This is supported since FastAPI version `0.115.0`. 🤓

///

## Header Parameters with a Pydantic Model { #header-parameters-with-a-pydantic-model }

Declare the **header parameters** that you need in a **Pydantic model**, and then declare the parameter as `Header`:

{* ../../docs_src/header_param_models/tutorial001_an_py310.py hl[9:14,18] *}

### Casos de uso: serviço externo { #use-cases-external-service }

Um exemplo pode ser que você possua um provedor de autenticação externo que você precisa chamar.

Você envia ao serviço um *token* e ele retorna um usuário autenticado.

Este provedor pode cobrar por requisição, e chamá-lo pode levar mais tempo do que se você tivesse um usuário fixo para os testes.

// It randomly fetches an IP via custom LookupHost function and dials it by the given dial
// function. LookupHost may implement an internal DNS caching implementation, lookupHost
// input if nil then net.DefaultResolver.LookupHost is used.
//
// It dials one by one and returns first connected `net.Conn`.
// If it fails to dial all IPs from cache it returns first error. If no baseDialFunc

    public boolean remove(@Nullable Object o) {
      if (o instanceof Entry) {
        Entry<?, ?> entry = (Entry<?, ?>) o;
        if (unfiltered.containsKey(entry.getKey())
            // if this holds, then we know entry.getKey() is a K
            && keyPredicate.apply((K) entry.getKey())) {
          return unfiltered.remove(entry.getKey(), entry.getValue());
        }
      }
      return false;
    }
  }

        // fall back to copying URLs to files in the testDir == null block below
      }
    }

    if (testDir == null) {
      // testdata resources aren't file:// urls, so create a directory to store them in and then
      // copy the resources to the filesystem as needed
      testDir = createTempDir();
    }

    return testDir;
  }

  /** Returns the file with the given name under the testdata directory. */

    public boolean remove(@Nullable Object o) {
      if (o instanceof Entry) {
        Entry<?, ?> entry = (Entry<?, ?>) o;
        if (unfiltered.containsKey(entry.getKey())
            // if this holds, then we know entry.getKey() is a K
            && keyPredicate.apply((K) entry.getKey())) {
          return unfiltered.remove(entry.getKey(), entry.getValue());
        }
      }
      return false;
    }
  }

   */
  @Override
  Set<V> createCollection() {
    return Platform.newHashSetWithExpectedSize(expectedValuesPerKey);
  }

  /**
   * @serialData expectedValuesPerKey, number of distinct keys, and then for each distinct key: the
   *     key, number of values for that key, and the key's values
   */
  @GwtIncompatible
  @J2ktIncompatible
    private void writeObject(ObjectOutputStream stream) throws IOException {

  }

  /**
   * Converts the specified {@code String str} from this format to the specified {@code format}. A
   * "best effort" approach is taken; if {@code str} does not conform to the assumed format, then
   * the behavior of this method is undefined but we make a reasonable effort at converting anyway.
   */
  public final String to(CaseFormat format, String str) {
    checkNotNull(format);
    checkNotNull(str);

    * Um parâmetro query.
    * Um header.
    * Um cookie.
* `http`: padrão HTTP de sistemas autenticação, incluindo:
    * `bearer`: um header de `Authorization` com valor de `Bearer` adicionado de um token. Isso é herança do OAuth2.
    * HTTP Basic authentication.
    * HTTP Digest, etc.
* `oauth2`: todas as formas do OAuth2 para lidar com segurança (chamados "fluxos").

java.net.InetAddress#getHostAddress()
java.net.Inet4Address#getHostAddress()
java.net.Inet6Address#getHostAddress()
java.net.InetSocketAddress#toString()

@defaultMessage avoid DNS lookups by accident: if you have a valid reason, then @SuppressWarnings with that reason so its completely clear
java.net.InetAddress#getHostName()
java.net.InetAddress#getCanonicalHostName()