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

```Python hl_lines="3  6-8"
{!../../../docs_src/sub_applications/tutorial001.py!}
```

### Sub-application

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

This sub-application is just another standard FastAPI application, but this is the one that will be "mounted":

```Python hl_lines="11  14-16"

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    * 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.

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

## Sub Applications

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            "content": {
                "application/json": {
                    "schema": {
                        "$ref": "#/components/schemas/Message"
                    }
                }
            }
        },
        "200": {
            "description": "Successful Response",
            "content": {
                "application/json": {
                    "schema": {

 | `mov` | (MOV)       |

- Content-Types

 | `video/*`                |
 | `audio/*`                |
 | `application/zip`        |
 | `application/x-gzip`     |
 | `application/zip`        |
 | `application/x-bz2`      |
 | `application/x-compress` |
 | `application/x-xz`       |

All files with these extensions and mime types are excluded from compression,
even if compression is enabled for all types.

## Separating tests

In a real application, you probably would have your tests in a different file.

And your **FastAPI** application might also be composed of several files/modules, etc.

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        return request(Method.GET, path).header("Content-Type", "application/json");
    }

    public CurlRequest post(final String path) {
        return request(Method.POST, path).header("Content-Type", "application/json");
    }

    public CurlRequest put(final String path) {
        return request(Method.PUT, path).header("Content-Type", "application/json");
    }

    public CurlRequest delete(final String path) {