In this section you will see how.

## The normal process { #the-normal-process }

The normal (default) process, is as follows.

A `FastAPI` application (instance) has an `.openapi()` method that is expected to return the OpenAPI schema.

As part of the application object creation, a *path operation* for `/openapi.json` (or for whatever you set your `openapi_url`) is registered.

{* ../../docs_src/behind_a_proxy/tutorial004_py39.py hl[9] *}

and then it won't include it in the OpenAPI schema.

## Mounting a sub-application { #mounting-a-sub-application }

If you need to mount a sub-application (as described in [Sub Applications - Mounts](sub-applications.md){.internal-link target=_blank}) while also using a proxy with `root_path`, you can do it normally, as you would expect.

/// warning | Atenção

Você pode declarar vários parâmetros `Form` em uma *operação de rota*, mas não pode declarar campos `Body` que espera receber como JSON, pois a requisição terá o corpo codificado usando `application/x-www-form-urlencoded` em vez de `application/json`.

Isso não é uma limitação do **FastAPI**, é parte do protocolo HTTP.

///

## Recapitulando { #recap }

                    "responses": {
                        "200": {
                            "description": "The created item",
                            "content": {
                                "application/json": {
                                    "schema": {"$ref": "#/components/schemas/Item"}
                                }
                            },
                        },
                        "422": {

                            "description": "Successful Response",
                            "content": {"application/json": {"schema": {}}},
                        },
                        "422": {
                            "description": "Validation Error",
                            "content": {
                                "application/json": {
                                    "schema": {

                                "content": {"application/json": {"schema": {}}},
                            },
                            "422": {
                                "description": "Validation Error",
                                "content": {
                                    "application/json": {
                                        "schema": {

    /**
     * Converts a string into <code>application/x-www-form-urlencoded</code>
     * format using the specified encoding scheme.
     *
     * @param s
     *            The string to be converted. Must not be {@literal null} or empty.
     * @param enc
     *            The encoding scheme. Must not be {@literal null} or empty.
     * @return The string encoded in <code>application/x-www-form-urlencoded</code> format.
     */

	// Some standard content-types which we strictly dis-allow for compression.
	standardExcludeCompressContentTypes = []string{"video/*", "audio/*", "application/zip", "application/x-gzip", "application/x-zip-compressed", " application/x-compress", "application/x-spoon"}

	// AuthZ Plugin system.
	globalAuthZPlugin *polplugin.AuthZPlugin

	// Deployment ID - unique per deployment

                "responses": {
                    "200": {
                        "content": {"application/json": {"schema": {}}},
                        "description": "Successful Response",
                    },
                    "422": {
                        "content": {
                            "application/json": {
                                "schema": {

                        "200": {
                            "content": {"application/json": {"schema": {}}},
                            "description": "Successful Response",
                        },
                        "422": {
                            "content": {
                                "application/json": {
                                    "schema": {