val firefox53 = sslLabsClients.first { it.userAgent == "Firefox" && it.version == "53" }
  val firefox73 = sslLabsClients.first { it.userAgent == "Firefox" && it.version == "73" }
  val java7 = sslLabsClients.first { it.userAgent == "Java" && it.version == "7u25" }
  val java12 = sslLabsClients.first { it.userAgent == "Java" && it.version == "12.0.1" }

The `lifespan` parameter of the `FastAPI` app takes an **async context manager**, so we can pass our new `lifespan` async context manager to it.

```Python hl_lines="22"
{!../../../docs_src/events/tutorial003.py!}
```

## Alternative Events (deprecated)

!!! warning

    This defines the name of the query parameter that should be provided in the request
    with the API key and integrates that into the OpenAPI documentation. It extracts
    the key value sent in the query parameter automatically and provides it as the
    dependency result. But it doesn't define how to send that API key to the client.

    ## Usage

    Create an instance object and use that object as the dependency in `Depends()`.

  val call = okHttpClient.newCall(Request(url.toHttpUrl()))

  val suites =
    call.executeAsync().use {
      if (!it.isSuccessful) {
        throw IOException("Failed ${it.code} ${it.message}")
      }
      it.body.string().lines()
        .mapNotNull { parseIanaCsvRow(it) }
    }

  return IanaSuites("current", suites)

To create the callback *path operation* use the same `APIRouter` you created above.

It should look just like a normal FastAPI *path operation*:

* It should probably have a declaration of the body it should receive, e.g. `body: InvoiceEvent`.
* And it could also have a declaration of the response it should return, e.g. `response_model=InvoiceEventReceived`.

```Python hl_lines="16-18  21-22  28-32"

* **FastAPI**:
    * The same way that Starlette uses Uvicorn and cannot be faster than it, **FastAPI** uses Starlette, so it cannot be faster than it.

You can declare a parameter in a *path operation function* or dependency to be of type `Response` and then you can set data for the response like headers or cookies.

You can also use it directly to create an instance of it and return it from your *path operations*.

You can import it directly from `fastapi`:

```python
from fastapi import Response
```

def currentDistroJars = currentClasspath.filter { it.name.startsWith('gradle-') && it.name.endsWith('.jar') }
def baselineJars = configurations.baselineJars
def baseVersion = moduleIdentity.version.map { it.baseVersion.version }

dependencies {
    baseline("gradle:gradle:${compatibilityBaselineVersion}@zip")

    // This transform takes the Gradle zip distribution,
    // and unzips the Gradle jar files that it contains in a directory

!!! note "Technical details"
    In the OpenAPI specification it is called the <a href="https://github.com/OAI/OpenAPI-Specification/blob/main/versions/3.0.3.md#operation-object" class="external-link" target="_blank">Operation Object</a>.

It has all the information about the *path operation* and is used to generate the automatic documentation.

It includes the `tags`, `parameters`, `requestBody`, `responses`, etc.

In the output, you can see that it shows the **PID** (process ID) of each process (it's just a number).

You can see that:

* The Gunicorn **process manager** starts with PID `19499` (in your case it will be a different number).
* Then it starts `Listening at: http://0.0.0.0:80`.
* Then it detects that it has to use the worker class at `uvicorn.workers.UvicornWorker`.