func → fn everywhere

src/fastmcp/resources/resource_manager.py

@@ -19,9 +19,35 @@ class ResourceManager:
         self._templates: Dict[str, ResourceTemplate] = {}
         self.warn_on_duplicate_resources = warn_on_duplicate_resources
 
+    def add_resource(self, resource: Resource) -> Resource:
+        """Add a resource to the manager.
+
+        Args:
+            resource: A Resource instance to add
+
+        Returns:
+            The added resource. If a resource with the same URI already exists,
+            returns the existing resource.
+        """
+        logger.debug(
+            "Adding resource",
+            extra={
+                "uri": resource.uri,
+                "type": type(resource).__name__,
+                "name": resource.name,
+            },
+        )
+        existing = self._resources.get(str(resource.uri))
+        if existing:
+            if self.warn_on_duplicate_resources:
+                logger.warning(f"Resource already exists: {resource.uri}")
+            return existing
+        self._resources[str(resource.uri)] = resource
+        return resource
+
     def add_template(
         self,
-        func: Callable,
+        fn: Callable,
         uri_template: str,
         name: Optional[str] = None,
         description: Optional[str] = None,
@@ -29,7 +55,7 @@ class ResourceManager:
     ) -> ResourceTemplate:
         """Add a template from a function."""
         template = ResourceTemplate.from_function(
-            func,
+            fn,
             uri_template=uri_template,
             name=name,
             description=description,
@@ -66,29 +92,3 @@ class ResourceManager:
         """List all registered templates."""
         logger.debug("Listing templates", extra={"count": len(self._templates)})
         return list(self._templates.values())
-
-    def add_resource(self, resource: Resource) -> Resource:
-        """Add a resource to the manager.
-
-        Args:
-            resource: A Resource instance to add
-
-        Returns:
-            The added resource. If a resource with the same URI already exists,
-            returns the existing resource.
-        """
-        logger.debug(
-            "Adding resource",
-            extra={
-                "uri": resource.uri,
-                "type": type(resource).__name__,
-                "name": resource.name,
-            },
-        )
-        existing = self._resources.get(str(resource.uri))
-        if existing:
-            if self.warn_on_duplicate_resources:
-                logger.warning(f"Resource already exists: {resource.uri}")
-            return existing
-        self._resources[str(resource.uri)] = resource
-        return resource

src/fastmcp/resources/templates.py

@@ -20,35 +20,35 @@ class ResourceTemplate(BaseModel):
     mime_type: str = Field(
         default="text/plain", description="MIME type of the resource content"
     )
-    func: Callable = Field(exclude=True)
+    fn: Callable = Field(exclude=True)
     parameters: dict = Field(description="JSON schema for function parameters")
 
     @classmethod
     def from_function(
         cls,
-        func: Callable,
+        fn: Callable,
         uri_template: str,
         name: Optional[str] = None,
         description: Optional[str] = None,
         mime_type: Optional[str] = None,
     ) -> "ResourceTemplate":
         """Create a template from a function."""
-        func_name = name or func.__name__
+        func_name = name or fn.__name__
         if func_name == "<lambda>":
             raise ValueError("You must provide a name for lambda functions")
 
         # Get schema from TypeAdapter - will fail if function isn't properly typed
-        parameters = TypeAdapter(func).json_schema()
+        parameters = TypeAdapter(fn).json_schema()
 
         # ensure the arguments are properly cast
-        func = validate_call(func)
+        fn = validate_call(fn)
 
         return cls(
             uri_template=uri_template,
             name=func_name,
-            description=description or func.__doc__ or "",
+            description=description or fn.__doc__ or "",
             mime_type=mime_type or "text/plain",
-            func=func,
+            fn=fn,
             parameters=parameters,
         )
 
@@ -65,7 +65,7 @@ class ResourceTemplate(BaseModel):
         """Create a resource from the template with the given parameters."""
         try:
             # Call function and check if result is a coroutine
-            result = self.func(**params)
+            result = self.fn(**params)
             if inspect.iscoroutine(result):
                 result = await result
 
@@ -74,7 +74,7 @@ class ResourceTemplate(BaseModel):
                 name=self.name,
                 description=self.description,
                 mime_type=self.mime_type,
-                func=lambda: result,  # Capture result in closure
+                fn=lambda: result,  # Capture result in closure
             )
         except Exception as e:
             raise ValueError(f"Error creating resource from template: {e}")

src/fastmcp/resources/types.py

@@ -46,12 +46,12 @@ class FunctionResource(Resource):
     - other types will be converted to JSON
     """
 
-    func: Callable[[], Any] = Field(exclude=True)
+    fn: Callable[[], Any] = Field(exclude=True)
 
     async def read(self) -> Union[str, bytes]:
         """Read the resource by calling the wrapped function."""
         try:
-            result = self.func()
+            result = self.fn()
             if isinstance(result, Resource):
                 return await result.read()
             if isinstance(result, bytes):

src/fastmcp/server.py

@@ -188,7 +188,7 @@ class FastMCP:
 
     def add_tool(
         self,
-        func: Callable,
+        fn: Callable,
         name: Optional[str] = None,
         description: Optional[str] = None,
     ) -> None:
@@ -198,11 +198,11 @@ class FastMCP:
         with the Context type annotation. See the @tool decorator for examples.
 
         Args:
-            func: The function to register as a tool
+            fn: The function to register as a tool
             name: Optional name for the tool (defaults to function name)
             description: Optional description of what the tool does
         """
-        self._tool_manager.add_tool(func, name=name, description=description)
+        self._tool_manager.add_tool(fn, name=name, description=description)
 
     def tool(
         self, name: Optional[str] = None, description: Optional[str] = None
@@ -238,9 +238,9 @@ class FastMCP:
                 "Did you forget to call it? Use @tool() instead of @tool"
             )
 
-        def decorator(func: Callable) -> Callable:
-            self.add_tool(func, name=name, description=description)
-            return func
+        def decorator(fn: Callable) -> Callable:
+            self.add_tool(fn, name=name, description=description)
+            return fn
 
         return decorator
 
@@ -293,19 +293,19 @@ class FastMCP:
                 "Did you forget to call it? Use @resource('uri') instead of @resource"
             )
 
-        def decorator(func: Callable) -> Callable:
-            @functools.wraps(func)
+        def decorator(fn: Callable) -> Callable:
+            @functools.wraps(fn)
             def wrapper(*args: Any, **kwargs: Any) -> Any:
-                return func(*args, **kwargs)
+                return fn(*args, **kwargs)
 
             # Check if this should be a template
             has_uri_params = "{" in uri and "}" in uri
-            has_func_params = bool(inspect.signature(func).parameters)
+            has_func_params = bool(inspect.signature(fn).parameters)
 
             if has_uri_params or has_func_params:
                 # Validate that URI params match function params
                 uri_params = set(re.findall(r"{(\w+)}", uri))
-                func_params = set(inspect.signature(func).parameters.keys())
+                func_params = set(inspect.signature(fn).parameters.keys())
 
                 if uri_params != func_params:
                     raise ValueError(
@@ -328,7 +328,7 @@ class FastMCP:
                     name=name,
                     description=description,
                     mime_type=mime_type or "text/plain",
-                    func=wrapper,
+                    fn=wrapper,
                 )
                 self.add_resource(resource)
             return wrapper

src/fastmcp/tools/base.py

@@ -15,7 +15,7 @@ if TYPE_CHECKING:
 class Tool(BaseModel):
     """Internal tool registration info."""
 
-    func: Callable = Field(exclude=True)
+    fn: Callable = Field(exclude=True)
     name: str = Field(description="Name of the tool")
     description: str = Field(description="Description of what the tool does")
     parameters: dict = Field(description="JSON schema for tool parameters")
@@ -27,36 +27,36 @@ class Tool(BaseModel):
     @classmethod
     def from_function(
         cls,
-        func: Callable,
+        fn: Callable,
         name: Optional[str] = None,
         description: Optional[str] = None,
         context_kwarg: Optional[str] = None,
     ) -> "Tool":
         """Create a Tool from a function."""
-        func_name = name or func.__name__
+        func_name = name or fn.__name__
 
         if func_name == "<lambda>":
             raise ValueError("You must provide a name for lambda functions")
 
-        func_doc = description or func.__doc__ or ""
-        is_async = inspect.iscoroutinefunction(func)
+        func_doc = description or fn.__doc__ or ""
+        is_async = inspect.iscoroutinefunction(fn)
 
         # Get schema from TypeAdapter - will fail if function isn't properly typed
-        parameters = TypeAdapter(func).json_schema()
+        parameters = TypeAdapter(fn).json_schema()
 
         # Find context parameter if it exists
         if context_kwarg is None:
-            sig = inspect.signature(func)
+            sig = inspect.signature(fn)
             for param_name, param in sig.parameters.items():
                 if param.annotation is fastmcp.Context:
                     context_kwarg = param_name
                     break
 
         # ensure the arguments are properly cast
-        func = validate_call(func)
+        fn = validate_call(fn)
 
         return cls(
-            func=func,
+            fn=fn,
             name=func_name,
             description=func_doc,
             parameters=parameters,
@@ -73,7 +73,7 @@ class Tool(BaseModel):
 
             # Call function with proper async handling
             if self.is_async:
-                return await self.func(**arguments)
-            return self.func(**arguments)
+                return await self.fn(**arguments)
+            return self.fn(**arguments)
         except Exception as e:
             raise ToolError(f"Error executing tool {self.name}: {e}") from e

src/fastmcp/tools/tool_manager.py

@@ -30,12 +30,12 @@ class ToolManager:
 
     def add_tool(
         self,
-        func: Callable,
+        fn: Callable,
         name: Optional[str] = None,
         description: Optional[str] = None,
     ) -> Tool:
         """Add a tool to the server."""
-        tool = Tool.from_function(func, name=name, description=description)
+        tool = Tool.from_function(fn, name=name, description=description)
         existing = self._tools.get(tool.name)
         if existing:
             if self.warn_on_duplicate_tools:

tests/resources/test_function_resources.py

@@ -16,13 +16,13 @@ class TestFunctionResource:
             uri="fn://test",
             name="test",
             description="test function",
-            func=my_func,
+            fn=my_func,
         )
         assert str(resource.uri) == "fn://test"
         assert resource.name == "test"
         assert resource.description == "test function"
         assert resource.mime_type == "text/plain"  # default
-        assert resource.func == my_func
+        assert resource.fn == my_func
 
     async def test_read_text(self):
         """Test reading text from a FunctionResource."""
@@ -33,7 +33,7 @@ class TestFunctionResource:
         resource = FunctionResource(
             uri="function://test",
             name="test",
-            func=get_data,
+            fn=get_data,
         )
         content = await resource.read()
         assert content == "Hello, world!"
@@ -48,7 +48,7 @@ class TestFunctionResource:
         resource = FunctionResource(
             uri="function://test",
             name="test",
-            func=get_data,
+            fn=get_data,
         )
         content = await resource.read()
         assert content == b"Hello, world!"
@@ -62,7 +62,7 @@ class TestFunctionResource:
         resource = FunctionResource(
             uri="function://test",
             name="test",
-            func=get_data,
+            fn=get_data,
         )
         content = await resource.read()
         assert '"key": "value"' in content
@@ -76,7 +76,7 @@ class TestFunctionResource:
         resource = FunctionResource(
             uri="function://test",
             name="test",
-            func=failing_func,
+            fn=failing_func,
         )
         with pytest.raises(ValueError, match="Error reading resource function://test"):
             await resource.read()
@@ -90,7 +90,7 @@ class TestFunctionResource:
         resource = FunctionResource(
             uri="function://test",
             name="test",
-            func=lambda: MyModel(name="test"),
+            fn=lambda: MyModel(name="test"),
         )
         content = await resource.read()
         assert content == '{"name": "test"}'
@@ -108,7 +108,7 @@ class TestFunctionResource:
         resource = FunctionResource(
             uri="function://test",
             name="test",
-            func=get_data,
+            fn=get_data,
         )
         content = await resource.read()
         assert isinstance(content, str)

tests/resources/test_resource_manager.py

@@ -99,7 +99,7 @@ class TestResourceManager:
             return f"Hello, {name}!"
 
         template = ResourceTemplate.from_function(
-            func=greet,
+            fn=greet,
             uri_template="greet://{name}",
             name="greeter",
         )

tests/resources/test_resource_template.py

@@ -12,7 +12,7 @@ class TestResourceTemplate:
             return f"Weather in {city} ({units})"
 
         template = ResourceTemplate.from_function(
-            func=weather,
+            fn=weather,
             uri_template="weather://{city}/current",
             name="weather",
             description="Get current weather",
@@ -29,7 +29,7 @@ class TestResourceTemplate:
             ValueError, match="You must provide a name for lambda functions"
         ):
             ResourceTemplate.from_function(
-                func=lambda x: x,
+                fn=lambda x: x,
                 uri_template="test://{x}",
             )
 
@@ -40,7 +40,7 @@ class TestResourceTemplate:
             return x
 
         template = ResourceTemplate.from_function(
-            func=dummy,
+            fn=dummy,
             uri_template="test://{x}/value",
             name="test",
         )
@@ -60,7 +60,7 @@ class TestResourceTemplate:
             return f"Hello, {name}!"
 
         template = ResourceTemplate.from_function(
-            func=greet,
+            fn=greet,
             uri_template="greet://{name}",
             name="greeter",
         )
@@ -81,7 +81,7 @@ class TestResourceTemplate:
             return value.encode()
 
         template = ResourceTemplate.from_function(
-            func=get_bytes,
+            fn=get_bytes,
             uri_template="bytes://{value}",
             name="bytes",
         )
@@ -102,7 +102,7 @@ class TestResourceTemplate:
             return {"key": key, "value": 123}
 
         template = ResourceTemplate.from_function(
-            func=get_data,
+            fn=get_data,
             uri_template="data://{key}",
             name="data",
         )
@@ -124,7 +124,7 @@ class TestResourceTemplate:
             raise ValueError("Test error")
 
         template = ResourceTemplate.from_function(
-            func=failing_func,
+            fn=failing_func,
             uri_template="fail://{x}",
             name="fail",
         )
@@ -139,7 +139,7 @@ class TestResourceTemplate:
             return f"Hello, {name}!"
 
         template = ResourceTemplate.from_function(
-            func=greet,
+            fn=greet,
             uri_template="greet://{name}",
             name="greeter",
         )
@@ -160,7 +160,7 @@ class TestResourceTemplate:
             return value.encode()
 
         template = ResourceTemplate.from_function(
-            func=get_bytes,
+            fn=get_bytes,
             uri_template="bytes://{value}",
             name="bytes",
         )
@@ -181,7 +181,7 @@ class TestResourceTemplate:
             return {"key": key, "value": 123}
 
         template = ResourceTemplate.from_function(
-            func=get_data,
+            fn=get_data,
             uri_template="data://{key}",
             name="data",
         )
@@ -203,7 +203,7 @@ class TestResourceTemplate:
             raise ValueError("Test error")
 
         template = ResourceTemplate.from_function(
-            func=failing_func,
+            fn=failing_func,
             uri_template="fail://{x}",
             name="fail",
         )
@@ -223,7 +223,7 @@ class TestResourceTemplate:
             return async_helper(name)  # Returns coroutine
 
         template = ResourceTemplate.from_function(
-            func=get_greeting,
+            fn=get_greeting,
             uri_template="greet://{name}",
             name="greeter",
         )

tests/resources/test_resources.py

@@ -15,7 +15,7 @@ class TestResourceValidation:
         resource = FunctionResource(
             uri="http://example.com/data",
             name="test",
-            func=dummy_func,
+            fn=dummy_func,
         )
         assert str(resource.uri) == "http://example.com/data"
 
@@ -24,7 +24,7 @@ class TestResourceValidation:
             FunctionResource(
                 uri="invalid",
                 name="test",
-                func=dummy_func,
+                fn=dummy_func,
             )
 
         # Missing host
@@ -32,7 +32,7 @@ class TestResourceValidation:
             FunctionResource(
                 uri="http://",
                 name="test",
-                func=dummy_func,
+                fn=dummy_func,
             )
 
     def test_resource_name_from_uri(self):
@@ -43,7 +43,7 @@ class TestResourceValidation:
 
         resource = FunctionResource(
             uri="resource://my-resource",
-            func=dummy_func,
+            fn=dummy_func,
         )
         assert resource.name == "my-resource"
 
@@ -56,14 +56,14 @@ class TestResourceValidation:
         # Must provide either name or URI
         with pytest.raises(ValueError, match="Either name or uri must be provided"):
             FunctionResource(
-                func=dummy_func,
+                fn=dummy_func,
             )
 
         # Explicit name takes precedence over URI
         resource = FunctionResource(
             uri="resource://uri-name",
             name="explicit-name",
-            func=dummy_func,
+            fn=dummy_func,
         )
         assert resource.name == "explicit-name"
 
@@ -76,14 +76,14 @@ class TestResourceValidation:
         # Default mime type
         resource = FunctionResource(
             uri="resource://test",
-            func=dummy_func,
+            fn=dummy_func,
         )
         assert resource.mime_type == "text/plain"
 
         # Custom mime type
         resource = FunctionResource(
             uri="resource://test",
-            func=dummy_func,
+            fn=dummy_func,
             mime_type="application/json",
         )
         assert resource.mime_type == "application/json"

tests/test_server.py

@@ -205,7 +205,7 @@ class TestServerResources:
         def get_text():
             return "Hello, world!"
 
-        resource = FunctionResource(uri="resource://test", name="test", func=get_text)
+        resource = FunctionResource(uri="resource://test", name="test", fn=get_text)
         mcp.add_resource(resource)
 
         async with client_session(mcp._mcp_server) as client:
@@ -221,7 +221,7 @@ class TestServerResources:
         resource = FunctionResource(
             uri="resource://binary",
             name="binary",
-            func=get_binary,
+            fn=get_binary,
             is_binary=True,
             mime_type="application/octet-stream",
         )