fix: fix/skip interrupt banner for server tools (#353)

Co-authored-by: Letta <noreply@letta.com>

src/cli/App.tsx

@@ -836,6 +836,7 @@ export default function App({
   );
 
   // Core streaming function - iterative loop that processes conversation turns
+  // biome-ignore lint/correctness/useExhaustiveDependencies: refs read .current dynamically
   const processConversation = useCallback(
     async (
       initialInput: Array<MessageCreate | ApprovalCreate>,
@@ -849,6 +850,12 @@ export default function App({
           return;
         }
 
+        // Guard against concurrent processConversation calls
+        // This can happen if user submits two messages in quick succession
+        if (streamingRef.current) {
+          return;
+        }
+
         setStreaming(true);
         abortControllerRef.current = new AbortController();
 
@@ -1532,10 +1539,13 @@ export default function App({
       // Set cancellation flag to prevent processConversation from starting
       userCancelledRef.current = true;
 
-      // Stop streaming and show error message
+      // Stop streaming and show error message (unless tool calls were cancelled,
+      // since the tool result will show "Interrupted by user")
       setStreaming(false);
-      markIncompleteToolsAsCancelled(buffersRef.current);
-      appendError("Stream interrupted by user");
+      const toolsCancelled = markIncompleteToolsAsCancelled(buffersRef.current);
+      if (!toolsCancelled) {
+        appendError("Stream interrupted by user");
+      }
       refreshDerived();
 
       // Clear any pending approvals since we're cancelling

src/cli/helpers/accumulator.ts

@@ -170,11 +170,13 @@ export function markCurrentLineAsFinished(b: Buffers) {
 /**
  * Mark any incomplete tool calls as cancelled when stream is interrupted.
  * This prevents blinking tool calls from staying in progress state.
+ * @returns true if any tool calls were marked as cancelled
  */
-export function markIncompleteToolsAsCancelled(b: Buffers) {
+export function markIncompleteToolsAsCancelled(b: Buffers): boolean {
   // Mark buffer as interrupted to skip stale throttled refreshes
   b.interrupted = true;
 
+  let anyToolsCancelled = false;
   for (const [id, line] of b.byId.entries()) {
     if (line.kind === "tool_call" && line.phase !== "finished") {
       const updatedLine = {
@@ -184,10 +186,12 @@ export function markIncompleteToolsAsCancelled(b: Buffers) {
         resultText: INTERRUPTED_BY_USER,
       };
       b.byId.set(id, updatedLine);
+      anyToolsCancelled = true;
     }
   }
   // Also mark any streaming assistant/reasoning lines as finished
   markCurrentLineAsFinished(b);
+  return anyToolsCancelled;
 }
 
 type ToolCallLine = Extract<Line, { kind: "tool_call" }>;