Add tasks/delete method

Author: LucaButBoring

examples/shared/in_memory_task_store.py

@@ -134,6 +134,17 @@ async def list_tasks(self, cursor: str | None = None) -> dict[str, Any]:
 
         return {"tasks": tasks, "nextCursor": next_cursor}
 
+    async def delete_task(self, task_id: str) -> None:
+        """Delete a task from storage."""
+        if task_id not in self._tasks:
+            raise ValueError(f"Task with ID {task_id} not found")
+
+        # Cancel any scheduled cleanup
+        self._cancel_cleanup(task_id)
+
+        # Remove the task
+        self._tasks.pop(task_id)
+
     def _schedule_cleanup(self, task_id: str, delay_seconds: float) -> None:
         """Schedule automatic cleanup of a task after the specified delay."""
 

src/mcp/client/session.py

@@ -579,6 +579,15 @@ async def list_tasks(self, cursor: str | None = None) -> types.ListTasksResult:
             types.ListTasksResult,
         )
 
+    async def delete_task(self, task_id: str) -> types.EmptyResult:
+        """Delete a specific task."""
+        return await self.send_request(
+            types.ClientRequest(
+                types.DeleteTaskRequest(method="tasks/delete", params=types.DeleteTaskParams(taskId=task_id))
+            ),
+            types.EmptyResult,
+        )
+
     async def _received_request(self, responder: RequestResponder[types.ServerRequest, types.ClientResult]) -> None:
         ctx = RequestContext[ClientSession, Any](
             request_id=responder.request_id,

src/mcp/server/session.py

@@ -144,7 +144,9 @@ async def _receive_loop(self) -> None:
         async with self._incoming_message_stream_writer:
             await super()._receive_loop()
 
-    async def _received_request(self, responder: RequestResponder[types.ClientRequest, types.ServerResult]):
+    async def _received_request(  # noqa: PLR0912
+        self, responder: RequestResponder[types.ClientRequest, types.ServerResult]
+    ):
         # Handle task creation if task metadata is present
         if responder.request_meta and responder.request_meta.task and self._task_store:
             task_meta = responder.request_meta.task
@@ -275,6 +277,23 @@ async def _received_request(self, responder: RequestResponder[types.ClientReques
                         await responder.respond(
                             types.ErrorData(code=types.INVALID_REQUEST, message="Task store not configured")
                         )
+            case types.DeleteTaskRequest(params=params):
+                # Handle delete task requests if task store is available
+                if self._task_store:
+                    try:
+                        await self._task_store.delete_task(params.taskId)
+                        with responder:
+                            await responder.respond(types.ServerResult(types.EmptyResult(_meta={})))
+                    except Exception as e:
+                        with responder:
+                            await responder.respond(
+                                types.ErrorData(code=types.INVALID_PARAMS, message=f"Failed to delete task: {e}")
+                            )
+                else:
+                    with responder:
+                        await responder.respond(
+                            types.ErrorData(code=types.INVALID_REQUEST, message="Task store not configured")
+                        )
             case _:
                 if self._initialization_state != InitializationState.Initialized:
                     raise RuntimeError("Received request before initialization was complete")
@@ -459,6 +478,15 @@ async def list_tasks(self, cursor: str | None = None) -> types.ListTasksResult:
             types.ListTasksResult,
         )
 
+    async def delete_task(self, task_id: str) -> types.EmptyResult:
+        """Delete a specific task."""
+        return await self.send_request(
+            types.ServerRequest(
+                types.DeleteTaskRequest(method="tasks/delete", params=types.DeleteTaskParams(taskId=task_id))
+            ),
+            types.EmptyResult,
+        )
+
     async def _handle_incoming(self, req: ServerRequestResponder) -> None:
         await self._incoming_message_stream_writer.send(req)
 

src/mcp/shared/task.py

@@ -99,6 +99,19 @@ async def list_tasks(self, cursor: str | None = None) -> dict[str, list[Task] |
         """
         ...
 
+    @abstractmethod
+    async def delete_task(self, task_id: str) -> None:
+        """
+        Delete a task from storage.
+
+        Args:
+            task_id: The task identifier
+
+        Raises:
+            Exception: If task not found
+        """
+        ...
+
 
 def is_terminal(status: TaskStatus) -> bool:
     """

src/mcp/types.py

@@ -584,6 +584,22 @@ class ListTasksResult(Result):
     model_config = ConfigDict(extra="allow")
 
 
+class DeleteTaskParams(RequestParams):
+    """Parameters for deleting a task."""
+
+    taskId: str
+    """The task identifier."""
+
+    model_config = ConfigDict(extra="allow")
+
+
+class DeleteTaskRequest(Request[DeleteTaskParams, Literal["tasks/delete"]]):
+    """A request to delete a specific task."""
+
+    method: Literal["tasks/delete"] = "tasks/delete"
+    params: DeleteTaskParams
+
+
 class ListResourcesRequest(PaginatedRequest[Literal["resources/list"]]):
     """Sent from the client to request a list of resources the server has."""
 
@@ -1433,6 +1449,7 @@ class ClientRequest(
         | GetTaskRequest
         | GetTaskPayloadRequest
         | ListTasksRequest
+        | DeleteTaskRequest
     ]
 ):
     pass
@@ -1503,6 +1520,7 @@ class ServerRequest(
         | GetTaskRequest
         | GetTaskPayloadRequest
         | ListTasksRequest
+        | DeleteTaskRequest
     ]
 ):
     pass