diff --git a/src/routes/geminiRoutes.js b/src/routes/geminiRoutes.js
index c5d706a3..2a1525f2 100644
--- a/src/routes/geminiRoutes.js
+++ b/src/routes/geminiRoutes.js
@@ -50,7 +50,7 @@ router.post('/messages', authenticateApiKey, async (req, res) => {
     // 提取请求参数
     const {
       messages,
-      model = 'gemini-2.0-flash-exp',
+      model = 'gemini-2.5-flash',
       temperature = 0.7,
       max_tokens = 4096,
       stream = false
@@ -217,7 +217,7 @@ router.get('/models', authenticateApiKey, async (req, res) => {
         object: 'list',
         data: [
           {
-            id: 'gemini-2.0-flash-exp',
+            id: 'gemini-2.5-flash',
             object: 'model',
             created: Date.now() / 1000,
             owned_by: 'google'
@@ -311,8 +311,8 @@ async function handleLoadCodeAssist(req, res) {
   try {
     const sessionHash = sessionHelper.generateSessionHash(req.body)
 
-    // 使用统一调度选择账号（传递请求的模型）
-    const requestedModel = req.body.model
+    // 从路径参数或请求体中获取模型名
+    const requestedModel = req.body.model || req.params.modelName || 'gemini-2.5-flash'
     const { accountId } = await unifiedGeminiScheduler.selectAccountForApiKey(
       req.apiKey,
       sessionHash,
@@ -368,8 +368,8 @@ async function handleOnboardUser(req, res) {
     const { tierId, cloudaicompanionProject, metadata } = req.body
     const sessionHash = sessionHelper.generateSessionHash(req.body)
 
-    // 使用统一调度选择账号（传递请求的模型）
-    const requestedModel = req.body.model
+    // 从路径参数或请求体中获取模型名
+    const requestedModel = req.body.model || req.params.modelName || 'gemini-2.5-flash'
     const { accountId } = await unifiedGeminiScheduler.selectAccountForApiKey(
       req.apiKey,
       sessionHash,
@@ -439,7 +439,9 @@ async function handleCountTokens(req, res) {
   try {
     // 处理请求体结构，支持直接 contents 或 request.contents
     const requestData = req.body.request || req.body
-    const { contents, model = 'gemini-2.0-flash-exp' } = requestData
+    const { contents } = requestData
+    // 从路径参数或请求体中获取模型名
+    const model = requestData.model || req.params.modelName || 'gemini-2.5-flash'
     const sessionHash = sessionHelper.generateSessionHash(req.body)
 
     // 验证必需参数
@@ -487,7 +489,9 @@ async function handleCountTokens(req, res) {
 // 共用的 generateContent 处理函数
 async function handleGenerateContent(req, res) {
   try {
-    const { model, project, user_prompt_id, request: requestData } = req.body
+    const { project, user_prompt_id, request: requestData } = req.body
+    // 从路径参数或请求体中获取模型名
+    const model = req.body.model || req.params.modelName || 'gemini-2.5-flash'
     const sessionHash = sessionHelper.generateSessionHash(req.body)
 
     // 处理不同格式的请求
@@ -582,7 +586,7 @@ async function handleGenerateContent(req, res) {
       }
     }
 
-    res.json(response)
+    res.json(version === 'v1beta' ? response.response : response)
   } catch (error) {
     const version = req.path.includes('v1beta') ? 'v1beta' : 'v1internal'
     // 打印详细的错误信息
@@ -610,7 +614,9 @@ async function handleStreamGenerateContent(req, res) {
   let abortController = null
 
   try {
-    const { model, project, user_prompt_id, request: requestData } = req.body
+    const { project, user_prompt_id, request: requestData } = req.body
+    // 从路径参数或请求体中获取模型名
+    const model = req.body.model || req.params.modelName || 'gemini-2.5-flash'
     const sessionHash = sessionHelper.generateSessionHash(req.body)
 
     // 处理不同格式的请求
@@ -702,8 +708,28 @@ async function handleStreamGenerateContent(req, res) {
     res.setHeader('Connection', 'keep-alive')
     res.setHeader('X-Accel-Buffering', 'no')
 
+    // SSE 解析函数
+    const parseSSELine = (line) => {
+      if (!line.startsWith('data: ')) {
+        return { type: 'other', line, data: null }
+      }
+
+      const jsonStr = line.substring(6).trim()
+
+      if (!jsonStr || jsonStr === '[DONE]') {
+        return { type: 'control', line, data: null, jsonStr }
+      }
+
+      try {
+        const data = JSON.parse(jsonStr)
+        return { type: 'data', line, data, jsonStr }
+      } catch (e) {
+        return { type: 'invalid', line, data: null, jsonStr, error: e }
+      }
+    }
+
     // 处理流式响应并捕获usage数据
-    let buffer = ''
+    let streamBuffer = '' // 统一的流处理缓冲区
     let totalUsage = {
       promptTokenCount: 0,
       candidatesTokenCount: 0,
@@ -715,32 +741,60 @@ async function handleStreamGenerateContent(req, res) {
       try {
         const chunkStr = chunk.toString()
 
-        // 直接转发数据到客户端
-        if (!res.destroyed) {
-          res.write(chunkStr)
+        if (!chunkStr.trim()) {
+          return
         }
 
-        // 同时解析数据以捕获usage信息
-        buffer += chunkStr
-        const lines = buffer.split('\n')
-        buffer = lines.pop() || ''
+        // 使用统一缓冲区处理不完整的行
+        streamBuffer += chunkStr
+        const lines = streamBuffer.split('\n')
+        streamBuffer = lines.pop() || '' // 保留最后一个不完整的行
+
+        const processedLines = []
 
         for (const line of lines) {
-          if (line.startsWith('data: ') && line.length > 6) {
-            try {
-              const jsonStr = line.slice(6)
-              if (jsonStr && jsonStr !== '[DONE]') {
-                const data = JSON.parse(jsonStr)
+          if (!line.trim()) {
+            continue // 跳过空行，不添加到处理队列
+          }
 
-                // 从响应中提取usage数据
-                if (data.response?.usageMetadata) {
-                  totalUsage = data.response.usageMetadata
-                  logger.debug('📊 Captured Gemini usage data:', totalUsage)
-                }
+          // 解析 SSE 行
+          const parsed = parseSSELine(line)
+
+          // 提取 usage 数据（适用于所有版本）
+          if (parsed.type === 'data' && parsed.data.response?.usageMetadata) {
+            totalUsage = parsed.data.response.usageMetadata
+            logger.debug('📊 Captured Gemini usage data:', totalUsage)
+          }
+
+          // 根据版本处理输出
+          if (version === 'v1beta') {
+            if (parsed.type === 'data') {
+              if (parsed.data.response) {
+                // 有 response 字段，只返回 response 的内容
+                processedLines.push(`data: ${JSON.stringify(parsed.data.response)}`)
+              } else {
+                // 没有 response 字段，返回整个数据对象
+                processedLines.push(`data: ${JSON.stringify(parsed.data)}`)
               }
-            } catch (e) {
-              // 忽略解析错误
+            } else if (parsed.type === 'control') {
+              // 控制消息（如 [DONE]）保持原样
+              processedLines.push(line)
             }
+            // 跳过其他类型的行（'other', 'invalid'）
+          }
+        }
+
+        // 发送数据到客户端
+        if (version === 'v1beta') {
+          for (const line of processedLines) {
+            if (!res.destroyed) {
+              res.write(`${line}\n\n`)
+            }
+          }
+        } else {
+          // v1internal 直接转发原始数据
+          if (!res.destroyed) {
+            res.write(chunkStr)
           }
         }
       } catch (error) {