* Transparent GZIP shrinks download sizes.
 * Response caching avoids the network completely for repeat requests.

OkHttp perseveres when the network is troublesome: it will silently recover from common connection
problems. If your service has multiple IP addresses, OkHttp will attempt alternate addresses if the
first connect fails. This is necessary for IPv4+IPv6 and services hosted in redundant data

# OpenAPI Callbacks { #openapi-callbacks }

You could create an API with a *path operation* that could trigger a request to an *external API* created by someone else (probably the same developer that would be *using* your API).

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
<span style="color: green;">INFO</span>:     Started reloader process [28720]
<span style="color: green;">INFO</span>:     Started server process [28722]
<span style="color: green;">INFO</span>:     Waiting for application startup.
<span style="color: green;">INFO</span>:     Application startup complete.
```

</div>

     * Attempts to obtain login credentials using SPNEGO authentication.
     *
     * This method processes the HTTP request to extract and validate SPNEGO
     * authentication tokens. It handles the SPNEGO handshake process and
     * extracts the user principal from successful authentication.
     *
     * @return The login credential containing the authenticated username,

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
<span style="color: green;">INFO</span>:     Started reloader process [28720]
<span style="color: green;">INFO</span>:     Started server process [28722]
<span style="color: green;">INFO</span>:     Waiting for application startup.
<span style="color: green;">INFO</span>:     Application startup complete.
```

</div>

/// tip | Tipp

Auch die Integration anderer Authentifizierungs-/Autorisierungsanbieter wie Google, Facebook, X (Twitter), GitHub, usw. ist möglich und relativ einfach.

Das komplexeste Problem besteht darin, einen Authentifizierungs-/Autorisierungsanbieter wie solche aufzubauen, aber **FastAPI** reicht Ihnen die Tools, das einfach zu erledigen, während Ihnen die schwere Arbeit abgenommen wird.

///

                || exception.getMessage().toLowerCase().contains("used") || exception.getMessage().toLowerCase().contains("being used")
                || exception.getMessage().toLowerCase().contains("process"));
    }

    @Test
    @DisplayName("Should handle DOS error codes")
    void testDOSErrorCodes() {
        // Given
        int dosError = 0x00020002; // File not found from DOS_ERROR_CODES

/// tip

Integrating other authentication/authorization providers like Google, Facebook, X (Twitter), GitHub, etc. is also possible and relatively easy.

The most complex problem is building an authentication/authorization provider like those, but **FastAPI** gives you the tools to do it easily, while doing the heavy lifting for you.

///

## **FastAPI** utilities { #fastapi-utilities }

   * we've chosen to instead use a signature that benefits existing users -- and is still safe.
   *
   * For convertAll, I haven't looked as closely at *how* much existing users benefit, so we should
   * keep an eye out for problems that new users encounter. Note also that convertAll could support
   * both use cases by using @PolyNull. (By contrast, we can't use @PolyNull for our superinterface

   * response code like 404 or 500.
   *
   * @throws IOException if the request could not be executed due to cancellation, a connectivity
   *     problem or timeout. Because networks can fail during an exchange, it is possible that the
   *     remote server accepted the request before the failure.
   * @throws IllegalStateException when the call has already been executed.
   */