From 5d0841899b1332a1451d9ff26a65f88711ccc269 Mon Sep 17 00:00:00 2001
From: kangfenmao <kangfenmao@qq.com>
Date: Tue, 18 Nov 2025 13:52:57 +0800
Subject: [PATCH] fix(conversation): set context length to 1 for
 gemini-2.5-flash-image model

Set context count to 1 for gemini-2.5-flash-image (Nano Banana) model to fix continuous conversation failures. This ensures the model only receives the most recent message, preventing context-related errors.

Changes:
- Add isGeminiGenerateImageModel utility to identify Nano Banana models
- Override contextCount to 1 when using gemini-2.5-flash-image
- Remove the previous +2 offset from contextCount calculation
---
 src/renderer/src/aiCore/utils/image.ts           |  4 ++++
 src/renderer/src/services/ConversationService.ts | 12 ++++++++++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/renderer/src/aiCore/utils/image.ts b/src/renderer/src/aiCore/utils/image.ts
index 37dbe76a2c..a2a755e87f 100644
--- a/src/renderer/src/aiCore/utils/image.ts
+++ b/src/renderer/src/aiCore/utils/image.ts
@@ -14,3 +14,7 @@ export function isOpenRouterGeminiGenerateImageModel(model: Model, provider: Pro
     provider.id === SystemProviderIds.openrouter
   )
 }
+
+export function isGeminiGenerateImageModel(model: Model): boolean {
+  return model.id.includes('gemini-2.5-flash-image')
+}
diff --git a/src/renderer/src/services/ConversationService.ts b/src/renderer/src/services/ConversationService.ts
index f9e3f4dea5..576dd99c3a 100644
--- a/src/renderer/src/services/ConversationService.ts
+++ b/src/renderer/src/services/ConversationService.ts
@@ -1,4 +1,5 @@
 import { convertMessagesToSdkMessages } from '@renderer/aiCore/prepareParams'
+import { isGeminiGenerateImageModel } from '@renderer/aiCore/utils/image'
 import type { Assistant, Message } from '@renderer/types'
 import { filterAdjacentUserMessaegs, filterLastAssistantMessage } from '@renderer/utils/messageUtils/filters'
 import type { ModelMessage } from 'ai'
@@ -17,7 +18,14 @@ export class ConversationService {
     messages: Message[],
     assistant: Assistant
   ): Promise<{ modelMessages: ModelMessage[]; uiMessages: Message[] }> {
-    const { contextCount } = getAssistantSettings(assistant)
+    let { contextCount } = getAssistantSettings(assistant)
+
+    contextCount = contextCount + 2
+
+    if (assistant.model && isGeminiGenerateImageModel(assistant.model)) {
+      contextCount = 1
+    }
+
     // This logic is extracted from the original ApiService.fetchChatCompletion
     // const contextMessages = filterContextMessages(messages)
     const lastUserMessage = findLast(messages, (m) => m.role === 'user')
@@ -37,7 +45,7 @@ export class ConversationService {
     const filteredMessages4 = filterAdjacentUserMessaegs(filteredMessages3)
 
     let uiMessages = filterUserRoleStartMessages(
-      filterEmptyMessages(filterAfterContextClearMessages(takeRight(filteredMessages4, contextCount + 2))) // 取原来几个provider的最大值
+      filterEmptyMessages(filterAfterContextClearMessages(takeRight(filteredMessages4, contextCount))) // 取原来几个provider的最大值
     )
 
     // Fallback: ensure at least the last user message is present to avoid empty payloads