You need to import `WSGIMiddleware`.

Then wrap the WSGI (e.g. Flask) app with the middleware.

And then mount that under a path.

{* ../../docs_src/wsgi/tutorial001_py39.py hl[2:3,3] *}

## Check it { #check-it }

Now, every request under the path `/v1/` will be handled by the Flask application.

And the rest will be handled by **FastAPI**.

En esos casos, puedes usar el parámetro del decorador de path operation `response_model` en lugar del tipo de retorno.

Puedes usar el parámetro `response_model` en cualquiera de las *path operations*:

* `@app.get()`
* `@app.post()`
* `@app.put()`
* `@app.delete()`
* etc.

            Files.walk(tempDir)
                    .sorted((a, b) -> b.compareTo(a)) // Delete files before directories
                    .forEach(path -> {
                        try {
                            Files.delete(path);
                        } catch (IOException e) {
                            // Ignore cleanup errors
                        }
                    });
        }
    }

    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "openapi": "3.1.0",
        "info": {"title": "FastAPI", "version": "0.1.0"},
        "paths": {
            "/items/": {
                "get": {
                    "responses": {
                        "200": {
                            "description": "Successful Response",

    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "openapi": "3.1.0",
        "info": {"title": "FastAPI", "version": "0.1.0"},
        "paths": {
            "/users/me": {
                "get": {
                    "responses": {
                        "200": {
                            "description": "Successful Response",

    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "openapi": "3.1.0",
        "info": {"title": "FastAPI", "version": "0.1.0"},
        "paths": {
            "/users/me": {
                "get": {
                    "responses": {
                        "200": {
                            "description": "Successful Response",

    //                                                                          Definition
    //                                                                          ==========
    public static final String PATH = "es_status.dfmail";

    // ===================================================================================
    //                                                                         Entry Point

import os
import shutil

from fastapi.testclient import TestClient


def test_main():
    if os.path.isdir("./static"):  # pragma: nocover
        shutil.rmtree("./static")
    if os.path.isdir("./templates"):  # pragma: nocover
        shutil.rmtree("./templates")
    shutil.copytree("./docs_src/templates/templates/", "./templates")
    shutil.copytree("./docs_src/templates/static/", "./static")

* «the SQLModel docs»: «die SQLModel-Dokumentation»
* «the docs»: «die Dokumentation» (use singular case)
* «the env var»: «die Umgebungsvariable»
* «the `PATH` environment variable»: «die `PATH`-Umgebungsvariable»
* «the `PATH`»: «der `PATH`»
* «the `requirements.txt`»: «die `requirements.txt`»
* «the API Router»: «der API-Router»
* «the Authorization-Header»: «der Autorisierungsheader»

///

This parameter doesn't create that endpoint / *path operation*, but declares that the URL `/token` will be the one that the client should use to get the token. That information is used in OpenAPI, and then in the interactive API documentation systems.

We will soon also create the actual path operation.

/// info