remove base_url param entirely

Author: shahar4499

README_zh-CN.md

@@ -47,23 +47,14 @@ from fastapi_mcp import FastApiMCP
 
 app = FastAPI()
 
-mcp = FastApiMCP(
-    app,
-
-    # 可选参数
-    name="我的 API MCP",
-    description="我的 API 描述",
-    base_url="http://localhost:8000",
-)
+mcp = FastApiMCP(app)
 
 # 直接将 MCP 服务器挂载到您的 FastAPI 应用
 mcp.mount()
 ```
 
 就是这样！您的自动生成的 MCP 服务器现在可以在 `https://app.base.url/mcp` 访问。
 
-> **关于`base_url`的注意事项**：虽然`base_url`是可选的，但强烈建议您明确提供它。`base_url` 告诉 MCP 服务器在调用工具时向何处发送 API 请求。如果不提供，库将尝试自动确定 URL，这在部署环境中内部和外部 URL 不同时可能无法正确工作。
-
 ## 工具命名
 
 FastAPI-MCP 使用 FastAPI 路由中的`operation_id`作为 MCP 工具的名称。如果您不指定`operation_id`，FastAPI 会自动生成一个，但这些名称可能比较晦涩。
@@ -101,7 +92,6 @@ app = FastAPI()
 mcp = FastApiMCP(
     app,
     name="我的 API MCP",
-    base_url="http://localhost:8000",
     describe_all_responses=True,     # 在工具描述中包含所有可能的响应模式
     describe_full_response_schema=True  # 在工具描述中包含完整的 JSON 模式
 )
@@ -177,10 +167,7 @@ api_app = FastAPI()
 mcp_app = FastAPI()
 
 # 从 API 应用创建 MCP 服务器
-mcp = FastApiMCP(
-    api_app,
-    base_url="http://api-host:8001",  # API 应用将运行的 URL
-)
+mcp = FastApiMCP(api_app)
 
 # 将 MCP 服务器挂载到单独的应用
 mcp.mount(mcp_app)

examples/mount_specific_router_example.py

@@ -17,7 +17,6 @@
     app,
     name="Item API MCP",
     description="MCP server for the Item API",
-    base_url="http://localhost:8000",
 )
 
 # Mount the MCP server to a specific router.

fastapi_mcp/server.py

@@ -23,15 +23,6 @@ def __init__(
         fastapi: FastAPI,
         name: Optional[str] = None,
         description: Optional[str] = None,
-        base_url: Annotated[
-            Optional[str],
-            Doc(
-                """
-                Optionally specify an explicit base URL for the API server.
-                This is only needed if FastApiMCP is deployed or mounted separately from the FastAPI app.
-                """
-            ),
-        ] = None,
         describe_all_responses: bool = False,
         describe_full_response_schema: bool = False,
         http_client: Annotated[
@@ -55,13 +46,8 @@ def __init__(
             fastapi: The FastAPI application
             name: Name for the MCP server (defaults to app.title)
             description: Description for the MCP server (defaults to app.description)
-            base_url: Base URL for API requests. If not provided, the base URL will be determined from the
-                FastAPI app's root path. Although optional, it is highly recommended to provide a base URL,
-                as the root path would be different when the app is deployed.
             describe_all_responses: Whether to include all possible response schemas in tool descriptions
             describe_full_response_schema: Whether to include full json schema for responses in tool descriptions
-            http_client: Optional HTTP client to use for API calls. If not provided, a new httpx.AsyncClient will be created.
-                This is primarily for testing purposes.
             include_operations: List of operation IDs to include as MCP tools. Cannot be used with exclude_operations.
             exclude_operations: List of operation IDs to exclude from MCP tools. Cannot be used with include_operations.
             include_tags: List of tags to include as MCP tools. Cannot be used with exclude_tags.
@@ -82,7 +68,7 @@ def __init__(
         self.name = name or self.fastapi.title or "FastAPI MCP"
         self.description = description or self.fastapi.description
 
-        self._base_url = base_url or "http://apiserver"
+        self._base_url = "http://apiserver"
         self._describe_all_responses = describe_all_responses
         self._describe_full_response_schema = describe_full_response_schema
         self._include_operations = include_operations
@@ -118,10 +104,6 @@ def setup_server(self) -> None:
         # Filter tools based on operation IDs and tags
         self.tools = self._filter_tools(all_tools, openapi_schema)
 
-        # Normalize base URL
-        if self._base_url.endswith("/"):
-            self._base_url = self._base_url[:-1]
-
         # Create the MCP lowlevel server
         mcp_server: Server = Server(self.name, self.description)
 
@@ -228,7 +210,6 @@ async def _execute_api_tool(
         Execute an MCP tool by making an HTTP request to the corresponding API endpoint.
 
         Args:
-            base_url: The base URL for the API
             tool_name: The name of the tool to execute
             arguments: The arguments for the tool
             operation_map: A mapping from tool names to operation details

tests/test_basic_functionality.py

@@ -10,13 +10,11 @@ def test_create_mcp_server(simple_fastapi_app: FastAPI):
         simple_fastapi_app,
         name="Test MCP Server",
         description="Test description",
-        base_url="http://localhost:8000",
     )
 
     # Verify the MCP server was created correctly
     assert mcp.name == "Test MCP Server"
     assert mcp.description == "Test description"
-    assert mcp._base_url == "http://localhost:8000"
     assert isinstance(mcp.server, Server)
     assert len(mcp.tools) > 0, "Should have extracted tools from the app"
     assert len(mcp.operation_map) > 0, "Should have operation mapping"
@@ -35,9 +33,6 @@ def test_default_values(simple_fastapi_app: FastAPI):
     assert mcp.name == simple_fastapi_app.title
     assert mcp.description == simple_fastapi_app.description
 
-    # Default base URL should be derived or defaulted
-    assert mcp._base_url is not None
-
     # Mount with default path
     mcp.mount()
 

tests/test_configuration.py

@@ -13,10 +13,6 @@ def test_default_configuration(simple_fastapi_app: FastAPI):
     assert mcp_server.name == simple_fastapi_app.title
     assert mcp_server.description == simple_fastapi_app.description
 
-    # Check default base URL
-    assert mcp_server._base_url is not None
-    assert mcp_server._base_url.startswith("http://")
-
     # Check default options
     assert mcp_server._describe_all_responses is False
     assert mcp_server._describe_full_response_schema is False
@@ -27,13 +23,11 @@ def test_custom_configuration(simple_fastapi_app: FastAPI):
     # Create MCP server with custom options
     custom_name = "Custom MCP Server"
     custom_description = "A custom MCP server for testing"
-    custom_base_url = "https://custom-api.example.com"
 
     mcp_server = FastApiMCP(
         simple_fastapi_app,
         name=custom_name,
         description=custom_description,
-        base_url=custom_base_url,
         describe_all_responses=True,
         describe_full_response_schema=True,
     )
@@ -42,41 +36,19 @@ def test_custom_configuration(simple_fastapi_app: FastAPI):
     assert mcp_server.name == custom_name
     assert mcp_server.description == custom_description
 
-    # Check custom base URL
-    assert mcp_server._base_url == custom_base_url
-
     # Check custom options
     assert mcp_server._describe_all_responses is True
     assert mcp_server._describe_full_response_schema is True
 
 
-def test_base_url_normalization(simple_fastapi_app: FastAPI):
-    """Test that base URLs are normalized correctly."""
-    # Test with trailing slash
-    mcp_server1 = FastApiMCP(
-        simple_fastapi_app,
-        base_url="http://example.com/api/",
-    )
-    assert mcp_server1._base_url == "http://example.com/api"
-
-    # Test without trailing slash
-    mcp_server2 = FastApiMCP(
-        simple_fastapi_app,
-        base_url="http://example.com/api",
-    )
-    assert mcp_server2._base_url == "http://example.com/api"
-
-
 def test_describe_all_responses_config_simple_app(simple_fastapi_app: FastAPI):
     """Test the describe_all_responses behavior with the simple app."""
     mcp_default = FastApiMCP(
         simple_fastapi_app,
-        base_url="http://example.com",
     )
 
     mcp_all_responses = FastApiMCP(
         simple_fastapi_app,
-        base_url="http://example.com",
         describe_all_responses=True,
     )
 
@@ -136,7 +108,6 @@ def test_describe_full_response_schema_config_simple_app(simple_fastapi_app: Fas
 
     mcp_full_response_schema = FastApiMCP(
         simple_fastapi_app,
-        base_url="http://example.com",
         describe_full_response_schema=True,
     )
 
@@ -170,7 +141,6 @@ def test_describe_all_responses_and_full_response_schema_config_simple_app(simpl
 
     mcp_all_responses_and_full_response_schema = FastApiMCP(
         simple_fastapi_app,
-        base_url="http://example.com",
         describe_all_responses=True,
         describe_full_response_schema=True,
     )
@@ -208,12 +178,10 @@ def test_describe_all_responses_config_complex_app(complex_fastapi_app: FastAPI)
     """Test the describe_all_responses behavior with the complex app."""
     mcp_default = FastApiMCP(
         complex_fastapi_app,
-        base_url="http://example.com",
     )
 
     mcp_all_responses = FastApiMCP(
         complex_fastapi_app,
-        base_url="http://example.com",
         describe_all_responses=True,
     )
 
@@ -281,7 +249,6 @@ def test_describe_full_response_schema_config_complex_app(complex_fastapi_app: F
     """Test the describe_full_response_schema behavior with the complex app."""
     mcp_full_response_schema = FastApiMCP(
         complex_fastapi_app,
-        base_url="http://example.com",
         describe_full_response_schema=True,
     )
 
@@ -326,7 +293,6 @@ def test_describe_all_responses_and_full_response_schema_config_complex_app(comp
     """Test the describe_all_responses and describe_full_response_schema together with the complex app."""
     mcp_all_responses_and_full_schema = FastApiMCP(
         complex_fastapi_app,
-        base_url="http://example.com",
         describe_all_responses=True,
         describe_full_response_schema=True,
     )