From f5205247f7e9b33733e9e467371bb1265dd1890f Mon Sep 17 00:00:00 2001
From: alvinouille <alvinalesaint@protonmail.com>
Date: Tue, 15 Jul 2025 23:20:21 +0200
Subject: [PATCH 1/2] fix: gemini model to gemini-2.5-flash and header when
 streaming:true

---
 .../backend/src/config/provider/gemini.ts     |  2 +-
 .../src/routes/chatCompletionHandler.ts       | 51 +++++++++++++++----
 2 files changed, 41 insertions(+), 12 deletions(-)

diff --git a/packages/backend/src/config/provider/gemini.ts b/packages/backend/src/config/provider/gemini.ts
index c6886caa..61c3a98b 100644
--- a/packages/backend/src/config/provider/gemini.ts
+++ b/packages/backend/src/config/provider/gemini.ts
@@ -17,7 +17,7 @@ export const loadGeminiChatModels = async () => {
       'Gemini Flash 2.5': new ChatGoogleGenerativeAI({
         temperature: 0.7,
         apiKey: geminiApiKey,
-        modelName: 'gemini-2.5-flash-preview-04-17',
+        modelName: 'gemini-2.5-flash',
       }),
     };
 
diff --git a/packages/backend/src/routes/chatCompletionHandler.ts b/packages/backend/src/routes/chatCompletionHandler.ts
index 4bbf87d7..57f567f4 100644
--- a/packages/backend/src/routes/chatCompletionHandler.ts
+++ b/packages/backend/src/routes/chatCompletionHandler.ts
@@ -132,6 +132,11 @@ export async function handleChatCompletion(
       let responseContent = '';
 
       agent.on('data', (data: any) => {
+        // Check if response is already finished
+        if (res.destroyed || res.writableEnded) {
+          return;
+        }
+
         const parsed = JSON.parse(data);
 
         if (parsed.type === 'response') {
@@ -162,14 +167,24 @@ export async function handleChatCompletion(
 
       agent.on('error', (error: any) => {
         console.error('Agent error:', error);
-        res.write(`data: ${JSON.stringify({ error: error.message })}\n\n`);
-        res.end();
+        if (!res.destroyed && !res.writableEnded) {
+          res.write(`data: ${JSON.stringify({ error: error.message })}\n\n`);
+          res.end();
+        }
       });
 
       agent.on('end', () => {
+        // Check if response is already finished
+        if (res.destroyed || res.writableEnded) {
+          return;
+        }
+
         const tokenUsage = TokenTracker.getSessionTokenUsage();
 
-        res.setHeader('x-total-tokens', tokenUsage.totalTokens.toString());
+        // Check if headers haven't been sent yet
+        if (!res.headersSent) {
+          res.setHeader('x-total-tokens', tokenUsage.totalTokens.toString());
+        }
 
         const finalChunk = {
           id: uuidv4(),
@@ -210,16 +225,25 @@ export async function handleChatCompletion(
 
       agent.on('error', (error: any) => {
         console.error('Agent error:', error);
-        res.status(500).json({
-          error: {
-            message: error.message,
-            type: 'server_error',
-            code: 'internal_error',
-          },
-        });
+        
+        // Check if headers haven't been sent yet
+        if (!res.headersSent) {
+          res.status(500).json({
+            error: {
+              message: error.message,
+              type: 'server_error',
+              code: 'internal_error',
+            },
+          });
+        }
       });
 
       agent.on('end', () => {
+        // Check if headers haven't been sent yet
+        if (res.headersSent) {
+          return;
+        }
+
         const tokenUsage = TokenTracker.getSessionTokenUsage();
 
         res.setHeader('x-total-tokens', tokenUsage.totalTokens.toString());
@@ -258,6 +282,11 @@ export async function handleChatCompletion(
   } catch (error) {
     console.error('Error in chat completion:', error);
 
+    // Check if headers haven't been sent yet
+    if (res.headersSent) {
+      return;
+    }
+
     // Map common errors to OpenAI error format
     if (error instanceof Error) {
       const errorResponse: any = {
@@ -292,4 +321,4 @@ export async function handleChatCompletion(
       },
     });
   }
-}
+}
\ No newline at end of file

From e4a9d96fff2421874ec4969df617ce1d4c60659f Mon Sep 17 00:00:00 2001
From: alvinouille <alvinalesaint@protonmail.com>
Date: Tue, 15 Jul 2025 23:26:40 +0200
Subject: [PATCH 2/2] fix: format

---
 packages/backend/src/routes/chatCompletionHandler.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/backend/src/routes/chatCompletionHandler.ts b/packages/backend/src/routes/chatCompletionHandler.ts
index 57f567f4..dc00c3be 100644
--- a/packages/backend/src/routes/chatCompletionHandler.ts
+++ b/packages/backend/src/routes/chatCompletionHandler.ts
@@ -225,7 +225,7 @@ export async function handleChatCompletion(
 
       agent.on('error', (error: any) => {
         console.error('Agent error:', error);
-        
+
         // Check if headers haven't been sent yet
         if (!res.headersSent) {
           res.status(500).json({
@@ -321,4 +321,4 @@ export async function handleChatCompletion(
       },
     });
   }
-}
\ No newline at end of file
+}