diff --git a/app/(chat)/api/chat/route.ts b/app/(chat)/api/chat/route.ts
index 3801635a8..3298aa96b 100644
--- a/app/(chat)/api/chat/route.ts
+++ b/app/(chat)/api/chat/route.ts
@@ -3884,6 +3884,16 @@ export async function POST(request: Request) {
       .trim();
     const autoContextText = typeof autoContext === "string" ? autoContext.trim() : "";
 
+    if (composerMode === "agent" && !agentPresetId) {
+      return NextResponse.json(
+        {
+          code: "bad_request:api",
+          message: "智能体模式缺少生图模式配置，请刷新页面后重新选择生图模式再试",
+        },
+        { status: 400 },
+      );
+    }
+
     const now = Date.now();
     for (const [key, startedAt] of inFlightChatRequests.entries()) {
       if (now - startedAt > IN_FLIGHT_REQUEST_TTL_MS) {
diff --git a/components/agents/AgentGenerationWorkspaceDarkV2.tsx b/components/agents/AgentGenerationWorkspaceDarkV2.tsx
index 2cb4892d9..81fea7aca 100644
--- a/components/agents/AgentGenerationWorkspaceDarkV2.tsx
+++ b/components/agents/AgentGenerationWorkspaceDarkV2.tsx
@@ -1081,8 +1081,12 @@ export function AgentGenerationWorkspaceDarkV2({
             hiddenPrompt: hiddenPromptRef.current || undefined,
             agentPresetId:
               transportState.selectedAgentPresetId || selectedAgentPresetId || undefined,
-            selectedChatModel: transportState.selectedModelId,
-            composerMode: "agent" as const,
+            selectedChatModel:
+              transportState.selectedModelId !== "auto"
+                ? transportState.selectedModelId
+                : selectedAgentPreset?.defaultModelId || transportState.selectedModelId,
+            composerMode:
+              selectedAgentPreset?.type === "image" ? ("image" as const) : ("agent" as const),
             selectedVisibilityType: "private",
             imageParams: transportState.imageParams,
             contextPayload: {
diff --git a/components/agents/AgentGenerationWorkspaceNew.tsx b/components/agents/AgentGenerationWorkspaceNew.tsx
index 815595ef3..b9a316c29 100644
--- a/components/agents/AgentGenerationWorkspaceNew.tsx
+++ b/components/agents/AgentGenerationWorkspaceNew.tsx
@@ -365,8 +365,12 @@ export function AgentGenerationWorkspaceNew({
             hiddenPrompt: hiddenPromptRef.current || undefined,
             agentPresetId:
               transportState.selectedAgentPresetId || selectedAgentPresetId || undefined,
-            selectedChatModel: transportState.selectedModelId,
-            composerMode: "agent" as const,
+            selectedChatModel:
+              transportState.selectedModelId !== "auto"
+                ? transportState.selectedModelId
+                : selectedAgentPreset?.defaultModelId || transportState.selectedModelId,
+            composerMode:
+              selectedAgentPreset?.type === "image" ? ("image" as const) : ("agent" as const),
             selectedVisibilityType: "private",
             imageParams: transportState.imageParams,
             contextPayload: {