From 63ec1392ea50cad808ef92c7024894cd94260bed Mon Sep 17 00:00:00 2001
From: davidapierce <davidapierce@google.com>
Date: Thu, 23 Jul 2026 20:03:19 +0000
Subject: [PATCH] maintain turn metadata and coalesce same roles.

---
 packages/core/src/core/geminiChat.test.ts | 49 +++++++++++++++++++++++
 packages/core/src/core/geminiChat.ts      |  4 +-
 2 files changed, 51 insertions(+), 2 deletions(-)

diff --git a/packages/core/src/core/geminiChat.test.ts b/packages/core/src/core/geminiChat.test.ts
index f9ba444544..83d97e59d9 100644
--- a/packages/core/src/core/geminiChat.test.ts
+++ b/packages/core/src/core/geminiChat.test.ts
@@ -2363,6 +2363,30 @@ describe('GeminiChat', () => {
       expect(turns).toHaveLength(1);
       expect(turns[0].content.role).toBe('user');
     });
+
+    it('should coalesce consecutive user turns when an intermediate model turn is stripped', () => {
+      vi.mocked(mockConfig.isContextManagementEnabled).mockReturnValue(false);
+      vi.mocked(mockConfig.getModel).mockReturnValue('gemini-2.5-pro');
+
+      chat.setHistory([
+        { role: 'user', parts: [{ text: 'Question 1' }] },
+        {
+          role: 'model',
+          parts: [{ text: 'thinking...', thought: true } as unknown as Part],
+        },
+        { role: 'user', parts: [{ text: 'Question 2' }] },
+      ]);
+
+      const turns = chat.getHistoryTurns(true);
+
+      // The model turn contains only a thought part, so it is stripped.
+      // The two adjacent user turns must be coalesced into one user turn.
+      expect(turns).toHaveLength(1);
+      expect(turns[0].content.role).toBe('user');
+      expect(turns[0].content.parts).toHaveLength(2);
+      expect(turns[0].content.parts![0].text).toBe('Question 1');
+      expect(turns[0].content.parts![1].text).toBe('Question 2');
+    });
   });
 
   describe('ensureActiveLoopHasThoughtSignatures', () => {
@@ -3341,5 +3365,30 @@ describe('GeminiChat', () => {
       const history: HistoryTurn[] = [{ id: '1', content: { role: 'user' } }];
       expect(stripThoughts(history)).toEqual(history);
     });
+
+    it('should preserve top-level metadata when stripping thoughts', () => {
+      const history: HistoryTurn[] = [
+        {
+          id: '1',
+          content: {
+            role: 'model',
+            parts: [
+              { text: 'internal monologue', thought: true } as unknown as Part,
+              { text: 'visible response' },
+            ],
+          },
+          // top-level turn metadata
+          timestamp: '2026-07-23T00:00:00.000Z',
+          metadata: { some: 'value' },
+        } as unknown as HistoryTurn,
+      ];
+      const stripped = stripThoughts(history);
+      expect(stripped).toHaveLength(1);
+      expect(stripped[0]).toHaveProperty(
+        'timestamp',
+        '2026-07-23T00:00:00.000Z',
+      );
+      expect(stripped[0]).toHaveProperty('metadata', { some: 'value' });
+    });
   });
 });
diff --git a/packages/core/src/core/geminiChat.ts b/packages/core/src/core/geminiChat.ts
index ab9b40d6e8..e573a69060 100644
--- a/packages/core/src/core/geminiChat.ts
+++ b/packages/core/src/core/geminiChat.ts
@@ -968,7 +968,7 @@ export class GeminiChat {
 
     const model = this.context.config.getModel();
     if (isGemini2Model(model) || supportsModernFeatures(model)) {
-      return stripThoughts(history);
+      return coalesceConsecutiveRoles(stripThoughts(history));
     }
 
     return history;
@@ -1526,7 +1526,7 @@ export function stripThoughts(history: HistoryTurn[]): HistoryTurn[] {
 
       const nonThoughtParts = turn.content.parts.filter((p) => p && !p.thought);
       return {
-        id: turn.id,
+        ...turn,
         content: {
           ...turn.content,
           parts: nonThoughtParts,