From d1bcb7ce16115628c14ccd37670f3a599f067cac Mon Sep 17 00:00:00 2001
From: Your Name <your.email@example.com>
Date: Sat, 14 Mar 2026 13:00:42 +0800
Subject: [PATCH] fix: use agent default for agent replies

---
 app/(chat)/api/chat/route.ts | 33 +++++++++++++++++++++++++++++++++
 1 file changed, 33 insertions(+)

diff --git a/app/(chat)/api/chat/route.ts b/app/(chat)/api/chat/route.ts
index d59d702fd..c7e04701b 100644
--- a/app/(chat)/api/chat/route.ts
+++ b/app/(chat)/api/chat/route.ts
@@ -66,6 +66,7 @@ import {
   saveMessages,
   updateMessageById,
   updateChatLastContextById,
+  getAgentAiModelWithProvider,
   getAiModelById,
   getEnabledAiModelsWithProvider,
   getSubModelsByParentModelId,
@@ -3034,6 +3035,7 @@ export async function POST(request: Request) {
     let confirmedPromptForConversationState: string | undefined;
     let smartAutoHistoryMessagesFromDb: DBMessage[] = [];
     let preferredAgentModelId: string | undefined;
+    let configuredAgentConversationModelId: string | undefined;
     let pendingGridConfirmation:
       | PendingGridConfirmation
       | null = null;
@@ -3107,6 +3109,8 @@ export async function POST(request: Request) {
           if (isAiModelAgentAuto(selectedModelConfig)) {
             shouldRunAgentConversation = true;
             shouldKeepSelectedModel = false;
+            preferredAgentModelId = selectedModelConfig.id;
+            configuredAgentConversationModelId = selectedModelConfig.id;
             console.log(
               `[Smart Auto Mode] 🧠 Agent-only model detected, force auto routing: ${selectedModelConfig.displayName}`
             );
@@ -3130,6 +3134,21 @@ export async function POST(request: Request) {
       }
     }
 
+    if (shouldRunAgentConversation && !preferredAgentModelId) {
+      const configuredAgentModel = await getAgentAiModelWithProvider().catch((agentModelError) => {
+        console.warn("[Chat API] Failed to load configured agent model:", agentModelError);
+        return null;
+      });
+
+      if (configuredAgentModel?.model?.id) {
+        preferredAgentModelId = configuredAgentModel.model.id;
+        configuredAgentConversationModelId = configuredAgentModel.model.id;
+        console.log(
+          `[Smart Auto Mode] 🧠 Loaded configured agent conversation model: ${configuredAgentModel.model.displayName}`,
+        );
+      }
+    }
+
     const allowAgentVideoGeneration =
       Boolean(requestBody.videoParams) || isVideoProviderType(requestedModelProviderType);
     let smartAutoWorkflowDecision:
@@ -4306,6 +4325,20 @@ export async function POST(request: Request) {
       smartAutoFriendlyMessage = normalizeAgentReportForDisplay(smartAutoFriendlyMessage);
     }
 
+    if (
+      shouldRunAgentConversation &&
+      !shouldKeepSelectedModel &&
+      smartAutoExecution?.shouldStayConversational &&
+      preferredAgentModelId
+    ) {
+      if (finalModelId !== preferredAgentModelId) {
+        finalModelId = preferredAgentModelId;
+        console.log(
+          `[Smart Auto Mode] 🧠 Conversational reply follows agent default model: ${configuredAgentConversationModelId || preferredAgentModelId}`,
+        );
+      }
+    }
+
     const session = await auth();
 
     if (!session?.user) {