Also fügen wir sie in ihr eigenes `dependencies`-Modul (`app/dependencies.py`) ein.

Wir werden nun eine einfache Abhängigkeit verwenden, um einen benutzerdefinierten `X-Token`-Header zu lesen:

//// tab | Python 3.9+

```Python hl_lines="3  6-8" title="app/dependencies.py"
{!> ../../docs_src/bigger_applications/app_an_py39/dependencies.py!}
```

////

//// tab | Python 3.8+

    * JSON.
    * <abbr title="Yol: Path">Yol</abbr> parametrləri.
    * <abbr title="Sorğu: Query">Sorğu</abbr> parametrləri.
    * <abbr title="Çərəz: Cookie">Çərəzlər</abbr>.
    * <abbr title="Başlıq: Header">Başlıqlaq</abbr>.
    * <abbr title="Forma: Form">Formalar</abbr>.
    * Fayllar.

* **Soporte en el editor**.
* **Type checks**.

...y **FastAPI** usa las mismas declaraciones para:

* **Definir requerimientos**: desde request path parameters, query parameters, headers, bodies, dependencies, etc.
* **Convertir datos**: desde el request al tipo requerido.
* **Validar datos**: viniendo de cada request:
    * Generando **errores automáticos** devueltos al cliente cuando los datos son inválidos.

* HTTP Basic.
* **OAuth2** (também com **tokens JWT**). Confira o tutorial em [OAuth2 com JWT](tutorial/security/oauth2-jwt.md){.internal-link target=_blank}.
* Chaves de API em:
    * Headers.
    * parâmetros da Query.
    * Cookies etc.

Além disso, todos os recursos de seguranças do Starlette (incluindo **cookies de sessão**).

    val c = this[i]
    // The WHATWG Host parsing rules accepts some character codes which are invalid by
    // definition for OkHttp's host header checks (and the WHATWG Host syntax definition). Here
    // we rule out characters that would cause problems in host headers.
    if (c <= '\u001f' || c >= '\u007f') {
      return true
    }
    // Check for the characters mentioned in the WHATWG Host parsing spec:

		header, zerr := zip.FileInfoHeader(dummyFileInfo{
			name:    filename,
			size:    int64(sz),
			mode:    0o600,
			modTime: time.Now(),
			isDir:   false,
			sys:     nil,
		})
		if zerr != nil {
			adminLogIf(ctx, zerr)
			return nil
		}
		header.Method = zip.Deflate
		zwriter, zerr := zipWriter.CreateHeader(header)
		if zerr != nil {

lc(.25rem - 1px);border-bottom-left-radius:calc(.25rem - 1px)}.card>.card-header+.list-group,.card>.list-group+.card-footer{border-top:0}.card-body{-ms-flex:1 1 auto;flex:1 1 auto;min-height:1px;padding:1.25rem}.card-title{margin-bottom:.75rem}.card-subtitle{margin-top:-.375rem;margin-bottom:0}.card-text:last-child{margin-bottom:0}.card-link:hover{text-decoration:none}.card-link+.card-link{margin-left:1.25rem}.card-header{padding:.75rem 1.25rem;margin-bottom:0;background-color:rgba(0,0,0,.03);border-bottom:1px...

" "+Q);if(0===o&&0===i)t.css({bottom:a.footer,top:a.header}),r.css("height",a.window-(a.header+a.footer));else if(i<=a.footer)if(!1===s){var d=a.header-o;t.css("bottom",a.footer-i).css("top",d>=0?d:0),r.css("height",a.window-(a.footer-i))}else t.css("bottom",a.footer);else o<=a.header?!1===l?(t.css("top",a.header-o),r.css("height",a.window-(a.header-o))):t.css("top",a.header):!1===l?(t.css("top",0),r.css("height",a.window)):t.css("top",a.header);s&&l?(r.css("height","100%"),t.css("height","")):(...

        @SuppressWarnings("resource")
        final CsvReader csvReader = new CsvReader(reader, cfg);
        try {
            List<String> list;
            csvReader.readValues(); // ignore header
            while ((list = csvReader.readValues()) != null) {
                final String suggestWord = getValue(list, 0);
                if (StringUtil.isBlank(suggestWord)) {
                    // skip

    * JSON.
    * Path parameters.
    * Query parameters.
    * Cookies.
    * Headers.
    * Forms.
    * Files.
* <abbr title="also known as: serialization, parsing, marshalling">Conversion</abbr> of output data: converting from Python data and types to network data (as JSON):