diff --git a/README.md b/README.md
index ab5b8da..355a9ae 100644
--- a/README.md
+++ b/README.md
@@ -11,12 +11,13 @@ OpenAI 兼容的 API 代理服务器，统一访问不同的 LLM 模型。
 - **智能优先级** - FACTORY_API_KEY > refresh_token > 客户端authorization
 - **容错启动** - 无任何认证配置时不报错，继续运行支持客户端授权
 
-### 🧠 模型推理能力级别
-- **四档推理级别** - off/low/medium/high，精确控制模型思考深度
+### 🧠 智能推理级别控制
+- **五档推理级别** - auto/off/low/medium/high，灵活控制推理行为
+- **auto模式** - 完全遵循客户端原始请求，不做任何推理参数修改
+- **固定级别** - off/low/medium/high强制覆盖客户端推理设置
 - **OpenAI模型** - 自动注入reasoning字段，effort参数控制推理强度
 - **Anthropic模型** - 自动配置thinking字段和budget_tokens (4096/12288/24576)
-- **智能Beta头管理** - 自动添加/移除anthropic-beta字段中的推理相关标识
-- **配置驱动** - 通过config.json灵活调整每个模型的推理级别
+- **智能头管理** - 根据推理级别自动添加/移除anthropic-beta相关标识
 
 ### 🚀 服务器部署/Docker部署
 - **本地服务器** - 支持npm start快速启动
@@ -103,34 +104,37 @@ export DROID_REFRESH_KEY="your_refresh_token_here"
 
 #### 推理级别配置
 
-每个模型支持四种推理级别：
+每个模型支持五种推理级别：
 
-- **`off`** - 关闭推理功能，使用标准响应
+- **`auto`** - 遵循客户端原始请求，不做任何推理参数修改
+- **`off`** - 强制关闭推理功能，删除所有推理字段
 - **`low`** - 低级推理 (Anthropic: 4096 tokens, OpenAI: low effort)
-- **`medium`** - 中级推理 (Anthropic: 12288 tokens, OpenAI: medium effort)
+- **`medium`** - 中级推理 (Anthropic: 12288 tokens, OpenAI: medium effort) 
 - **`high`** - 高级推理 (Anthropic: 24576 tokens, OpenAI: high effort)
 
 **对于Anthropic模型 (Claude)**：
 ```json
 {
-  "name": "Claude Sonnet 4.5",
+  "name": "Claude Sonnet 4.5", 
   "id": "claude-sonnet-4-5-20250929",
   "type": "anthropic",
-  "reasoning": "high"
+  "reasoning": "auto"  // 推荐：让客户端控制推理
 }
 ```
-自动添加thinking字段和anthropic-beta头，budget_tokens根据级别设置。
+- `auto`: 保留客户端thinking字段，不修改anthropic-beta头
+- `low/medium/high`: 自动添加thinking字段和anthropic-beta头，budget_tokens根据级别设置
 
 **对于OpenAI模型 (GPT)**：
 ```json
 {
-  "name": "GPT-5-Codex",
-  "id": "gpt-5-codex",
-  "type": "openai",
-  "reasoning": "medium"
+  "name": "GPT-5",
+  "id": "gpt-5-2025-08-07",
+  "type": "openai", 
+  "reasoning": "auto"  // 推荐：让客户端控制推理
 }
 ```
-自动添加reasoning字段，effort参数对应配置级别。
+- `auto`: 保留客户端reasoning字段不变
+- `low/medium/high`: 自动添加reasoning字段，effort参数设置为对应级别
 
 ## 使用方法
 
@@ -311,6 +315,36 @@ droid2api完全尊重客户端的stream参数设置：
 - **`"stream": false`** - 禁用流式响应，等待完整结果后返回
 - **不设置stream** - 由服务器端决定默认行为，不强制转换
 
+### 什么是auto推理模式？
+
+`auto` 是v1.3.0新增的推理级别，完全遵循客户端的原始请求：
+
+**行为特点**：
+- 🎯 **零干预** - 不添加、不删除、不修改任何推理相关字段
+- 🔄 **完全透传** - 客户端发什么就转发什么
+- 🛡️ **头信息保护** - 不修改anthropic-beta等推理相关头信息
+
+**使用场景**：
+- 客户端需要完全控制推理参数
+- 与原始API行为保持100%一致
+- 不同客户端有不同的推理需求
+
+**示例对比**：
+```bash
+# 客户端请求包含推理字段
+{
+  "model": "claude-opus-4-1-20250805",
+  "reasoning": "auto",           // 配置为auto
+  "messages": [...],
+  "thinking": {"type": "enabled", "budget_tokens": 8192}
+}
+
+# auto模式：完全保留客户端设置
+→ thinking字段原样转发，不做任何修改
+
+# 如果配置为"high"：会被覆盖为 {"type": "enabled", "budget_tokens": 24576}
+```
+
 ### 如何配置推理级别？
 
 在 `config.json` 中为每个模型设置 `reasoning` 字段：
@@ -319,14 +353,24 @@ droid2api完全尊重客户端的stream参数设置：
 {
   "models": [
     {
-      "id": "claude-opus-4-1-20250805",
+      "id": "claude-opus-4-1-20250805", 
       "type": "anthropic",
-      "reasoning": "high"  // off/low/medium/high
+      "reasoning": "auto"  // auto/off/low/medium/high
     }
   ]
 }
 ```
 
+**推理级别说明**：
+
+| 级别 | 行为 | 适用场景 |
+|------|------|----------|
+| `auto` | 完全遵循客户端原始请求参数 | 让客户端自主控制推理 |
+| `off` | 强制禁用推理，删除所有推理字段 | 快速响应场景 |
+| `low` | 轻度推理 (4096 tokens) | 简单任务 |
+| `medium` | 中度推理 (12288 tokens) | 平衡性能与质量 |
+| `high` | 深度推理 (24576 tokens) | 复杂任务 |
+
 ### 令牌多久刷新一次？
 
 系统每6小时自动刷新一次访问令牌。刷新令牌有效期为8小时，确保有2小时的缓冲时间。
@@ -346,9 +390,19 @@ Token refreshed successfully, expires at: 2025-01-XX XX:XX:XX
 
 ### 推理功能为什么没有生效？
 
-1. 检查模型配置中的 `reasoning` 字段是否设置正确
-2. 确认模型类型匹配（anthropic模型用thinking，openai模型用reasoning）
-3. 查看请求日志确认字段是否正确添加
+**如果推理级别设置无效**：
+1. 检查模型配置中的 `reasoning` 字段是否为有效值 (`auto/off/low/medium/high`)
+2. 确认模型ID是否正确匹配config.json中的配置
+3. 查看服务器日志确认推理字段是否正确处理
+
+**如果使用auto模式但推理不生效**：
+1. 确认客户端请求中包含了推理字段 (`reasoning` 或 `thinking`)
+2. auto模式不会添加推理字段，只会保留客户端原有的设置
+3. 如需强制推理，请改用 `low/medium/high` 级别
+
+**推理字段对应关系**：
+- OpenAI模型 (`gpt-*`) → 使用 `reasoning` 字段
+- Anthropic模型 (`claude-*`) → 使用 `thinking` 字段
 
 ### 如何更改端口？
 
diff --git a/config.js b/config.js
index 44e3085..eaa13a1 100644
--- a/config.js
+++ b/config.js
@@ -56,7 +56,7 @@ export function getModelReasoning(modelId) {
     return null;
   }
   const reasoningLevel = model.reasoning.toLowerCase();
-  if (['low', 'medium', 'high'].includes(reasoningLevel)) {
+  if (['low', 'medium', 'high', 'auto'].includes(reasoningLevel)) {
     return reasoningLevel;
   }
   return null;
diff --git a/config.json b/config.json
index e3e211e..b4bad11 100644
--- a/config.json
+++ b/config.json
@@ -19,25 +19,25 @@
       "name": "Opus 4.1",
       "id": "claude-opus-4-1-20250805",
       "type": "anthropic",
-      "reasoning": "off"
+      "reasoning": "auto"
     },
     {
       "name": "Sonnet 4",
       "id": "claude-sonnet-4-20250514",
       "type": "anthropic",
-      "reasoning": "medium"
+      "reasoning": "auto"
     },
     {
       "name": "Sonnet 4.5",
       "id": "claude-sonnet-4-5-20250929",
       "type": "anthropic",
-      "reasoning": "high"
+      "reasoning": "auto"
     },
     {
       "name": "GPT-5",
       "id": "gpt-5-2025-08-07",
       "type": "openai",
-      "reasoning": "high"
+      "reasoning": "auto"
     },
     {
       "name": "GPT-5-Codex",
diff --git a/package.json b/package.json
index 39db529..d0ca984 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "droid2api",
-  "version": "1.2.2",
+  "version": "1.3.0",
   "description": "OpenAI Compatible API Proxy",
   "main": "server.js",
   "type": "module",
diff --git a/routes.js b/routes.js
index 3d968c1..d8227b9 100644
--- a/routes.js
+++ b/routes.js
@@ -238,7 +238,10 @@ async function handleDirectResponses(req, res) {
 
     // 处理reasoning字段
     const reasoningLevel = getModelReasoning(modelId);
-    if (reasoningLevel) {
+    if (reasoningLevel === 'auto') {
+      // Auto模式：保持原始请求的reasoning字段不变
+      // 如果原始请求有reasoning字段就保留，没有就不添加
+    } else if (reasoningLevel && ['low', 'medium', 'high'].includes(reasoningLevel)) {
       modifiedRequest.reasoning = {
         effort: reasoningLevel,
         summary: 'auto'
@@ -373,7 +376,10 @@ async function handleDirectMessages(req, res) {
 
     // 处理thinking字段
     const reasoningLevel = getModelReasoning(modelId);
-    if (reasoningLevel) {
+    if (reasoningLevel === 'auto') {
+      // Auto模式：保持原始请求的thinking字段不变
+      // 如果原始请求有thinking字段就保留，没有就不添加
+    } else if (reasoningLevel && ['low', 'medium', 'high'].includes(reasoningLevel)) {
       const budgetTokens = {
         'low': 4096,
         'medium': 12288,
diff --git a/transformers/request-anthropic.js b/transformers/request-anthropic.js
index 1fea716..52f6f41 100644
--- a/transformers/request-anthropic.js
+++ b/transformers/request-anthropic.js
@@ -113,7 +113,14 @@ export function transformToAnthropic(openaiRequest) {
 
   // Handle thinking field based on model configuration
   const reasoningLevel = getModelReasoning(openaiRequest.model);
-  if (reasoningLevel) {
+  if (reasoningLevel === 'auto') {
+    // Auto mode: preserve original request's thinking field exactly as-is
+    if (openaiRequest.thinking !== undefined) {
+      anthropicRequest.thinking = openaiRequest.thinking;
+    }
+    // If original request has no thinking field, don't add one
+  } else if (reasoningLevel && ['low', 'medium', 'high'].includes(reasoningLevel)) {
+    // Specific level: override with model configuration
     const budgetTokens = {
       'low': 4096,
       'medium': 12288,
@@ -125,7 +132,7 @@ export function transformToAnthropic(openaiRequest) {
       budget_tokens: budgetTokens[reasoningLevel]
     };
   } else {
-    // If reasoning is off or invalid, explicitly remove thinking field
+    // Off or invalid: explicitly remove thinking field
     // This ensures any thinking field from the original request is deleted
     delete anthropicRequest.thinking;
   }
@@ -179,7 +186,10 @@ export function getAnthropicHeaders(authHeader, clientHeaders = {}, isStreaming
   
   // Handle thinking beta based on reasoning configuration
   const thinkingBeta = 'interleaved-thinking-2025-05-14';
-  if (reasoningLevel) {
+  if (reasoningLevel === 'auto') {
+    // Auto mode: don't modify anthropic-beta header, preserve original
+    // betaValues remain unchanged from client headers
+  } else if (reasoningLevel && ['low', 'medium', 'high'].includes(reasoningLevel)) {
     // Add thinking beta if not already present
     if (!betaValues.includes(thinkingBeta)) {
       betaValues.push(thinkingBeta);
diff --git a/transformers/request-openai.js b/transformers/request-openai.js
index 2d6a44c..6490a54 100644
--- a/transformers/request-openai.js
+++ b/transformers/request-openai.js
@@ -94,14 +94,20 @@ export function transformToOpenAI(openaiRequest) {
 
   // Handle reasoning field based on model configuration
   const reasoningLevel = getModelReasoning(openaiRequest.model);
-  if (reasoningLevel) {
-    // Add reasoning field based on model configuration
+  if (reasoningLevel === 'auto') {
+    // Auto mode: preserve original request's reasoning field exactly as-is
+    if (openaiRequest.reasoning !== undefined) {
+      targetRequest.reasoning = openaiRequest.reasoning;
+    }
+    // If original request has no reasoning field, don't add one
+  } else if (reasoningLevel && ['low', 'medium', 'high'].includes(reasoningLevel)) {
+    // Specific level: override with model configuration
     targetRequest.reasoning = {
       effort: reasoningLevel,
       summary: 'auto'
     };
   } else {
-    // If reasoning is off or invalid, explicitly remove reasoning field
+    // Off or invalid: explicitly remove reasoning field
     // This ensures any reasoning field from the original request is deleted
     delete targetRequest.reasoning;
   }