diff --git a/README.md b/README.md
index a526ea5..c5bc535 100644
--- a/README.md
+++ b/README.md
@@ -21,13 +21,13 @@
   ```
 - 功能测试
   ```bash
-  mcp-get-weather --api-key YOUR_OPENWEATHER_KEY
+  mcp-get-weather
   ```
 - 启动后效果
   <img src="https://ml2022.oss-cn-hangzhou.aliyuncs.com/img/image-20250518154159197.png" alt="image-20250518154159197" style="zoom:50%;" />
 
 - 调用测试
-  &emsp;&emsp;需要注意的是，这是一个流式HTTP的用于天气查询的MCP服务器，默认项目功能是需要在启动时输入OpenWeather KEY，启动后在3000端口即可发起流式MCP工具调用请求。例如在Cherry Studio中，调用流式MCP进行天气查询如下：
+  &emsp;&emsp;需要注意的是，这是一个流式HTTP的用于天气查询的MCP服务器，当前代码已在内部定义 OpenWeather KEY，启动后在3000端口即可发起流式MCP工具调用请求。例如在Cherry Studio中，调用流式MCP进行天气查询如下：
   - 先创建MCP工具
     <img src="https://ml2022.oss-cn-hangzhou.aliyuncs.com/img/image-20250518154336437.png" alt="image-20250518154336437" style="zoom:50%;" />
   - 然后进行调用测试
diff --git a/src/mcp_get_weather/server.py b/src/mcp_get_weather/server.py
index 09424d0..51b6886 100644
--- a/src/mcp_get_weather/server.py
+++ b/src/mcp_get_weather/server.py
@@ -19,6 +19,7 @@
 OPENWEATHER_URL = "https://api.openweathermap.org/data/2.5/weather"
 DEFAULT_UNITS = "metric"  # use Celsius by default
 DEFAULT_LANG = "zh_cn"  # Chinese descriptions
+DEFAULT_API_KEY = "<YOUR_OPENWEATHER_API_KEY>"
 
 
 async def fetch_weather(city: str, api_key: str) -> dict[str, str]:
@@ -57,9 +58,9 @@ async def fetch_weather(city: str, api_key: str) -> dict[str, str]:
 @click.option("--port", default=3000, help="Port to listen on for HTTP")
 @click.option(
     "--api-key",
-    envvar="OPENWEATHER_API_KEY",
-    required=True,
-    help="OpenWeather API key (or set OPENWEATHER_API_KEY env var)",
+    default=lambda: os.environ.get("OPENWEATHER_API_KEY", DEFAULT_API_KEY),
+    show_default=False,
+    help="OpenWeather API key",
 )
 @click.option(
     "--log-level",