# First Steps { #first-steps }

The simplest FastAPI file could look like this:

{* ../../docs_src/first_steps/tutorial001_py39.py *}

Copy that to a file `main.py`.

Run the live server:

<div class="termy">

```console
$ <font color="#4E9A06">fastapi</font> dev <u style="text-decoration-style:solid">main.py</u>

  <span style="background-color:#009485"><font color="#D3D7CF"> FastAPI </font></span>  Starting development server 🚀

.Release.Namespace | quote }} labels: app: {{ template "minio.name" . }}-make-bucket-job chart: {{ template "minio.chart" . }} release: {{ .Release.Name }} heritage: {{ .Release.Service }} annotations: "helm.sh/hook": post-install,post-upgrade "helm.sh/hook-delete-policy": hook-succeeded,before-hook-creation {{- with .Values.makeBucketJob.annotations }} {{ toYaml . | indent 4 }} {{- end }} spec: template: metadata: labels: app: {{ template "minio.name" . }}-job release: {{ .Release.Name }} {{- if .Values.podLabels...

.Release.Namespace | quote }} labels: app: {{ template "minio.name" . }}-make-bucket-job chart: {{ template "minio.chart" . }} release: {{ .Release.Name }} heritage: {{ .Release.Service }} annotations: "helm.sh/hook": post-install,post-upgrade "helm.sh/hook-delete-policy": hook-succeeded,before-hook-creation {{- with .Values.makeBucketJob.annotations }} {{ toYaml . | indent 4 }} {{- end }} spec: template: metadata: labels: app: {{ template "minio.name" . }}-job release: {{ .Release.Name }} {{- if .Values.podLabels...

.Release.Namespace | quote }} labels: app: {{ template "minio.name" . }}-make-bucket-job chart: {{ template "minio.chart" . }} release: {{ .Release.Name }} heritage: {{ .Release.Service }} annotations: "helm.sh/hook": post-install,post-upgrade "helm.sh/hook-delete-policy": hook-succeeded,before-hook-creation {{- with .Values.makeBucketJob.annotations }} {{ toYaml . | indent 4 }} {{- end }} spec: template: metadata: labels: app: {{ template "minio.name" . }}-job release: {{ .Release.Name }} {{- if .Values.podLabels...

.Release.Namespace | quote }} labels: app: {{ template "minio.name" . }}-make-bucket-job chart: {{ template "minio.chart" . }} release: {{ .Release.Name }} heritage: {{ .Release.Service }} annotations: "helm.sh/hook": post-install,post-upgrade "helm.sh/hook-delete-policy": hook-succeeded,before-hook-creation {{- with .Values.makeBucketJob.annotations }} {{ toYaml . | indent 4 }} {{- end }} spec: template: metadata: labels: app: {{ template "minio.name" . }}-job release: {{ .Release.Name }} {{- if .Values.podLabels...

Наприклад, якщо клієнт спробує надіслати query параметр `tool` зі значенням `plumbus`, як у цьому запиті:

```http
https://example.com/items/?limit=10&tool=plumbus
```

Він отримає відповідь з **помилкою**, яка повідомить, що query параметр `tool ` не дозволено:

```json
{
    "detail": [
        {
            "type": "extra_forbidden",
            "loc": ["query", "tool"],
            "msg": "Extra inputs are not permitted",

			Manager: &User{
				Name: "Alexis Manager",
				Tools: []Tools{
					{Name: "Alexis Tool 1"},
					{Name: "Alexis Tool 2"},
				},
			},
		},
		{
			Name: "TestMergeNestedPreloadWithNestedJoin-2",
			Manager: &User{
				Name: "Jinzhu Manager",
				Tools: []Tools{
					{Name: "Jinzhu Tool 1"},
					{Name: "Jinzhu Tool 2"},
				},
			},
		},
	}

	DB.Create(&users)

      threshold = buffer[k - 1];
    }
    // Up to bufferSize, all elements of buffer are real Ts (not null unless T includes null)
    T[] topK = Arrays.copyOf(castBuffer, bufferSize);
    // we have to support null elements, so no ImmutableList for us
    return unmodifiableList(asList(topK));
  }

もしクライアントが**クエリパラメータ**として**余分な**データを送ろうとすると、**エラー**レスポンスが返されます。

例えば、クライアントがクエリパラメータ `tool` に、値 `plumbus` を設定して送ろうとすると:

```http
https://example.com/items/?limit=10&tool=plumbus
```

クエリパラメータ `tool` が許可されていないことを通知する**エラー**レスポンスが返されます。

```json
{
    "detail": [
        {
            "type": "extra_forbidden",
            "loc": ["query", "tool"],
            "msg": "Extra inputs are not permitted",

   * <<<{{{./apidocs/org/apache/maven/api/cli/mvnenc/package-summary.html}mvnenc}}>>>, the Maven Password Encryption tool,

   * <<<{{{./apidocs/org/apache/maven/api/cli/mvnsh/package-summary.html}mvnsh}}>>>, the Maven Shell tool,

   * <<<{{{./apidocs/org/apache/maven/api/cli/mvnup/package-summary.html}mvnup}}>>>, the Maven Upgrade tool.