fix(local-mcp): don't submit before local MCP servers finish loading

useTaskCreation read useLocalMcpCloudServers's data at submit time without
checking it had resolved. Submitting a cloud task before the (async,
~/.claude.json-backed) query settled silently shipped importedMcpServers and
relayedMcpServers empty, dropping the user's local servers with no error.

useLocalMcpCloudServers now returns { servers, isLoading } instead of a bare
array; isLoading tracks the query's own isLoading (false while disabled, so
it never blocks a caller that isn't waiting on it). useTaskCreation blocks
submit with a toast while loading; McpServersView takes the servers field
unchanged.

Author: richardsolomou

packages/ui/src/features/local-mcp/useLocalMcpCloudServers.ts

@@ -9,14 +9,21 @@ import { useQuery } from "@tanstack/react-query";
 // Stable identity so consumers' memo deps don't churn while data is absent.
 const NO_SERVERS: LocalMcpCloudClassification[] = [];
 
+export interface LocalMcpCloudServersResult {
+  servers: LocalMcpCloudClassification[];
+  /** True only during the initial fetch while enabled — false once resolved,
+   *  and false while disabled, so a disabled query never blocks a caller. */
+  isLoading: boolean;
+}
+
 /**
  * The user's local (~/.claude.json) MCP servers classified by cloud
  * availability. Empty on hosts without a local workspace (web/mobile — the
  * service is only bound on desktop).
  */
 export function useLocalMcpCloudServers(
   enabled: boolean,
-): LocalMcpCloudClassification[] {
+): LocalMcpCloudServersResult {
   const service = useServiceOptional<LocalMcpImportService>(
     LOCAL_MCP_IMPORT_SERVICE,
   );
@@ -28,5 +35,5 @@ export function useLocalMcpCloudServers(
     staleTime: 30_000,
   });
 
-  return query.data ?? NO_SERVERS;
+  return { servers: query.data ?? NO_SERVERS, isLoading: query.isLoading };
 }

packages/ui/src/features/mcp-servers/components/McpServersView.tsx

@@ -77,7 +77,7 @@ export function McpServersView() {
     reauthorizePending,
   } = useMcpServers();
 
-  const localServers = useLocalMcpCloudServers(true);
+  const { servers: localServers } = useLocalMcpCloudServers(true);
 
   useEffect(() => {
     const refreshMcpState = () => {

packages/ui/src/features/task-detail/hooks/useTaskCreation.ts

@@ -195,7 +195,8 @@ export function useTaskCreation({
     additionalDirectoriesOverride ?? defaultAdditionalDirectories;
   // Importable local MCP servers for cloud runs, self-fetched like the
   // additional-directory defaults above rather than threaded in by callers.
-  const localMcpServers = useLocalMcpCloudServers(workspaceMode === "cloud");
+  const { servers: localMcpServers, isLoading: localMcpServersLoading } =
+    useLocalMcpCloudServers(workspaceMode === "cloud");
   const taskService = useService<TaskService>(TASK_SERVICE);
   const clearTaskInputReportAssociation = useTaskInputPrefillStore(
     (s) => s.clearReportAssociation,
@@ -240,6 +241,16 @@ export function useTaskCreation({
         return false;
       }
 
+      // The local MCP server classification is fetched lazily on entering cloud
+      // mode; submitting before it resolves would silently drop importedMcpServers/
+      // relayedMcpServers below instead of including the user's local servers.
+      if (workspaceMode === "cloud" && localMcpServersLoading) {
+        toast.error("Still checking your local MCP servers", {
+          description: "Try again in a moment.",
+        });
+        return false;
+      }
+
       // Confirm a couple of worktree branch situations before starting the
       // task. Done before the pending view so a dialog (and a cancel) don't
       // leave a half-started task on screen. Reusing an existing worktree takes
@@ -534,6 +545,7 @@ export function useTaskCreation({
       bluebirdEnabled,
       personalChannel?.id,
       localMcpServers,
+      localMcpServersLoading,
       clearTaskInputReportAssociation,
       invalidateTasks,
       onTaskCreated,