diff --git a/.env.example b/.env.example
new file mode 100644
index 0000000..d8b0faa
--- /dev/null
+++ b/.env.example
@@ -0,0 +1,6 @@
+# OpenAI API Key
+OPENAI_API_KEY=sk-your-api-key-here
+
+# 可选：自定义路由阈值
+# ROUTE_SIMPLE_THRESHOLD=100
+# ROUTE_MEDIUM_THRESHOLD=500
diff --git a/config.py b/config.py
index 3275d4e..e79abff 100644
--- a/config.py
+++ b/config.py
@@ -3,7 +3,10 @@
 """
 import os
 from typing import Literal
+from dotenv import load_dotenv
 
+# 加载 .env 文件
+load_dotenv()
 
 # 模型配置
 MODEL_CONFIG = {
diff --git a/requirements.txt b/requirements.txt
index c9d22f4..ccbd1d2 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,5 +4,6 @@ pydantic>=2.5.0
 openai>=1.6.0
 tiktoken>=0.5.0
 httpx>=0.25.0
+python-dotenv>=1.0.0
 pytest>=7.4.0
 pytest-asyncio>=0.21.0