From 6740886e22827f04ef52141f1ed049420dc915cc Mon Sep 17 00:00:00 2001
From: Sehoon Shon <sshon@google.com>
Date: Thu, 15 Jan 2026 12:26:54 -0500
Subject: [PATCH] fix(core): prevent ModelInfo event emission on aborted signal
 (#16752)

---
 packages/core/src/core/client.test.ts | 28 +++++++++++++++++++++++++++
 packages/core/src/core/client.ts      |  5 +++--
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/packages/core/src/core/client.test.ts b/packages/core/src/core/client.test.ts
index 50ee7f765a..11dc28a998 100644
--- a/packages/core/src/core/client.test.ts
+++ b/packages/core/src/core/client.test.ts
@@ -679,6 +679,34 @@ describe('Gemini Client (client.ts)', () => {
       });
     });
 
+    it('does not emit ModelInfo event if signal is aborted', async () => {
+      // Arrange
+      mockTurnRunFn.mockReturnValue(
+        (async function* () {
+          yield { type: 'content', value: 'Hello' };
+        })(),
+      );
+
+      const controller = new AbortController();
+      controller.abort();
+
+      // Act
+      const stream = client.sendMessageStream(
+        [{ text: 'Hi' }],
+        controller.signal,
+        'prompt-id-1',
+      );
+
+      const events = await fromAsync(stream);
+
+      // Assert
+      expect(events).not.toContainEqual(
+        expect.objectContaining({
+          type: GeminiEventType.ModelInfo,
+        }),
+      );
+    });
+
     it.each([
       {
         compressionStatus:
diff --git a/packages/core/src/core/client.ts b/packages/core/src/core/client.ts
index dbf81aee2f..73445da67b 100644
--- a/packages/core/src/core/client.ts
+++ b/packages/core/src/core/client.ts
@@ -627,8 +627,9 @@ export class GeminiClient {
     modelToUse = finalModel;
 
     this.currentSequenceModel = modelToUse;
-    yield { type: GeminiEventType.ModelInfo, value: modelToUse };
-
+    if (!signal.aborted) {
+      yield { type: GeminiEventType.ModelInfo, value: modelToUse };
+    }
     const resultStream = turn.run(modelConfigKey, request, linkedSignal);
     let isError = false;
     let isInvalidStream = false;