MatrixException.dart';
 import 'package:famedlysdk/src/utils/MatrixFile.dart';
 import 'package:famedlysdk/src/utils/Profile.dart';
 import 'package:test/test.dart';
@@ -60,9 +60,6 @@ void main() {
     userUpdateListFuture = matrix.connection.onUserEvent.stream.toList();
 
     test('Login', () async {
-      Future<ErrorResponse> errorFuture =
-          matrix.connection.onError.stream.first;
-
       int presenceCounter = 0;
       int accountDataCounter = 0;
       matrix.onPresence = (Presence data) {
@@ -72,25 +69,26 @@ void main() {
         accountDataCounter++;
       };
 
-      final bool checkResp1 =
-          await matrix.checkServer("https://fakeserver.wrongaddress");
-      final bool checkResp2 =
-          await matrix.checkServer("https://fakeserver.notexisting");
+      expect(matrix.homeserver, null);
+      expect(matrix.matrixVersions, null);
 
-      ErrorResponse checkError = await errorFuture;
+      try {
+        await matrix.checkServer("https://fakeserver.wrongaddress");
+      } on FormatException catch (exception) {
+        expect(exception != null, true);
+      }
+      await matrix.checkServer("https://fakeserver.notexisting");
+      expect(matrix.homeserver, "https://fakeserver.notexisting");
+      expect(matrix.matrixVersions,
+          ["r0.0.1", "r0.1.0", "r0.2.0", "r0.3.0", "r0.4.0", "r0.5.0"]);
 
-      expect(checkResp1, false);
-      expect(checkResp2, true);
-      expect(checkError.errcode, "NO_RESPONSE");
-
-      final resp = await matrix.connection
+      final Map<String, dynamic> resp = await matrix.connection
           .jsonRequest(type: HTTPType.POST, action: "/client/r0/login", data: {
         "type": "m.login.password",
         "user": "test",
         "password": "1234",
         "initial_device_display_name": "Fluffy Matrix Client"
       });
-      expect(resp is ErrorResponse, false);
 
       Future<LoginState> loginStateFuture =
           matrix.connection.onLoginStateChanged.stream.first;
@@ -176,15 +174,19 @@ void main() {
     });
 
     test('Try to get ErrorResponse', () async {
-      final resp = await matrix.connection
-          .jsonRequest(type: HTTPType.PUT, action: "/non/existing/path");
-      expect(resp is ErrorResponse, true);
+      MatrixException expectedException;
+      try {
+        await matrix.connection
+            .jsonRequest(type: HTTPType.PUT, action: "/non/existing/path");
+      } on MatrixException catch (exception) {
+        expectedException = exception;
+      }
+      expect(expectedException.error, MatrixError.M_UNRECOGNIZED);
     });
 
     test('Logout', () async {
-      final dynamic resp = await matrix.connection
+      await matrix.connection
           .jsonRequest(type: HTTPType.POST, action: "/client/r0/logout");
-      expect(resp is ErrorResponse, false);
 
       Future<LoginState> loginStateFuture =
           matrix.connection.onLoginStateChanged.stream.first;
@@ -331,8 +333,7 @@ void main() {
     test('setAvatar', () async {
       final MatrixFile testFile =
           MatrixFile(bytes: [], path: "fake/path/file.jpeg");
-      final dynamic resp = await matrix.setAvatar(testFile);
-      expect(resp, null);
+      await matrix.setAvatar(testFile);
     });
 
     test('getPushrules', () async {
@@ -352,8 +353,7 @@ void main() {
           lang: "en",
           data: PusherData(
               format: "event_id_only", url: "https://examplepushserver.com"));
-      final dynamic resp = await matrix.setPushers(data);
-      expect(resp is ErrorResponse, false);
+      await matrix.setPushers(data);
     });
 
     test('joinRoomById', () async {
@@ -389,8 +389,13 @@ void main() {
     test('Logout when token is unknown', () async {
       Future<LoginState> loginStateFuture =
           matrix.connection.onLoginStateChanged.stream.first;
-      await matrix.connection
-          .jsonRequest(type: HTTPType.DELETE, action: "/unknown/token");
+
+      try {
+        await matrix.connection
+            .jsonRequest(type: HTTPType.DELETE, action: "/unknown/token");
+      } on MatrixException catch (exception) {
+        expect(exception.error, MatrixError.M_UNKNOWN_TOKEN);
+      }
 
       LoginState state = await loginStateFuture;
       expect(state, LoginState.loggedOut);
diff --git a/test/FakeMatrixApi.dart b/test/FakeMatrixApi.dart
index 745c0e6b..5c4f471e 100644
--- a/test/FakeMatrixApi.dart
+++ b/test/FakeMatrixApi.dart
@@ -48,12 +48,17 @@ class FakeMatrixApi extends MockClient {
 
           if (request.url.origin != "https://fakeserver.notexisting")
             return Response(
-                "<html><head></head><body>Not found...</body></html>", 50);
+                "<html><head></head><body>Not found...</body></html>", 404);
 
           // Call API
           if (api.containsKey(method) && api[method].containsKey(action))
             res = api[method][action](data);
-          else
+          else if (method == "GET" &&
+              action.contains("/client/r0/rooms/") &&
+              action.contains("/state/m.room.member/")) {
+            res = {"displayname": ""};
+            return Response(json.encode(res), 200);
+          } else
             res = {
               "errcode": "M_UNRECOGNIZED",
               "error": "Unrecognized request"
@@ -62,6 +67,64 @@ class FakeMatrixApi extends MockClient {
           return Response(json.encode(res), 100);
         });
 
+  static Map<String, dynamic> messagesResponse = {
+    "start": "t47429-4392820_219380_26003_2265",
+    "end": "t47409-4357353_219380_26003_2265",
+    "chunk": [
+      {
+        "content": {
+          "body": "This is an example text message",
+          "msgtype": "m.text",
+          "format": "org.matrix.custom.html",
+          "formatted_body": "<b>This is an example text message</b>"
+        },
+        "type": "m.room.message",
+        "event_id": "3143273582443PhrSn:example.org",
+        "room_id": "!1234:example.com",
+        "sender": "@example:example.org",
+        "origin_server_ts": 1432735824653,
+        "unsigned": {"age": 1234}
+      },
+      {
+        "content": {"name": "The room name"},
+        "type": "m.room.name",
+        "event_id": "2143273582443PhrSn:example.org",
+        "room_id": "!1234:example.com",
+        "sender": "@example:example.org",
+        "origin_server_ts": 1432735824653,
+        "unsigned": {"age": 1234},
+        "state_key": ""
+      },
+      {
+        "content": {
+          "body": "Gangnam Style",
+          "url": "mxc://example.org/a526eYUSFFxlgbQYZmo442",
+          "info": {
+            "thumbnail_url": "mxc://example.org/FHyPlCeYUSFFxlgbQYZmoEoe",
+            "thumbnail_info": {
+              "mimetype": "image/jpeg",
+              "size": 46144,
+              "w": 300,
+              "h": 300
+            },
+            "w": 480,
+            "h": 320,
+            "duration": 2140786,
+            "size": 1563685,
+            "mimetype": "video/mp4"
+          },
+          "msgtype": "m.video"
+        },
+        "type": "m.room.message",
+        "event_id": "1143273582443PhrSn:example.org",
+        "room_id": "!1234:example.com",
+        "sender": "@example:example.org",
+        "origin_server_ts": 1432735824653,
+        "unsigned": {"age": 1234}
+      }
+    ]
+  };
+
   static Map<String, dynamic> syncResponse = {
     "next_batch": Random().nextDouble().toString(),
     "presence": {
@@ -457,6 +520,8 @@ class FakeMatrixApi extends MockClient {
 
   static final Map<String, Map<String, dynamic>> api = {
     "GET": {
+      "/client/r0/rooms/1/state/m.room.member/@alice:example.com": (var req) =>
+          {"displayname": "Alice"},
       "/client/r0/profile/@getme:example.com": (var req) => {
             "avatar_url": "mxc://test",
             "displayname": "You got me",
@@ -480,65 +545,10 @@ class FakeMatrixApi extends MockClient {
             "origin_server_ts": 1432735824653,
             "unsigned": {"age": 1234}
           },
+      "/client/r0/rooms/!localpart:server.abc/messages?from=&dir=b&limit=100&filter=%7B%22room%22:%7B%22state%22:%7B%22lazy_load_members%22:true%7D%7D%7D":
+          (var req) => messagesResponse,
       "/client/r0/rooms/!1234:example.com/messages?from=1234&dir=b&limit=100&filter=%7B%22room%22:%7B%22state%22:%7B%22lazy_load_members%22:true%7D%7D%7D":
-          (var req) => {
-                "start": "t47429-4392820_219380_26003_2265",
-                "end": "t47409-4357353_219380_26003_2265",
-                "chunk": [
-                  {
-                    "content": {
-                      "body": "This is an example text message",
-                      "msgtype": "m.text",
-                      "format": "org.matrix.custom.html",
-                      "formatted_body": "<b>This is an example text message</b>"
-                    },
-                    "type": "m.room.message",
-                    "event_id": "3143273582443PhrSn:example.org",
-                    "room_id": "!1234:example.com",
-                    "sender": "@example:example.org",
-                    "origin_server_ts": 1432735824653,
-                    "unsigned": {"age": 1234}
-                  },
-                  {
-                    "content": {"name": "The room name"},
-                    "type": "m.room.name",
-                    "event_id": "2143273582443PhrSn:example.org",
-                    "room_id": "!1234:example.com",
-                    "sender": "@example:example.org",
-                    "origin_server_ts": 1432735824653,
-                    "unsigned": {"age": 1234},
-                    "state_key": ""
-                  },
-                  {
-                    "content": {
-                      "body": "Gangnam Style",
-                      "url": "mxc://example.org/a526eYUSFFxlgbQYZmo442",
-                      "info": {
-                        "thumbnail_url":
-                            "mxc://example.org/FHyPlCeYUSFFxlgbQYZmoEoe",
-                        "thumbnail_info": {
-                          "mimetype": "image/jpeg",
-                          "size": 46144,
-                          "w": 300,
-                          "h": 300
-                        },
-                        "w": 480,
-                        "h": 320,
-                        "duration": 2140786,
-                        "size": 1563685,
-                        "mimetype": "video/mp4"
-                      },
-                      "msgtype": "m.video"
-                    },
-                    "type": "m.room.message",
-                    "event_id": "1143273582443PhrSn:example.org",
-                    "room_id": "!1234:example.com",
-                    "sender": "@example:example.org",
-                    "origin_server_ts": 1432735824653,
-                    "unsigned": {"age": 1234}
-                  }
-                ]
-              },
+          (var req) => messagesResponse,
       "/client/versions": (var req) => {
             "versions": [
               "r0.0.1",
diff --git a/test/RoomList_test.dart b/test/RoomList_test.dart
index baa96953..dd30a4b2 100644
--- a/test/RoomList_test.dart
+++ b/test/RoomList_test.dart
@@ -29,14 +29,17 @@ import 'package:famedlysdk/src/sync/RoomUpdate.dart';
 import 'package:famedlysdk/src/utils/ChatTime.dart';
 import 'package:test/test.dart';
 
+import 'FakeMatrixApi.dart';
+
 void main() {
   /// All Tests related to the MxContent
   group("RoomList", () {
     final roomID = "!1:example.com";
 
     test("Create and insert one room", () async {
-      final Client client = Client("testclient");
-      client.homeserver = "https://testserver.abc";
+      final Client client = Client("testclient", debug: true);
+      client.connection.httpClient = FakeMatrixApi();
+      await client.checkServer("https://fakeserver.notexisting");
       client.prevBatch = "1234";
 
       int updateCount = 0;
@@ -84,8 +87,9 @@ void main() {
     });
 
     test("Restort", () async {
-      final Client client = Client("testclient");
-      client.homeserver = "https://testserver.abc";
+      final Client client = Client("testclient", debug: true);
+      client.connection.httpClient = FakeMatrixApi();
+      await client.checkServer("https://fakeserver.notexisting");
       client.prevBatch = "1234";
 
       int updateCount = 0;
@@ -186,7 +190,7 @@ void main() {
       await new Future.delayed(new Duration(milliseconds: 50));
 
       expect(updateCount, 5);
-      expect(roomUpdates, 2);
+      expect(roomUpdates, 3);
       expect(insertList, [0, 1]);
       expect(removeList, []);
 
@@ -224,8 +228,9 @@ void main() {
     });
 
     test("onlyLeft", () async {
-      final Client client = Client("testclient");
-      client.homeserver = "https://testserver.abc";
+      final Client client = Client("testclient", debug: true);
+      client.connection.httpClient = FakeMatrixApi();
+      await client.checkServer("https://fakeserver.notexisting");
       client.prevBatch = "1234";
 
       int updateCount = 0;
@@ -268,9 +273,9 @@ void main() {
       expect(roomList.eventSub != null, true);
       expect(roomList.roomSub != null, true);
       expect(roomList.rooms[0].id, "2");
-      expect(updateCount, 2);
       expect(insertList, [0]);
       expect(removeList, []);
+      expect(updateCount, 2);
     });
   });
 }
diff --git a/test/Room_test.dart b/test/Room_test.dart
index d37dc390..3ceaca84 100644
--- a/test/Room_test.dart
+++ b/test/Room_test.dart
@@ -145,9 +145,7 @@ void main() {
     });
 
     test("sendReadReceipt", () async {
-      final dynamic resp =
-          await room.sendReadReceipt("§1234:fakeServer.notExisting");
-      expect(resp, {});
+      await room.sendReadReceipt("§1234:fakeServer.notExisting");
     });
 
     test("requestParticipants", () async {
@@ -167,28 +165,25 @@ void main() {
     });
 
     test("setName", () async {
-      final dynamic resp = await room.setName("Testname");
-      expect(resp["event_id"], "42");
+      final String eventId = await room.setName("Testname");
+      expect(eventId, "42");
     });
 
     test("setDescription", () async {
-      final dynamic resp = await room.setDescription("Testname");
-      expect(resp["event_id"], "42");
+      final String eventId = await room.setDescription("Testname");
+      expect(eventId, "42");
     });
 
     test("kick", () async {
-      final dynamic resp = await room.kick("Testname");
-      expect(resp, {});
+      await room.kick("Testname");
     });
 
     test("ban", () async {
-      final dynamic resp = await room.ban("Testname");
-      expect(resp, {});
+      await room.ban("Testname");
     });
 
     test("unban", () async {
-      final dynamic resp = await room.unban("Testname");
-      expect(resp, {});
+      await room.unban("Testname");
     });
 
     test("PowerLevels", () async {
@@ -259,18 +254,17 @@ void main() {
       expect(room.canSendEvent("m.room.power_levels"), false);
       expect(room.canSendEvent("m.room.member"), false);
       expect(room.canSendEvent("m.room.message"), true);
-      final dynamic resp =
+      final String resp =
           await room.setPower("@test:fakeServer.notExisting", 90);
-      expect(resp["event_id"], "42");
+      expect(resp, "42");
     });
 
     test("invite", () async {
-      final dynamic resp = await room.invite("Testname");
-      expect(resp, {});
+      await room.invite("Testname");
     });
 
     test("getParticipants", () async {
-      room.states["@alice:test.abc"] = RoomState(
+      room.setState(RoomState(
           senderId: "@alice:test.abc",
           typeKey: "m.room.member",
           roomId: room.id,
@@ -278,15 +272,14 @@ void main() {
           eventId: "12345",
           time: ChatTime.now(),
           content: {"displayname": "alice"},
-          stateKey: "@alice:test.abc");
+          stateKey: "@alice:test.abc"));
       final List<User> userList = room.getParticipants();
-      expect(userList.length, 1);
-      expect(userList[0].displayName, "alice");
+      expect(userList.length, 4);
+      expect(userList[3].displayName, "alice");
     });
 
     test("addToDirectChat", () async {
-      final dynamic resp = await room.addToDirectChat("Testname");
-      expect(resp, {});
+      await room.addToDirectChat("Testname");
     });
 
     test("getTimeline", () async {
@@ -295,7 +288,10 @@ void main() {
     });
 
     test("getUserByMXID", () async {
-      final User user = await room.getUserByMXID("@getme:example.com");
+      User user;
+      try {
+        user = await room.getUserByMXID("@getme:example.com");
+      } catch (_) {}
       expect(user.stateKey, "@getme:example.com");
       expect(user.calcDisplayname(), "You got me");
     });