Support enabled/disabled prompts

src/fastmcp/prompts/prompt.py

@@ -96,6 +96,7 @@ class Prompt(FastMCPComponent, ABC):
         name: str | None = None,
         description: str | None = None,
         tags: set[str] | None = None,
+        enabled: bool | None = None,
     ) -> FunctionPrompt:
         """Create a Prompt from a function.
 
@@ -106,7 +107,7 @@ class Prompt(FastMCPComponent, ABC):
         - A sequence of any of the above
         """
         return FunctionPrompt.from_function(
-            fn=fn, name=name, description=description, tags=tags
+            fn=fn, name=name, description=description, tags=tags, enabled=enabled
         )
 
     @abstractmethod
@@ -130,6 +131,7 @@ class FunctionPrompt(Prompt):
         name: str | None = None,
         description: str | None = None,
         tags: set[str] | None = None,
+        enabled: bool | None = None,
     ) -> FunctionPrompt:
         """Create a Prompt from a function.
 
@@ -195,6 +197,7 @@ class FunctionPrompt(Prompt):
             description=description,
             arguments=arguments,
             tags=tags or set(),
+            enabled=enabled if enabled is not None else True,
             fn=fn,
         )
 

src/fastmcp/prompts/prompt_manager.py

@@ -40,9 +40,11 @@ class PromptManager:
 
         self.duplicate_behavior = duplicate_behavior
 
-    def get_prompt(self, key: str) -> Prompt | None:
+    def get_prompt(self, key: str) -> Prompt:
         """Get prompt by key."""
-        return self._prompts.get(key)
+        if key in self._prompts:
+            return self._prompts[key]
+        raise NotFoundError(f"Unknown prompt: {key}")
 
     def get_prompts(self) -> dict[str, Prompt]:
         """Get all registered prompts, indexed by registered key."""

src/fastmcp/server/server.py

@@ -940,6 +940,7 @@ class FastMCP(Generic[LifespanResultT]):
         name: str | None = None,
         description: str | None = None,
         tags: set[str] | None = None,
+        enabled: bool | None = None,
     ) -> FunctionPrompt: ...
 
     @overload
@@ -950,6 +951,7 @@ class FastMCP(Generic[LifespanResultT]):
         name: str | None = None,
         description: str | None = None,
         tags: set[str] | None = None,
+        enabled: bool | None = None,
     ) -> Callable[[AnyFunction], FunctionPrompt]: ...
 
     def prompt(
@@ -959,6 +961,7 @@ class FastMCP(Generic[LifespanResultT]):
         name: str | None = None,
         description: str | None = None,
         tags: set[str] | None = None,
+        enabled: bool | None = None,
     ) -> Callable[[AnyFunction], FunctionPrompt] | FunctionPrompt:
         """Decorator to register a prompt.
 
@@ -1050,6 +1053,7 @@ class FastMCP(Generic[LifespanResultT]):
                 name=prompt_name,
                 description=description,
                 tags=tags,
+                enabled=enabled,
             )
             self.add_prompt(prompt)
 
@@ -1077,6 +1081,7 @@ class FastMCP(Generic[LifespanResultT]):
             name=prompt_name,
             description=description,
             tags=tags,
+            enabled=enabled,
         )
 
     async def run_stdio_async(self) -> None: