# OpenAPI Webhooks

There are cases where you want to tell your API **users** that your app could call *their* app (sending a request) with some data, normally to **notify** of some type of **event**.

This means that instead of the normal process of your users sending requests to your API, it's **your API** (or your app) that could **send requests to their system** (to their API, their app).

This is normally called a **webhook**.

## Webhooks steps

This method returns a function. And that function is what will receive a request and return a response.

Here we use it to create a `GzipRequest` from the original request.

```Python hl_lines="18-26"
{!../../../docs_src/custom_request_and_route/tutorial001.py!}
```

!!! note "Technical Details"
    A `Request` has a `request.scope` attribute, that's just a Python `dict` containing the metadata related to the request.

  // ResourceRules describes what operations on what resources/subresources the ValidatingAdmissionPolicy matches.
  // The policy cares about an operation if it matches _any_ Rule.
  // +listType=atomic
  // +optional
  repeated NamedRuleWithOperations resourceRules = 3;

  // ExcludeResourceRules describes what operations on what resources/subresources the ValidatingAdmissionPolicy should not care about.

  .
  .
  .
</plugins>

We need this form so that the model builder can make the first pass at merging. Full merging cannot be done because we don't know what the version of the plugin is yet that the user has requested. For plugins in the default lifecycle they are typically defined in the plugin management section of the parent POM. When the merging is complete we are going to have something that looks like the following:

<plugins>
  <plugin>

/**
 * A set of worker threads that are shared among a set of task queues.
 *
 * Use [INSTANCE] for a task runner that uses daemon threads. There is not currently a shared
 * instance for non-daemon threads.
 *
 * The task runner is also responsible for releasing held threads when the library is unloaded.
 * This is for the benefit of container environments that implement code unloading.
 *

  }

  /**
   * Returns the {@link Method} instance for {@link #testAddAll_unsupportedNonePresent()} so that
   * tests can suppress it with {@code FeatureSpecificTestSuiteBuilder.suppressing()} while we
   * figure out what to do with <a href="http://goo.gl/qJBruX">{@code ConcurrentHashMap} support for
   * {@code entrySet().add()}</a>.
   */
  @J2ktIncompatible

 * iterator} method only once, and should be tested using this class. Exceptions to this rule should
 * be clearly documented.
 *
 * <p>Note that although your APIs should be liberal in what they accept, your methods which
 * <i>return</i> iterables should make every attempt to return ones of the robust variety.
 *
 * <p>This testing utility is not thread-safe.
 *
 * @author Kevin Bourrillion

  * Otherwise, don't bind the mojo. Log a debug message to indicate that it is
    sensitive the online state of the application, and that this state is
    currently wrong for execution.

    <<NOTE:>> Do we want to fail when we cannot bind a mojo to the lifecycle
    because of offline/online status? That would probably indicate that the user
    was trying to do something they cannot succeed at for now...so we probably

to make sure we have an independent value in the `ContextVar` for each request that uses the database, and that value will be used as the database state (connection, transactions, etc) for the whole request.

For that, we need to create another `async` dependency `reset_db_state()` that is used as a sub-dependency in `get_db()`. It will set the value for the context variable (with just a default `dict`) that will be used as the database state for the whole request. And then the dependency...

   * <ul>
   *   <li>If {@code exceptions} has a single exception and that exception is a {@link
   *       RuntimeException}, return it
   *   <li>If {@code exceptions} has a single exceptions and that exceptions is not a
   *       {@link RuntimeException}, return a simple {@code RuntimeException} that wraps it
   *   <li>Otherwise, return an instance of {@link ClusterException} that wraps the first exception