{!../../docs_src/bigger_applications/app/routers/items.py!}
```

/// tip

👉 🏁 ➡ 🛠️ 🔜 ✔️ 🌀 🔖: `["items", "custom"]`.

 & ⚫️ 🔜 ✔️ 👯‍♂️ 📨 🧾, 1️⃣ `404` & 1️⃣ `403`.

///

## 👑 `FastAPI`

🔜, ➡️ 👀 🕹 `app/main.py`.

📥 🌐❔ 👆 🗄 & ⚙️ 🎓 `FastAPI`.

👉 🔜 👑 📁 👆 🈸 👈 👔 🌐 👯‍♂️.

& 🏆 👆 ⚛ 🔜 🔜 🖖 🚮 👍 🎯 🕹, 👑 📁 🔜 🙅.

```

/// tip

This last path operation will have the combination of tags: `["items", "custom"]`.

And it will also have both responses in the documentation, one for `404` and one for `403`.

///

## The main `FastAPI`

Now, let's see the module at `app/main.py`.

Here's where you import and use the class `FastAPI`.

```

/// tip | "Tipp"

Diese letzte Pfadoperation wird eine Kombination von Tags haben: `["items", "custom"]`.

Und sie wird auch beide Responses in der Dokumentation haben, eine für `404` und eine für `403`.

///

## Das Haupt-`FastAPI`.

Sehen wir uns nun das Modul unter `app/main.py` an.

Hier importieren und verwenden Sie die Klasse `FastAPI`.

```

/// tip | "Dica"

Esta última operação de caminho terá a combinação de tags: `["items", "custom"]`.

E também terá ambas as respostas na documentação, uma para `404` e uma para `403`.

///

## O principal `FastAPI`

Agora, vamos ver o módulo em `app/main.py`.

Aqui é onde você importa e usa a classe `FastAPI`.

Este será o arquivo principal em seu aplicativo que une tudo.

    maintainers:
    - email: ******@****.***
      name: MinIO, Inc
    name: minio
    sources:
    - https://github.com/minio/minio
    urls:
    - https://charts.min.io/helm-releases/minio-4.0.3.tgz
    version: 4.0.3
  - apiVersion: v1
    appVersion: RELEASE.2022-05-08T23-50-31Z
    created: "2024-10-11T14:15:09.760342676+02:00"
    description: Multi-Cloud Object Storage

```Python hl_lines="30-31" title="app/routers/items.py"
{!../../docs_src/bigger_applications/app/routers/items.py!}
```

/// tip

最后的这个路径操作将包含标签的组合：`["items"，"custom"]`。

并且在文档中也会有两个响应，一个用于 `404`，一个用于 `403`。

///

## `FastAPI` 主体

现在，让我们来看看位于 `app/main.py` 的模块。

在这里你导入并使用 `FastAPI` 类。

这将是你的应用程序中将所有内容联结在一起的主文件。

并且由于你的大部分逻辑现在都存在于其自己的特定模块中，因此主文件的内容将非常简单。

### 导入 `FastAPI`

			//   on the bucket, Amazon S3 will return an
			//   HTTP status code 404 ("no such key")
			//   error.
			// * if you don’t have the s3:ListBucket
			//   permission, Amazon S3 will return an HTTP
			//   status code 403 ("access denied") error.`
			if globalPolicySys.IsAllowed(policy.BucketPolicyArgs{
				Action:          policy.ListBucketAction,
				BucketName:      bucket,

// The operation returns a 200 OK if the bucket exists and you
// have permission to access it. Otherwise, the operation might
// return responses such as 404 Not Found and 403 Forbidden.
func (api objectAPIHandlers) HeadBucketHandler(w http.ResponseWriter, r *http.Request) {
	ctx := newContext(r, w, "HeadBucket")

	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))

			expectedRespStatus: http.StatusNoContent,
		},
		// Test case - 3.
		// Setting Invalid AccessKey to force signature check inside the handler to fail.
		// Should return HTTP response status 403 forbidden.
		{
			bucketName: bucketName,
			objectName: objectName,
			accessKey:  "Invalid-AccessKey",
			secretKey:  credentials.SecretKey,

			expectedRespStatus: http.StatusForbidden,
		},