### Aplicación de nivel superior { #top-level-application }

Primero, crea la aplicación principal de nivel superior de **FastAPI**, y sus *path operations*:

{* ../../docs_src/sub_applications/tutorial001_py39.py hl[3, 6:8] *}

### Sub-aplicación { #sub-application }

Luego, crea tu sub-aplicación, y sus *path operations*.

### Приложение верхнего уровня { #top-level-application }

Сначала создайте основное, верхнего уровня, приложение **FastAPI** и его *операции пути*:

{* ../../docs_src/sub_applications/tutorial001_py39.py hl[3, 6:8] *}

### Подприложение { #sub-application }

Затем создайте подприложение и его *операции пути*.

### Hauptanwendung { #top-level-application }

Erstellen Sie zunächst die Hauptanwendung **FastAPI** und deren *Pfadoperationen*:

{* ../../docs_src/sub_applications/tutorial001_py39.py hl[3, 6:8] *}

### Unteranwendung { #sub-application }

Erstellen Sie dann Ihre Unteranwendung und deren *Pfadoperationen*.

### Top-level application { #top-level-application }

First, create the main, top-level, **FastAPI** application, and its *path operations*:

{* ../../docs_src/sub_applications/tutorial001_py39.py hl[3, 6:8] *}

### Sub-application { #sub-application }

Then, create your sub-application, and its *path operations*.

# Bigger Applications - Multiple Files { #bigger-applications-multiple-files }

If you are building an application or a web API, it's rarely the case that you can put everything in a single file.

**FastAPI** provides a convenience tool to structure your application while keeping all the flexibility.

/// info

If you come from Flask, this would be the equivalent of Flask's Blueprints.

///

## An example file structure { #an-example-file-structure }

### Aplicação de nível superior { #top-level-application }

Primeiro, crie a aplicação principal, de nível superior, **FastAPI**, e suas *operações de rota*:

{* ../../docs_src/sub_applications/tutorial001_py39.py hl[3, 6:8] *}

### Sub-aplicação { #sub-application }

Em seguida, crie sua sub-aplicação e suas *operações de rota*.

Including how to handle lifespan state that can be used in other areas of your code.

///

## Sub Applications { #sub-applications }

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

## HTTPX { #httpx }

Even if your **FastAPI** application uses normal `def` functions instead of `async def`, it is still an `async` application underneath.

    * Will have the best performance, as it doesn't have much extra code apart from the server itself.
    * You wouldn't write an application in Uvicorn directly. That would mean that your code would have to include more or less, at least, all the code provided by Starlette (or **FastAPI**). And if you did that, your final application would have the same overhead as having used a framework and minimizing your app code and bugs.