Events
======

Events allow you to capture metrics on your application’s HTTP calls. Use events to monitor:

 * The size and frequency of the HTTP calls your application makes. If you’re making too many calls, or your calls are too large, you should know about it!
 * The performance of these calls on the underlying network. If the network’s performance isn’t sufficient, you need to either improve the network or use less of it.

### EventListener

# Declare Request Example Data { #declare-request-example-data }

You can declare examples of the data your app can receive.

Here are several ways to do it.

## Extra JSON Schema data in Pydantic models { #extra-json-schema-data-in-pydantic-models }

You can declare `examples` for a Pydantic model that will be added to the generated JSON Schema.

//// tab | Pydantic v2

{* ../../docs_src/schema_extra_example/tutorial001_py310.py hl[13:24] *}

However, further setup is required to run tests or programs directly on a device.

First make sure you have a valid developer certificate and have setup your device properly
to run apps signed by your developer certificate. Then install the libimobiledevice and
ideviceinstaller tools from https://www.libimobiledevice.org/. Use the HEAD versions from

# Deploy FastAPI on Cloud Providers { #deploy-fastapi-on-cloud-providers }

You can use virtually **any cloud provider** to deploy your FastAPI application.

In most of the cases, the main cloud providers have guides to deploy FastAPI with them.

## Cloud Providers - Sponsors { #cloud-providers-sponsors }

 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

  }

  /**
   * Returns the empty immutable list. This list behaves and performs comparably to {@link
   * Collections#emptyList}, and is preferable mainly for consistency and maintainability of your
   * code.
   *
   * <p><b>Performance note:</b> the instance returned is a singleton.
   */
  // Casting to any type is safe because the list will never hold any elements.
  @SuppressWarnings("unchecked")

/// info | Informação

Se você estiver usando contêineres, por exemplo com Docker ou Kubernetes, falarei mais sobre isso no próximo capítulo: [FastAPI em contêineres - Docker](docker.md){.internal-link target=_blank}.

Em particular, ao executar no **Kubernetes** você provavelmente **não** vai querer usar vários trabalhadores e, em vez disso, executar **um único processo Uvicorn por contêiner**, mas falarei sobre isso mais adiante neste capítulo.

///

  // We need to test that our method behaves like the JDK method.
  @SuppressWarnings("InlineMeInliner")
  public void testHashCode() {
    for (float value : VALUES) {
      assertThat(Floats.hashCode(value)).isEqualTo(Float.hashCode(value));
    }
  }

  @SuppressWarnings("InlineMeInliner") // We need to test our method.
  public void testIsFinite() {
    for (float value : NUMBERS) {

  // We need to test that our method behaves like the JDK method.
  @SuppressWarnings("InlineMeInliner")
  public void testHashCode() {
    for (float value : VALUES) {
      assertThat(Floats.hashCode(value)).isEqualTo(Float.hashCode(value));
    }
  }

  @SuppressWarnings("InlineMeInliner") // We need to test our method.
  public void testIsFinite() {
    for (float value : NUMBERS) {

# Depuração

Você pode conectar o depurador no seu editor, por exemplo, com o Visual Studio Code ou PyCharm.

## Chamar `uvicorn`

Em seu aplicativo FastAPI, importe e execute `uvicorn` diretamente:

{* ../../docs_src/debugging/tutorial001.py hl[1,15] *}

### Sobre `__name__ == "__main__"`

O objetivo principal de `__name__ == "__main__"` é ter algum código que seja executado quando seu arquivo for chamado com:

<div class="termy">