tiangolo.fastapi/add_query_method.patch

--- a/fastapi/routing.py
+++ b/fastapi/routing.py
@@ -2581,6 +2581,89 @@ class APIRouter:
             generate_unique_id_function=generate_unique_id_function,
         )

+    def query(
+        self,
+        path: Annotated[
+            str,
+            Doc(
+                """
+                The URL path to be used for this *path operation*.
+
+                For example, in `http://example.com/items`, the path is `/items`.
+                """
+            ),
+        ],
+        *,
+        response_model: Annotated[
+            Any,
+            Doc(
+                """
+                The type to use for the response.
+
+                It could be any valid Pydantic *field* type. So, it doesn't have to
+                be a Pydantic model, it could be other things, like a `list`, `dict`,
+                etc.
+
+                It will be used for:
+
+                * Documentation: the generated OpenAPI (and the UI at `/docs`) will
+                    show it as the response (JSON Schema).
+                * Serialization: you could return an arbitrary object and the
+                    `response_model` would be used to serialize that object into the
+                    corresponding JSON.
+                * Filtering: the JSON sent to the client will only contain the data
+                    (fields) defined in the `response_model`. If you returned an object
+                    that contains an attribute `password` but the `response_model` does
+                    not include that field, the JSON sent to the client would not have
+                    that `password`.
+                * Validation: whatever you return will be serialized with the
+                    `response_model`, converting any data as necessary to generate the
+                    corresponding JSON. But if the data in the object returned is not
+                    valid, that would mean a violation of the contract with the client,
+                    so it's an error from the API developer. So, FastAPI will raise an
+                    error and return a 500 error code (Internal Server Error).
+
+                Read more about it in the
+                [FastAPI docs for Response Model](https://fastapi.tiangolo.com/tutorial/response-model/).
+                """
+            ),
+        ] = Default(None),
+        status_code: Annotated[Optional[int], Doc("HTTP status code for the response")] = None,
+        tags: Annotated[Optional[List[Union[str, Enum]]], Doc("OpenAPI tags")] = None,
+        dependencies: Annotated[Optional[Sequence[params.Depends]], Doc("Dependencies")] = None,
+        summary: Annotated[Optional[str], Doc("OpenAPI summary")] = None,
+        description: Annotated[Optional[str], Doc("OpenAPI description")] = None,
+        response_description: Annotated[str, Doc("OpenAPI response description")] = "Successful Response",
+        responses: Annotated[Optional[Dict[Union[int, str], Dict[str, Any]]], Doc("Additional responses")] = None,
+        deprecated: Annotated[Optional[bool], Doc("Mark as deprecated")] = None,
+        operation_id: Annotated[Optional[str], Doc("OpenAPI operation ID")] = None,
+        response_model_include: Annotated[Optional[IncEx], Doc("Fields to include")] = None,
+        response_model_exclude: Annotated[Optional[IncEx], Doc("Fields to exclude")] = None,
+        response_model_by_alias: Annotated[bool, Doc("Use field aliases")] = True,
+        response_model_exclude_unset: Annotated[bool, Doc("Exclude unset fields")] = False,
+        response_model_exclude_defaults: Annotated[bool, Doc("Exclude default values")] = False,
+        response_model_exclude_none: Annotated[bool, Doc("Exclude None values")] = False,
+        include_in_schema: Annotated[bool, Doc("Include in OpenAPI schema")] = True,
+        response_class: Annotated[
+            Union[Type[Response], DefaultPlaceholder],
+            Doc("Response class to use"),
+        ] = Default(JSONResponse),
+        name: Annotated[Optional[str], Doc("Name for the operation")] = None,
+        callbacks: Annotated[Optional[List[BaseRoute]], Doc("OpenAPI callbacks")] = None,
+        openapi_extra: Annotated[Optional[Dict[str, Any]], Doc("Extra OpenAPI data")] = None,
+        generate_unique_id_function: Annotated[
+            Callable[[APIRoute], str], Doc("Function to generate unique IDs")
+        ] = Default(generate_unique_id),
+    ) -> Callable[[DecoratedCallable], DecoratedCallable]:
+        """
+        Add a *path operation* using an HTTP QUERY operation.
+
+        The QUERY method is a safe HTTP method that allows request bodies,
+        useful for complex queries that exceed URL length limits.
+
+        See: https://www.ietf.org/archive/id/draft-ietf-httpbis-safe-method-w-body-02.html
+        """
+        return self.api_route(
+            path=path,
+            response_model=response_model,
+            status_code=status_code,
+            tags=tags,
+            dependencies=dependencies,
+            summary=summary,
+            description=description,
+            response_description=response_description,
+            responses=responses,
+            deprecated=deprecated,
+            methods=["QUERY"],
+            operation_id=operation_id,
+            response_model_include=response_model_include,
+            response_model_exclude=response_model_exclude,
+            response_model_by_alias=response_model_by_alias,
+            response_model_exclude_unset=response_model_exclude_unset,
+            response_model_exclude_defaults=response_model_exclude_defaults,
+            response_model_exclude_none=response_model_exclude_none,
+            include_in_schema=include_in_schema,
+            response_class=response_class,
+            name=name,
+            callbacks=callbacks,
+            openapi_extra=openapi_extra,
+            generate_unique_id_function=generate_unique_id_function,
+        )
+
     def delete(
         self,
         path: Annotated[