The process that happens when your API app calls the *external API* is named a "callback". Because the software that the external developer wrote sends a request to your API and then your API *calls back*, sending a request to an *external API* (that was probably created by the same developer).

/// tip

The *path operation* for `swagger_ui_redirect` is a helper for when you use OAuth2.

If you integrate your API with an OAuth2 provider, you will be able to authenticate and come back to the API docs with the acquired credentials. And interact with it using the real OAuth2 authentication.

Swagger UI will handle it behind the scenes for you, but it needs this "redirect" helper.

///

       * Unsafe on modern JVMs (if perhaps not quite as fast as VarHandle?). However, I'm not sure
       * exactly what we've benchmarked, and we certainly haven't benchmarked as far back as JDK 8.
       * (We also haven't benchmarked under Android. We continue to use UnsafeAtomicHelper there so
       * that we don't change the performance there, for better or for worse.) Fortunately, JVM

Each section gradually builds on the previous ones, but it's structured to separate topics, so that you can go directly to any specific one to solve your specific API needs.

It is also built to work as a future reference so you can come back and see exactly what you need.

## Run the code { #run-the-code }

All the code blocks can be copied and used directly (they are actually tested Python files).

metadata changes to source object version. If active-active replication is configured, any incoming uploads and metadata changes to versions created on the target, will sync back to the source and be marked as `REPLICA` on the source. AWS, as well as MinIO do not by default sync metadata changes on a object version marked `REPLICA` back to source. This requires a setting in the replication configuration called [replica modification sync](https://aws.amazon.com/about-aws/whats-new/2020/12/amazon-s3-rep...

**decrypted HTTP requests** to the actual HTTP application running in the same server (the **FastAPI** application, in this case), take the **HTTP response** from the application, **encrypt it** using the appropriate **HTTPS certificate** and sending it back to the client using **HTTPS**. This server is often called a **<a href="https://en.wikipedia.org/wiki/TLS_termination_proxy" class="external-link" target="_blank">TLS Termination Proxy</a>**.

Some of the options you could use as a TLS Termination...

  /**
   * <a href="http://www.opengeospatial.org/standards/kml/">OGC KML (Keyhole Markup Language)</a>.
   */
  public static final MediaType KML = createConstant(APPLICATION_TYPE, "vnd.google-earth.kml+xml");

  /**
   * <a href="http://www.opengeospatial.org/standards/kml/">OGC KML (Keyhole Markup Language)</a>,
   * compressed using the ZIP format into KMZ archives.
   */

  /*
   * We use large numbers to avoid the integer cache. Normally, we'd accomplish that merely by using
   * `new Integer` (as we do) instead of `Integer.valueOf`. However, under J2KT, `new Integer`
   * gets translated back to `Integer.valueOf` because that is the only thing J2KT can support. And
   * anyway, it's nice to avoid `Integer.valueOf` because the Android toolchain optimizes multiple

  /*
   * We use large numbers to avoid the integer cache. Normally, we'd accomplish that merely by using
   * `new Integer` (as we do) instead of `Integer.valueOf`. However, under J2KT, `new Integer`
   * gets translated back to `Integer.valueOf` because that is the only thing J2KT can support. And
   * anyway, it's nice to avoid `Integer.valueOf` because the Android toolchain optimizes multiple

   * ParametricNullness parametric nullness}. Sometimes, code may receive a null {@code T} but store
   * a "null sentinel" to take its place. When the time comes to convert it back to a {@code T} to
   * return to a caller, the code needs to a way to return {@code null} from a method that returns
   * "plain {@code T}." This API provides that.
   */