diff --git a/apps/ios/Shared/Model/SimpleXAPI.swift b/apps/ios/Shared/Model/SimpleXAPI.swift
index fff1d6d497..3fa219128b 100644
--- a/apps/ios/Shared/Model/SimpleXAPI.swift
+++ b/apps/ios/Shared/Model/SimpleXAPI.swift
@@ -217,7 +217,7 @@ func apiDeleteUser(_ userId: Int64, _ delSMPQueues: Bool, viewPwd: String?) asyn
 }
 
 func apiStartChat(ctrl: chat_ctrl? = nil) throws -> Bool {
-    let r = chatSendCmdSync(.startChat(mainApp: true), ctrl)
+    let r = chatSendCmdSync(.startChat(mainApp: true, enableSndFiles: true), ctrl)
     switch r {
     case .chatStarted: return true
     case .chatRunning: return false
diff --git a/apps/ios/SimpleX NSE/NotificationService.swift b/apps/ios/SimpleX NSE/NotificationService.swift
index 764415b1aa..3850664429 100644
--- a/apps/ios/SimpleX NSE/NotificationService.swift	
+++ b/apps/ios/SimpleX NSE/NotificationService.swift	
@@ -636,7 +636,7 @@ func apiGetActiveUser() -> User? {
 }
 
 func apiStartChat() throws -> Bool {
-    let r = sendSimpleXCmd(.startChat(mainApp: false))
+    let r = sendSimpleXCmd(.startChat(mainApp: false, enableSndFiles: false))
     switch r {
     case .chatStarted: return true
     case .chatRunning: return false
diff --git a/apps/ios/SimpleXChat/APITypes.swift b/apps/ios/SimpleXChat/APITypes.swift
index 4478aa5b62..2da068653d 100644
--- a/apps/ios/SimpleXChat/APITypes.swift
+++ b/apps/ios/SimpleXChat/APITypes.swift
@@ -26,7 +26,7 @@ public enum ChatCommand {
     case apiMuteUser(userId: Int64)
     case apiUnmuteUser(userId: Int64)
     case apiDeleteUser(userId: Int64, delSMPQueues: Bool, viewPwd: String?)
-    case startChat(mainApp: Bool)
+    case startChat(mainApp: Bool, enableSndFiles: Bool)
     case apiStopChat
     case apiActivateChat(restoreChat: Bool)
     case apiSuspendChat(timeoutMicroseconds: Int)
@@ -171,7 +171,7 @@ public enum ChatCommand {
             case let .apiMuteUser(userId): return "/_mute user \(userId)"
             case let .apiUnmuteUser(userId): return "/_unmute user \(userId)"
             case let .apiDeleteUser(userId, delSMPQueues, viewPwd): return "/_delete user \(userId) del_smp=\(onOff(delSMPQueues))\(maybePwd(viewPwd))"
-            case let .startChat(mainApp): return "/_start main=\(onOff(mainApp))"
+            case let .startChat(mainApp, enableSndFiles): return "/_start main=\(onOff(mainApp)) snd_files=\(enableSndFiles)"
             case .apiStopChat: return "/_stop"
             case let .apiActivateChat(restore): return "/_app activate restore=\(onOff(restore))"
             case let .apiSuspendChat(timeoutMicroseconds): return "/_app suspend \(timeoutMicroseconds)"
diff --git a/cabal.project b/cabal.project
index e7e30afb3c..3573976290 100644
--- a/cabal.project
+++ b/cabal.project
@@ -12,7 +12,7 @@ constraints: zip +disable-bzip2 +disable-zstd
 source-repository-package
     type: git
     location: https://github.com/simplex-chat/simplexmq.git
-    tag: b40d55c358ebabeb6cf1eca8e64016e2bae09a15
+    tag: 8d56b0ba8519bdc68a3777d8d0672fbe01957479
 
 source-repository-package
     type: git
diff --git a/scripts/nix/sha256map.nix b/scripts/nix/sha256map.nix
index 6eaf36e709..9f1dd6d69c 100644
--- a/scripts/nix/sha256map.nix
+++ b/scripts/nix/sha256map.nix
@@ -1,5 +1,5 @@
 {
-  "https://github.com/simplex-chat/simplexmq.git"."b40d55c358ebabeb6cf1eca8e64016e2bae09a15" = "1ppn2yvml12yr5k5d6hjn7r7xy6a83ig9mys49jzzk034rzwxcd2";
+  "https://github.com/simplex-chat/simplexmq.git"."8d56b0ba8519bdc68a3777d8d0672fbe01957479" = "1yfcgnkhal6kj26kcl805152b1gai2ncyfq9lyq5k8jvdh0hpq99";
   "https://github.com/simplex-chat/hs-socks.git"."a30cc7a79a08d8108316094f8f2f82a0c5e1ac51" = "0yasvnr7g91k76mjkamvzab2kvlb1g5pspjyjn2fr6v83swjhj38";
   "https://github.com/simplex-chat/direct-sqlcipher.git"."f814ee68b16a9447fbb467ccc8f29bdd3546bfd9" = "1ql13f4kfwkbaq7nygkxgw84213i0zm7c1a8hwvramayxl38dq5d";
   "https://github.com/simplex-chat/sqlcipher-simple.git"."a46bd361a19376c5211f1058908fc0ae6bf42446" = "1z0r78d8f0812kxbgsm735qf6xx8lvaz27k1a0b4a2m0sshpd5gl";
diff --git a/src/Simplex/Chat.hs b/src/Simplex/Chat.hs
index d31c2cdeca..46c8f97d53 100644
--- a/src/Simplex/Chat.hs
+++ b/src/Simplex/Chat.hs
@@ -384,8 +384,9 @@ cfgServers p DefaultAgentServers {smp, xftp} = case p of
   SPSMP -> smp
   SPXFTP -> xftp
 
-startChatController :: Bool -> CM' (Async ())
-startChatController mainApp = do
+-- enableSndFiles has no effect when mainApp is True
+startChatController :: Bool -> Bool -> CM' (Async ())
+startChatController mainApp enableSndFiles = do
   asks smpAgent >>= liftIO . resumeAgentClient
   unless mainApp $ chatWriteVar' subscriptionMode SMOnlyCreate
   users <- fromRight [] <$> runExceptT (withStore' getUsers)
@@ -400,15 +401,18 @@ startChatController mainApp = do
           then Just <$> async (subscribeUsers False users)
           else pure Nothing
       atomically . writeTVar s $ Just (a1, a2)
-      when mainApp $ do
-        startXFTP
-        void $ forkIO $ startFilesToReceive users
-        startCleanupManager
-        startExpireCIs users
+      if mainApp
+        then do
+          startXFTP xftpStartWorkers
+          void $ forkIO $ startFilesToReceive users
+          startCleanupManager
+          startExpireCIs users
+        else
+          when enableSndFiles $ startXFTP xftpStartSndWorkers
       pure a1
-    startXFTP = do
+    startXFTP startWorkers = do
       tmp <- readTVarIO =<< asks tempDirectory
-      runExceptT (withAgent $ \a -> xftpStartWorkers a tmp) >>= \case
+      runExceptT (withAgent $ \a -> startWorkers a tmp) >>= \case
         Left e -> liftIO $ print $ "Error starting XFTP workers: " <> show e
         Right _ -> pure ()
     startCleanupManager = do
@@ -617,10 +621,10 @@ processChatCommand' vr = \case
     checkDeleteChatUser user'
     withChatLock "deleteUser" . procCmd $ deleteChatUser user' delSMPQueues
   DeleteUser uName delSMPQueues viewPwd_ -> withUserName uName $ \userId -> APIDeleteUser userId delSMPQueues viewPwd_
-  StartChat mainApp -> withUser' $ \_ ->
+  StartChat {mainApp, enableSndFiles} -> withUser' $ \_ ->
     asks agentAsync >>= readTVarIO >>= \case
       Just _ -> pure CRChatRunning
-      _ -> checkStoreNotChanged . lift $ startChatController mainApp $> CRChatStarted
+      _ -> checkStoreNotChanged . lift $ startChatController mainApp enableSndFiles $> CRChatStarted
   APIStopChat -> do
     ask >>= liftIO . stopChatController
     pure CRChatStopped
@@ -7355,8 +7359,11 @@ chatCommandP =
       "/_delete user " *> (APIDeleteUser <$> A.decimal <* " del_smp=" <*> onOffP <*> optional (A.space *> jsonP)),
       "/delete user " *> (DeleteUser <$> displayName <*> pure True <*> optional (A.space *> pwdP)),
       ("/user" <|> "/u") $> ShowActiveUser,
-      "/_start main=" *> (StartChat <$> onOffP),
-      "/_start" $> StartChat True,
+      "/_start " *> do
+        mainApp <- "main=" *> onOffP
+        enableSndFiles <- " snd_files=" *> onOffP <|> pure mainApp
+        pure StartChat {mainApp, enableSndFiles},
+      "/_start" $> StartChat True True,
       "/_stop" $> APIStopChat,
       "/_app activate restore=" *> (APIActivateChat <$> onOffP),
       "/_app activate" $> APIActivateChat True,
diff --git a/src/Simplex/Chat/Controller.hs b/src/Simplex/Chat/Controller.hs
index e08c8a287a..8e2a308986 100644
--- a/src/Simplex/Chat/Controller.hs
+++ b/src/Simplex/Chat/Controller.hs
@@ -263,7 +263,7 @@ data ChatCommand
   | UnmuteUser
   | APIDeleteUser UserId Bool (Maybe UserPwd)
   | DeleteUser UserName Bool (Maybe UserPwd)
-  | StartChat {mainApp :: Bool}
+  | StartChat {mainApp :: Bool, enableSndFiles :: Bool} -- enableSndFiles has no effect when mainApp is True
   | APIStopChat
   | APIActivateChat {restoreChat :: Bool}
   | APISuspendChat {suspendTimeout :: Int}
diff --git a/src/Simplex/Chat/Core.hs b/src/Simplex/Chat/Core.hs
index a8580746d1..07fac82677 100644
--- a/src/Simplex/Chat/Core.hs
+++ b/src/Simplex/Chat/Core.hs
@@ -54,7 +54,7 @@ runSimplexChat :: ChatOpts -> User -> ChatController -> (User -> ChatController
 runSimplexChat ChatOpts {maintenance} u cc chat
   | maintenance = wait =<< async (chat u cc)
   | otherwise = do
-      a1 <- runReaderT (startChatController True) cc
+      a1 <- runReaderT (startChatController True True) cc
       a2 <- async $ chat u cc
       waitEither_ a1 a2