Let's start with a simple FastAPI application:

{* ../../docs_src/generate_clients/tutorial001_py39.py hl[7:9,12:13,16:17,21] *}

Notice that the *path operations* define the models they use for request payload and response payload, using the models `Item` and `ResponseMessage`.

### API Docs { #api-docs }

If you go to `/docs`, you will see that it has the **schemas** for the data to be sent in requests and received in responses:

```console
$ uvicorn main:app --reload

INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
INFO:     Started reloader process [28720]
INFO:     Started server process [28722]
INFO:     Waiting for application startup.
INFO:     Application startup complete.
```

</div>

<details markdown="1">
<summary><code>uvicorn main:app --reload</code>コマンドについて</summary>

```

</div>

<details markdown="1">
<summary>Was macht der Befehl <code>uvicorn main:app --reload</code> ...</summary>

Der Befehl `uvicorn main:app` bezieht sich auf:

* `main`: die Datei `main.py` (das Python-„Modul“).
* `app`: das Objekt, das innerhalb von `main.py` mit der Zeile `app = FastAPI()` erzeugt wurde.
* `--reload`: lässt den Server nach Codeänderungen neu starten. Tun Sie das nur während der Entwicklung.

</details>

```

</div>

<details markdown="1">
<summary>Informazioni sul comando <code>uvicorn main:app --reload</code>...</summary>

Vediamo il comando `uvicorn main:app` in dettaglio:

* `main`: il file `main.py` (il "modulo" Python).
* `app`: l'oggetto creato dentro `main.py` con la riga di codice `app = FastAPI()`.
* `--reload`: ricarica il server se vengono rilevati cambiamenti del codice. Usalo solo durante la fase di sviluppo.

// The remaining payload and versions are returned.
func checkXL2V1(buf []byte) (payload []byte, major, minor uint16, e error) {
	if len(buf) <= 8 {
		return payload, 0, 0, fmt.Errorf("xlMeta: no data")
	}

	if !bytes.Equal(buf[:4], xlHeader[:]) {
		return payload, 0, 0, fmt.Errorf("xlMeta: unknown XLv2 header, expected %v, got %v", xlHeader[:4], buf[:4])
	}

        // Arrange
        byte[] payload = new byte[] { 5, 6 };

        // Act
        spyBlob.set(payload);

        // Assert
        verify(spyBlob, times(1)).set(payload);
        assertSame(payload, spyBlob.get(), "Spy should behave like real object exposing same array");
        assertEquals(2, spyBlob.length(), "length() should reflect the set payload length");
    }

```console
$ uvicorn main:app --reload

INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
INFO:     Started reloader process [28720]
INFO:     Started server process [28722]
INFO:     Waiting for application startup.
INFO:     Application startup complete.
```

</div>

<details markdown="1">
<summary><code>uvicorn main:app --reload</code> 명령에 관하여...</summary>

		// Test case with "X-Amz-Content-Sha256" not set so we can skip.
		{"", "", "", "", true},

		// Test case - 3.
		// Test case with "X-Amz-Content-Sha256" header set to  "UNSIGNED-PAYLOAD"
		// When "X-Amz-Content-Sha256" header is set to  "UNSIGNED-PAYLOAD", validation of content sha256 has to be skipped.
		{"X-Amz-Content-Sha256", unsignedPayload, "X-Amz-Credential", "", true},

		// Test case - 4.

{* ../../docs_src/sub_applications/tutorial001.py hl[11, 19] *}

### 자동으로 생성된 API 문서 확인

이제, `uvicorn`으로 메인 응용프로그램을 실행하십시오. 당신의 파일이 `main.py`라면, 이렇게 실행합니다:

<div class="termy">

```console
$ uvicorn main:app --reload

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

          message == "Plaintext before ENCRYPTION" || message == "Plaintext after DECRYPTION" -> Type.Plaintext
          message.startsWith("System property ") -> Type.Setup
          message.startsWith("Reload ") -> Type.Setup
          message == "No session to resume." -> Type.Handshake
          message.startsWith("Consuming ") -> Type.Handshake
          message.startsWith("Produced ") -> Type.Handshake