From ea0e3de4302a9602e710e0ca14396e9e5a4eb3e4 Mon Sep 17 00:00:00 2001
From: "N. Taylor Mullen" <ntaylormullen@google.com>
Date: Mon, 19 Jan 2026 20:29:45 -0800
Subject: [PATCH] fix(core): deduplicate ModelInfo emission in GeminiClient
 (#17075)

---
 packages/core/src/core/client.test.ts | 11 +++++------
 packages/core/src/core/client.ts      |  5 +++--
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/packages/core/src/core/client.test.ts b/packages/core/src/core/client.test.ts
index 50ee7f765a..1c86d5175d 100644
--- a/packages/core/src/core/client.test.ts
+++ b/packages/core/src/core/client.test.ts
@@ -1649,7 +1649,6 @@ ${JSON.stringify(
       expect(events).toEqual([
         { type: GeminiEventType.ModelInfo, value: 'default-routed-model' },
         { type: GeminiEventType.InvalidStream },
-        { type: GeminiEventType.ModelInfo, value: 'default-routed-model' },
         { type: GeminiEventType.Content, value: 'Continued content' },
       ]);
 
@@ -1737,13 +1736,13 @@ ${JSON.stringify(
       const events = await fromAsync(stream);
 
       // Assert
-      // We expect 4 events (model_info + original + model_info + 1 retry)
-      expect(events.length).toBe(4);
+      // We expect 3 events (model_info + original + 1 retry)
+      expect(events.length).toBe(3);
       expect(
         events
-          .filter((e) => e.type !== GeminiEventType.ModelInfo)
-          .every((e) => e.type === GeminiEventType.InvalidStream),
-      ).toBe(true);
+          .filter((e) => e.type === GeminiEventType.ModelInfo)
+          .map((e) => e.value),
+      ).toEqual(['default-routed-model']);
 
       // Verify that turn.run was called twice
       expect(mockTurnRunFn).toHaveBeenCalledTimes(2);
diff --git a/packages/core/src/core/client.ts b/packages/core/src/core/client.ts
index dbf81aee2f..165aa7c00f 100644
--- a/packages/core/src/core/client.ts
+++ b/packages/core/src/core/client.ts
@@ -626,9 +626,10 @@ export class GeminiClient {
     );
     modelToUse = finalModel;
 
+    if (!signal.aborted && !this.currentSequenceModel) {
+      yield { type: GeminiEventType.ModelInfo, value: modelToUse };
+    }
     this.currentSequenceModel = modelToUse;
-    yield { type: GeminiEventType.ModelInfo, value: modelToUse };
-
     const resultStream = turn.run(modelConfigKey, request, linkedSignal);
     let isError = false;
     let isInvalidStream = false;