✨ Add support for `app.query()` and `router.query()` (HTTP `QUERY` method)

Add first-class support for `QUERY`, a new HTTP method standardized in
RFC 10008 ("The HTTP QUERY Method", June 2026). `QUERY` is a safe,
idempotent method that carries a request body, so a client can send the
query in the request content instead of encoding it in the URI (like
`GET`, but with a body).

* Add `FastAPI.query()` and `APIRouter.query()` path operation
  decorators, mirroring the existing HTTP method decorators
  (`get`, `post`, ..., `trace`), registering routes with
  `methods=["QUERY"]`.
* Add `QUERY` to `METHODS_WITH_BODY` so the request body is documented
  in the generated OpenAPI schema.
* Document `query` in the FastAPI and APIRouter API reference and in the
  "First Steps" tutorial alongside the other HTTP methods.
* Add tests covering app- and router-level registration, `add_api_route`,
  body parsing, validation errors, 405 on the wrong method, GET/QUERY
  coexistence on the same path, and the full generated OpenAPI schema
  (via inline_snapshot).

Ref: https://datatracker.ietf.org/doc/rfc10008/
Signed-off-by: Itamar Shalev <[email protected]>

docs/en/docs/reference/apirouter.md

@@ -22,4 +22,5 @@ from fastapi import APIRouter
             - head
             - patch
             - trace
+            - query
             - on_event

docs/en/docs/reference/fastapi.md

@@ -27,6 +27,7 @@ from fastapi import FastAPI
             - head
             - patch
             - trace
+            - query
             - on_event
             - middleware
             - exception_handler

docs/en/docs/tutorial/first-steps.md

@@ -287,6 +287,7 @@ One of:
 * `HEAD`
 * `PATCH`
 * `TRACE`
+* `QUERY`
 
 In the HTTP protocol, you can communicate to each path using one (or more) of these "methods".
 
@@ -340,6 +341,7 @@ And the more exotic ones:
 * `@app.head()`
 * `@app.patch()`
 * `@app.trace()`
+* `@app.query()`
 
 /// tip
 

fastapi/applications.py

@@ -4636,6 +4636,379 @@ class FastAPI(Starlette):
             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[
+            int | None,
+            Doc(
+                """
+                The default status code to be used for the response.
+
+                You could override the status code by returning a response directly.
+
+                Read more about it in the
+                [FastAPI docs for Response Status Code](https://fastapi.tiangolo.com/tutorial/response-status-code/).
+                """
+            ),
+        ] = None,
+        tags: Annotated[
+            list[str | Enum] | None,
+            Doc(
+                """
+                A list of tags to be applied to the *path operation*.
+
+                It will be added to the generated OpenAPI (e.g. visible at `/docs`).
+
+                Read more about it in the
+                [FastAPI docs for Path Operation Configuration](https://fastapi.tiangolo.com/tutorial/path-operation-configuration/#tags).
+                """
+            ),
+        ] = None,
+        dependencies: Annotated[
+            Sequence[Depends] | None,
+            Doc(
+                """
+                A list of dependencies (using `Depends()`) to be applied to the
+                *path operation*.
+
+                Read more about it in the
+                [FastAPI docs for Dependencies in path operation decorators](https://fastapi.tiangolo.com/tutorial/dependencies/dependencies-in-path-operation-decorators/).
+                """
+            ),
+        ] = None,
+        summary: Annotated[
+            str | None,
+            Doc(
+                """
+                A summary for the *path operation*.
+
+                It will be added to the generated OpenAPI (e.g. visible at `/docs`).
+
+                Read more about it in the
+                [FastAPI docs for Path Operation Configuration](https://fastapi.tiangolo.com/tutorial/path-operation-configuration/).
+                """
+            ),
+        ] = None,
+        description: Annotated[
+            str | None,
+            Doc(
+                """
+                A description for the *path operation*.
+
+                If not provided, it will be extracted automatically from the docstring
+                of the *path operation function*.
+
+                It can contain Markdown.
+
+                It will be added to the generated OpenAPI (e.g. visible at `/docs`).
+
+                Read more about it in the
+                [FastAPI docs for Path Operation Configuration](https://fastapi.tiangolo.com/tutorial/path-operation-configuration/).
+                """
+            ),
+        ] = None,
+        response_description: Annotated[
+            str,
+            Doc(
+                """
+                The description for the default response.
+
+                It will be added to the generated OpenAPI (e.g. visible at `/docs`).
+                """
+            ),
+        ] = "Successful Response",
+        responses: Annotated[
+            dict[int | str, dict[str, Any]] | None,
+            Doc(
+                """
+                Additional responses that could be returned by this *path operation*.
+
+                It will be added to the generated OpenAPI (e.g. visible at `/docs`).
+                """
+            ),
+        ] = None,
+        deprecated: Annotated[
+            bool | None,
+            Doc(
+                """
+                Mark this *path operation* as deprecated.
+
+                It will be added to the generated OpenAPI (e.g. visible at `/docs`).
+                """
+            ),
+        ] = None,
+        operation_id: Annotated[
+            str | None,
+            Doc(
+                """
+                Custom operation ID to be used by this *path operation*.
+
+                By default, it is generated automatically.
+
+                If you provide a custom operation ID, you need to make sure it is
+                unique for the whole API.
+
+                You can customize the
+                operation ID generation with the parameter
+                `generate_unique_id_function` in the `FastAPI` class.
+
+                Read more about it in the
+                [FastAPI docs about how to Generate Clients](https://fastapi.tiangolo.com/advanced/generate-clients/#custom-generate-unique-id-function).
+                """
+            ),
+        ] = None,
+        response_model_include: Annotated[
+            IncEx | None,
+            Doc(
+                """
+                Configuration passed to Pydantic to include only certain fields in the
+                response data.
+
+                Read more about it in the
+                [FastAPI docs for Response Model - Return Type](https://fastapi.tiangolo.com/tutorial/response-model/#response_model_include-and-response_model_exclude).
+                """
+            ),
+        ] = None,
+        response_model_exclude: Annotated[
+            IncEx | None,
+            Doc(
+                """
+                Configuration passed to Pydantic to exclude certain fields in the
+                response data.
+
+                Read more about it in the
+                [FastAPI docs for Response Model - Return Type](https://fastapi.tiangolo.com/tutorial/response-model/#response_model_include-and-response_model_exclude).
+                """
+            ),
+        ] = None,
+        response_model_by_alias: Annotated[
+            bool,
+            Doc(
+                """
+                Configuration passed to Pydantic to define if the response model
+                should be serialized by alias when an alias is used.
+
+                Read more about it in the
+                [FastAPI docs for Response Model - Return Type](https://fastapi.tiangolo.com/tutorial/response-model/#response_model_include-and-response_model_exclude).
+                """
+            ),
+        ] = True,
+        response_model_exclude_unset: Annotated[
+            bool,
+            Doc(
+                """
+                Configuration passed to Pydantic to define if the response data
+                should have all the fields, including the ones that were not set and
+                have their default values. This is different from
+                `response_model_exclude_defaults` in that if the fields are set,
+                they will be included in the response, even if the value is the same
+                as the default.
+
+                When `True`, default values are omitted from the response.
+
+                Read more about it in the
+                [FastAPI docs for Response Model - Return Type](https://fastapi.tiangolo.com/tutorial/response-model/#use-the-response_model_exclude_unset-parameter).
+                """
+            ),
+        ] = False,
+        response_model_exclude_defaults: Annotated[
+            bool,
+            Doc(
+                """
+                Configuration passed to Pydantic to define if the response data
+                should have all the fields, including the ones that have the same value
+                as the default. This is different from `response_model_exclude_unset`
+                in that if the fields are set but contain the same default values,
+                they will be excluded from the response.
+
+                When `True`, default values are omitted from the response.
+
+                Read more about it in the
+                [FastAPI docs for Response Model - Return Type](https://fastapi.tiangolo.com/tutorial/response-model/#use-the-response_model_exclude_unset-parameter).
+                """
+            ),
+        ] = False,
+        response_model_exclude_none: Annotated[
+            bool,
+            Doc(
+                """
+                Configuration passed to Pydantic to define if the response data should
+                exclude fields set to `None`.
+
+                This is much simpler (less smart) than `response_model_exclude_unset`
+                and `response_model_exclude_defaults`. You probably want to use one of
+                those two instead of this one, as those allow returning `None` values
+                when it makes sense.
+
+                Read more about it in the
+                [FastAPI docs for Response Model - Return Type](https://fastapi.tiangolo.com/tutorial/response-model/#response_model_exclude_none).
+                """
+            ),
+        ] = False,
+        include_in_schema: Annotated[
+            bool,
+            Doc(
+                """
+                Include this *path operation* in the generated OpenAPI schema.
+
+                This affects the generated OpenAPI (e.g. visible at `/docs`).
+
+                Read more about it in the
+                [FastAPI docs for Query Parameters and String Validations](https://fastapi.tiangolo.com/tutorial/query-params-str-validations/#exclude-parameters-from-openapi).
+                """
+            ),
+        ] = True,
+        response_class: Annotated[
+            type[Response],
+            Doc(
+                """
+                Response class to be used for this *path operation*.
+
+                This will not be used if you return a response directly.
+
+                Read more about it in the
+                [FastAPI docs for Custom Response - HTML, Stream, File, others](https://fastapi.tiangolo.com/advanced/custom-response/#redirectresponse).
+                """
+            ),
+        ] = Default(JSONResponse),
+        name: Annotated[
+            str | None,
+            Doc(
+                """
+                Name for this *path operation*. Only used internally.
+                """
+            ),
+        ] = None,
+        callbacks: Annotated[
+            list[BaseRoute] | None,
+            Doc(
+                """
+                List of *path operations* that will be used as OpenAPI callbacks.
+
+                This is only for OpenAPI documentation, the callbacks won't be used
+                directly.
+
+                It will be added to the generated OpenAPI (e.g. visible at `/docs`).
+
+                Read more about it in the
+                [FastAPI docs for OpenAPI Callbacks](https://fastapi.tiangolo.com/advanced/openapi-callbacks/).
+                """
+            ),
+        ] = None,
+        openapi_extra: Annotated[
+            dict[str, Any] | None,
+            Doc(
+                """
+                Extra metadata to be included in the OpenAPI schema for this *path
+                operation*.
+
+                Read more about it in the
+                [FastAPI docs for Path Operation Advanced Configuration](https://fastapi.tiangolo.com/advanced/path-operation-advanced-configuration/#custom-openapi-path-operation-schema).
+                """
+            ),
+        ] = None,
+        generate_unique_id_function: Annotated[
+            Callable[[routing.APIRoute], str],
+            Doc(
+                """
+                Customize the function used to generate unique IDs for the *path
+                operations* shown in the generated OpenAPI.
+
+                This is particularly useful when automatically generating clients or
+                SDKs for your API.
+
+                Read more about it in the
+                [FastAPI docs about how to Generate Clients](https://fastapi.tiangolo.com/advanced/generate-clients/#custom-generate-unique-id-function).
+                """
+            ),
+        ] = Default(generate_unique_id),
+    ) -> Callable[[DecoratedCallable], DecoratedCallable]:
+        """
+        Add a *path operation* using an HTTP QUERY operation.
+
+        ## Example
+
+        ```python
+        from fastapi import Body, FastAPI
+
+        app = FastAPI()
+
+        @app.query("/items/")
+        def query_items(search: str = Body(embed=True)):
+            return [{"name": "Empanada"}, {"name": "Arepa"}]
+        ```
+        """
+        return self.router.query(
+            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,
+            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 websocket_route(
         self, path: str, name: str | None = None
     ) -> Callable[[DecoratedCallable], DecoratedCallable]:

fastapi/openapi/constants.py

@@ -1,3 +1,3 @@
-METHODS_WITH_BODY = {"GET", "HEAD", "POST", "PUT", "DELETE", "PATCH"}
+METHODS_WITH_BODY = {"GET", "HEAD", "POST", "PUT", "DELETE", "PATCH", "QUERY"}
 REF_PREFIX = "#/components/schemas/"
 REF_TEMPLATE = "#/components/schemas/{model}"

fastapi/routing.py

@@ -6144,6 +6144,383 @@ class APIRouter(routing.Router):
             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[
+            int | None,
+            Doc(
+                """
+                The default status code to be used for the response.
+
+                You could override the status code by returning a response directly.
+
+                Read more about it in the
+                [FastAPI docs for Response Status Code](https://fastapi.tiangolo.com/tutorial/response-status-code/).
+                """
+            ),
+        ] = None,
+        tags: Annotated[
+            list[str | Enum] | None,
+            Doc(
+                """
+                A list of tags to be applied to the *path operation*.
+
+                It will be added to the generated OpenAPI (e.g. visible at `/docs`).
+
+                Read more about it in the
+                [FastAPI docs for Path Operation Configuration](https://fastapi.tiangolo.com/tutorial/path-operation-configuration/#tags).
+                """
+            ),
+        ] = None,
+        dependencies: Annotated[
+            Sequence[params.Depends] | None,
+            Doc(
+                """
+                A list of dependencies (using `Depends()`) to be applied to the
+                *path operation*.
+
+                Read more about it in the
+                [FastAPI docs for Dependencies in path operation decorators](https://fastapi.tiangolo.com/tutorial/dependencies/dependencies-in-path-operation-decorators/).
+                """
+            ),
+        ] = None,
+        summary: Annotated[
+            str | None,
+            Doc(
+                """
+                A summary for the *path operation*.
+
+                It will be added to the generated OpenAPI (e.g. visible at `/docs`).
+
+                Read more about it in the
+                [FastAPI docs for Path Operation Configuration](https://fastapi.tiangolo.com/tutorial/path-operation-configuration/).
+                """
+            ),
+        ] = None,
+        description: Annotated[
+            str | None,
+            Doc(
+                """
+                A description for the *path operation*.
+
+                If not provided, it will be extracted automatically from the docstring
+                of the *path operation function*.
+
+                It can contain Markdown.
+
+                It will be added to the generated OpenAPI (e.g. visible at `/docs`).
+
+                Read more about it in the
+                [FastAPI docs for Path Operation Configuration](https://fastapi.tiangolo.com/tutorial/path-operation-configuration/).
+                """
+            ),
+        ] = None,
+        response_description: Annotated[
+            str,
+            Doc(
+                """
+                The description for the default response.
+
+                It will be added to the generated OpenAPI (e.g. visible at `/docs`).
+                """
+            ),
+        ] = "Successful Response",
+        responses: Annotated[
+            dict[int | str, dict[str, Any]] | None,
+            Doc(
+                """
+                Additional responses that could be returned by this *path operation*.
+
+                It will be added to the generated OpenAPI (e.g. visible at `/docs`).
+                """
+            ),
+        ] = None,
+        deprecated: Annotated[
+            bool | None,
+            Doc(
+                """
+                Mark this *path operation* as deprecated.
+
+                It will be added to the generated OpenAPI (e.g. visible at `/docs`).
+                """
+            ),
+        ] = None,
+        operation_id: Annotated[
+            str | None,
+            Doc(
+                """
+                Custom operation ID to be used by this *path operation*.
+
+                By default, it is generated automatically.
+
+                If you provide a custom operation ID, you need to make sure it is
+                unique for the whole API.
+
+                You can customize the
+                operation ID generation with the parameter
+                `generate_unique_id_function` in the `FastAPI` class.
+
+                Read more about it in the
+                [FastAPI docs about how to Generate Clients](https://fastapi.tiangolo.com/advanced/generate-clients/#custom-generate-unique-id-function).
+                """
+            ),
+        ] = None,
+        response_model_include: Annotated[
+            IncEx | None,
+            Doc(
+                """
+                Configuration passed to Pydantic to include only certain fields in the
+                response data.
+
+                Read more about it in the
+                [FastAPI docs for Response Model - Return Type](https://fastapi.tiangolo.com/tutorial/response-model/#response_model_include-and-response_model_exclude).
+                """
+            ),
+        ] = None,
+        response_model_exclude: Annotated[
+            IncEx | None,
+            Doc(
+                """
+                Configuration passed to Pydantic to exclude certain fields in the
+                response data.
+
+                Read more about it in the
+                [FastAPI docs for Response Model - Return Type](https://fastapi.tiangolo.com/tutorial/response-model/#response_model_include-and-response_model_exclude).
+                """
+            ),
+        ] = None,
+        response_model_by_alias: Annotated[
+            bool,
+            Doc(
+                """
+                Configuration passed to Pydantic to define if the response model
+                should be serialized by alias when an alias is used.
+
+                Read more about it in the
+                [FastAPI docs for Response Model - Return Type](https://fastapi.tiangolo.com/tutorial/response-model/#response_model_include-and-response_model_exclude).
+                """
+            ),
+        ] = True,
+        response_model_exclude_unset: Annotated[
+            bool,
+            Doc(
+                """
+                Configuration passed to Pydantic to define if the response data
+                should have all the fields, including the ones that were not set and
+                have their default values. This is different from
+                `response_model_exclude_defaults` in that if the fields are set,
+                they will be included in the response, even if the value is the same
+                as the default.
+
+                When `True`, default values are omitted from the response.
+
+                Read more about it in the
+                [FastAPI docs for Response Model - Return Type](https://fastapi.tiangolo.com/tutorial/response-model/#use-the-response_model_exclude_unset-parameter).
+                """
+            ),
+        ] = False,
+        response_model_exclude_defaults: Annotated[
+            bool,
+            Doc(
+                """
+                Configuration passed to Pydantic to define if the response data
+                should have all the fields, including the ones that have the same value
+                as the default. This is different from `response_model_exclude_unset`
+                in that if the fields are set but contain the same default values,
+                they will be excluded from the response.
+
+                When `True`, default values are omitted from the response.
+
+                Read more about it in the
+                [FastAPI docs for Response Model - Return Type](https://fastapi.tiangolo.com/tutorial/response-model/#use-the-response_model_exclude_unset-parameter).
+                """
+            ),
+        ] = False,
+        response_model_exclude_none: Annotated[
+            bool,
+            Doc(
+                """
+                Configuration passed to Pydantic to define if the response data should
+                exclude fields set to `None`.
+
+                This is much simpler (less smart) than `response_model_exclude_unset`
+                and `response_model_exclude_defaults`. You probably want to use one of
+                those two instead of this one, as those allow returning `None` values
+                when it makes sense.
+
+                Read more about it in the
+                [FastAPI docs for Response Model - Return Type](https://fastapi.tiangolo.com/tutorial/response-model/#response_model_exclude_none).
+                """
+            ),
+        ] = False,
+        include_in_schema: Annotated[
+            bool,
+            Doc(
+                """
+                Include this *path operation* in the generated OpenAPI schema.
+
+                This affects the generated OpenAPI (e.g. visible at `/docs`).
+
+                Read more about it in the
+                [FastAPI docs for Query Parameters and String Validations](https://fastapi.tiangolo.com/tutorial/query-params-str-validations/#exclude-parameters-from-openapi).
+                """
+            ),
+        ] = True,
+        response_class: Annotated[
+            type[Response],
+            Doc(
+                """
+                Response class to be used for this *path operation*.
+
+                This will not be used if you return a response directly.
+
+                Read more about it in the
+                [FastAPI docs for Custom Response - HTML, Stream, File, others](https://fastapi.tiangolo.com/advanced/custom-response/#redirectresponse).
+                """
+            ),
+        ] = Default(JSONResponse),
+        name: Annotated[
+            str | None,
+            Doc(
+                """
+                Name for this *path operation*. Only used internally.
+                """
+            ),
+        ] = None,
+        callbacks: Annotated[
+            list[BaseRoute] | None,
+            Doc(
+                """
+                List of *path operations* that will be used as OpenAPI callbacks.
+
+                This is only for OpenAPI documentation, the callbacks won't be used
+                directly.
+
+                It will be added to the generated OpenAPI (e.g. visible at `/docs`).
+
+                Read more about it in the
+                [FastAPI docs for OpenAPI Callbacks](https://fastapi.tiangolo.com/advanced/openapi-callbacks/).
+                """
+            ),
+        ] = None,
+        openapi_extra: Annotated[
+            dict[str, Any] | None,
+            Doc(
+                """
+                Extra metadata to be included in the OpenAPI schema for this *path
+                operation*.
+
+                Read more about it in the
+                [FastAPI docs for Path Operation Advanced Configuration](https://fastapi.tiangolo.com/advanced/path-operation-advanced-configuration/#custom-openapi-path-operation-schema).
+                """
+            ),
+        ] = None,
+        generate_unique_id_function: Annotated[
+            Callable[[APIRoute], str],
+            Doc(
+                """
+                Customize the function used to generate unique IDs for the *path
+                operations* shown in the generated OpenAPI.
+
+                This is particularly useful when automatically generating clients or
+                SDKs for your API.
+
+                Read more about it in the
+                [FastAPI docs about how to Generate Clients](https://fastapi.tiangolo.com/advanced/generate-clients/#custom-generate-unique-id-function).
+                """
+            ),
+        ] = Default(generate_unique_id),
+    ) -> Callable[[DecoratedCallable], DecoratedCallable]:
+        """
+        Add a *path operation* using an HTTP QUERY operation.
+
+        ## Example
+
+        ```python
+        from fastapi import APIRouter, Body, FastAPI
+
+        app = FastAPI()
+        router = APIRouter()
+
+        @router.query("/items/")
+        def query_items(search: str = Body(embed=True)):
+            return [{"name": "Empanada"}, {"name": "Arepa"}]
+
+        app.include_router(router)
+        ```
+        """
+        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,
+        )
+
     # TODO: remove this once the lifespan (or alternative) interface is improved
     async def _startup(self) -> None:
         """

tests/test_query_method.py

@@ -0,0 +1,327 @@
+from typing import Annotated
+
+from fastapi import APIRouter, Body, FastAPI
+from fastapi.testclient import TestClient
+from inline_snapshot import snapshot
+from pydantic import BaseModel
+
+app = FastAPI()
+
+router = APIRouter()
+
+
+class Search(BaseModel):
+    term: str
+    limit: int = 10
+
+
+@app.query("/search")
+def search(search: Search):
+    return {"term": search.term, "limit": search.limit, "via": "app"}
+
+
+@app.get("/search-multi")
+def search_multi_get(q: str = "default"):
+    return {"q": q, "via": "get"}
+
+
+@app.query("/search-multi")
+def search_multi_query(q: str = "default"):
+    return {"q": q, "via": "query"}
+
+
+@router.query("/router-search")
+def router_search(term: Annotated[str, Body(embed=True)]):
+    return {"term": term, "via": "router"}
+
+
+def added_search(term: Annotated[str, Body(embed=True)]):
+    return {"term": term, "via": "added"}
+
+
+app.add_api_route("/added-search", added_search, methods=["QUERY"])
+
+app.include_router(router)
+
+client = TestClient(app)
+
+
+def test_query_app_level():
+    response = client.request("QUERY", "/search", json={"term": "fastapi", "limit": 5})
+    assert response.status_code == 200, response.text
+    assert response.json() == {"term": "fastapi", "limit": 5, "via": "app"}
+
+
+def test_query_app_level_default_body_value():
+    response = client.request("QUERY", "/search", json={"term": "fastapi"})
+    assert response.status_code == 200, response.text
+    assert response.json() == {"term": "fastapi", "limit": 10, "via": "app"}
+
+
+def test_query_router_level():
+    response = client.request("QUERY", "/router-search", json={"term": "routed"})
+    assert response.status_code == 200, response.text
+    assert response.json() == {"term": "routed", "via": "router"}
+
+
+def test_query_via_add_api_route():
+    response = client.request("QUERY", "/added-search", json={"term": "added"})
+    assert response.status_code == 200, response.text
+    assert response.json() == {"term": "added", "via": "added"}
+
+
+def test_query_missing_body_returns_422():
+    response = client.request("QUERY", "/search", json={"limit": 5})
+    assert response.status_code == 422, response.text
+    assert response.json()["detail"][0]["loc"] == ["body", "term"]
+
+
+def test_query_wrong_method_returns_405():
+    response = client.request("POST", "/search", json={"term": "x"})
+    assert response.status_code == 405, response.text
+    assert "QUERY" in response.headers["allow"]
+
+
+def test_query_and_get_coexist_on_same_path():
+    get_response = client.get("/search-multi", params={"q": "from-get"})
+    assert get_response.status_code == 200, get_response.text
+    assert get_response.json() == {"q": "from-get", "via": "get"}
+
+    query_response = client.request(
+        "QUERY", "/search-multi", params={"q": "from-query"}
+    )
+    assert query_response.status_code == 200, query_response.text
+    assert query_response.json() == {"q": "from-query", "via": "query"}
+
+
+def test_openapi_schema():
+    response = client.get("/openapi.json")
+    assert response.status_code == 200, response.text
+    assert response.json() == snapshot(
+        {
+            "openapi": "3.1.0",
+            "info": {"title": "FastAPI", "version": "0.1.0"},
+            "paths": {
+                "/search": {
+                    "query": {
+                        "summary": "Search",
+                        "operationId": "search_search_query",
+                        "requestBody": {
+                            "required": True,
+                            "content": {
+                                "application/json": {
+                                    "schema": {"$ref": "#/components/schemas/Search"}
+                                }
+                            },
+                        },
+                        "responses": {
+                            "200": {
+                                "description": "Successful Response",
+                                "content": {"application/json": {"schema": {}}},
+                            },
+                            "422": {
+                                "description": "Validation Error",
+                                "content": {
+                                    "application/json": {
+                                        "schema": {
+                                            "$ref": "#/components/schemas/HTTPValidationError"
+                                        }
+                                    }
+                                },
+                            },
+                        },
+                    }
+                },
+                "/search-multi": {
+                    "get": {
+                        "summary": "Search Multi Get",
+                        "operationId": "search_multi_get_search_multi_get",
+                        "parameters": [
+                            {
+                                "name": "q",
+                                "in": "query",
+                                "required": False,
+                                "schema": {
+                                    "type": "string",
+                                    "default": "default",
+                                    "title": "Q",
+                                },
+                            }
+                        ],
+                        "responses": {
+                            "200": {
+                                "description": "Successful Response",
+                                "content": {"application/json": {"schema": {}}},
+                            },
+                            "422": {
+                                "description": "Validation Error",
+                                "content": {
+                                    "application/json": {
+                                        "schema": {
+                                            "$ref": "#/components/schemas/HTTPValidationError"
+                                        }
+                                    }
+                                },
+                            },
+                        },
+                    },
+                    "query": {
+                        "summary": "Search Multi Query",
+                        "operationId": "search_multi_query_search_multi_query",
+                        "parameters": [
+                            {
+                                "name": "q",
+                                "in": "query",
+                                "required": False,
+                                "schema": {
+                                    "type": "string",
+                                    "default": "default",
+                                    "title": "Q",
+                                },
+                            }
+                        ],
+                        "responses": {
+                            "200": {
+                                "description": "Successful Response",
+                                "content": {"application/json": {"schema": {}}},
+                            },
+                            "422": {
+                                "description": "Validation Error",
+                                "content": {
+                                    "application/json": {
+                                        "schema": {
+                                            "$ref": "#/components/schemas/HTTPValidationError"
+                                        }
+                                    }
+                                },
+                            },
+                        },
+                    },
+                },
+                "/added-search": {
+                    "query": {
+                        "summary": "Added Search",
+                        "operationId": "added_search_added_search_query",
+                        "requestBody": {
+                            "required": True,
+                            "content": {
+                                "application/json": {
+                                    "schema": {
+                                        "$ref": "#/components/schemas/Body_added_search_added_search_query"
+                                    }
+                                }
+                            },
+                        },
+                        "responses": {
+                            "200": {
+                                "description": "Successful Response",
+                                "content": {"application/json": {"schema": {}}},
+                            },
+                            "422": {
+                                "description": "Validation Error",
+                                "content": {
+                                    "application/json": {
+                                        "schema": {
+                                            "$ref": "#/components/schemas/HTTPValidationError"
+                                        }
+                                    }
+                                },
+                            },
+                        },
+                    }
+                },
+                "/router-search": {
+                    "query": {
+                        "summary": "Router Search",
+                        "operationId": "router_search_router_search_query",
+                        "requestBody": {
+                            "required": True,
+                            "content": {
+                                "application/json": {
+                                    "schema": {
+                                        "$ref": "#/components/schemas/Body_router_search_router_search_query"
+                                    }
+                                }
+                            },
+                        },
+                        "responses": {
+                            "200": {
+                                "description": "Successful Response",
+                                "content": {"application/json": {"schema": {}}},
+                            },
+                            "422": {
+                                "description": "Validation Error",
+                                "content": {
+                                    "application/json": {
+                                        "schema": {
+                                            "$ref": "#/components/schemas/HTTPValidationError"
+                                        }
+                                    }
+                                },
+                            },
+                        },
+                    }
+                },
+            },
+            "components": {
+                "schemas": {
+                    "Body_added_search_added_search_query": {
+                        "properties": {"term": {"type": "string", "title": "Term"}},
+                        "type": "object",
+                        "required": ["term"],
+                        "title": "Body_added_search_added_search_query",
+                    },
+                    "Body_router_search_router_search_query": {
+                        "properties": {"term": {"type": "string", "title": "Term"}},
+                        "type": "object",
+                        "required": ["term"],
+                        "title": "Body_router_search_router_search_query",
+                    },
+                    "HTTPValidationError": {
+                        "properties": {
+                            "detail": {
+                                "items": {
+                                    "$ref": "#/components/schemas/ValidationError"
+                                },
+                                "type": "array",
+                                "title": "Detail",
+                            }
+                        },
+                        "type": "object",
+                        "title": "HTTPValidationError",
+                    },
+                    "Search": {
+                        "properties": {
+                            "term": {"type": "string", "title": "Term"},
+                            "limit": {
+                                "type": "integer",
+                                "title": "Limit",
+                                "default": 10,
+                            },
+                        },
+                        "type": "object",
+                        "required": ["term"],
+                        "title": "Search",
+                    },
+                    "ValidationError": {
+                        "properties": {
+                            "loc": {
+                                "items": {
+                                    "anyOf": [{"type": "string"}, {"type": "integer"}]
+                                },
+                                "type": "array",
+                                "title": "Location",
+                            },
+                            "msg": {"type": "string", "title": "Message"},
+                            "type": {"type": "string", "title": "Error Type"},
+                            "input": {"title": "Input"},
+                            "ctx": {"type": "object", "title": "Context"},
+                        },
+                        "type": "object",
+                        "required": ["loc", "msg", "type"],
+                        "title": "ValidationError",
+                    },
+                }
+            },
+        }
+    )