spiffe://cluster.local/ns/istio-system/sa/another-sa     NA       Unavailable      false          NA                                   NA                       NA

<img src="/img/tutorial/custom-response/image01.png">

## Available responses

Here are some of the available responses.

Keep in mind that you can use `Response` to return anything else, or even create a custom sub-class.

!!! note "Technical Details"

This program and the accompanying materials
are made available under the terms of the Eclipse Public License v2.0
and Eclipse Distribution License v1.0 which accompany this distribution.

The Eclipse Public License is available at
  https://www.eclipse.org/legal/epl-2.0/
and the Eclipse Distribution License is available at
  http://www.eclipse.org/org/documents/edl-v10.php.

The key features are:

* **Fast**: Very high performance, on par with **NodeJS** and **Go** (thanks to Starlette and Pydantic). [One of the fastest Python frameworks available](#performance).
* **Fast to code**: Increase the speed to develop features by about 200% to 300%. *
* **Fewer bugs**: Reduce about 40% of human (developer) induced errors. *

- The target JVM for the runtime. Each runtime has its own JVM compatibility constraints.
- Some base services that are available to code hosted by the runtime. This varies by runtime.
- Additional constraints. For example, the CLI client runtimes limit the libraries that are available to the code in that runtime, for performance reasons. 

Other modules and platforms define the services that they contribute to the runtime.

        //  candidate, `Candidate.substitutor` is not complete. maybe we can carry over the final substitutor if it's available from
        //  body resolve phase?
        val substitutor = when (fir) {
            is FirQualifiedAccessExpression -> fir.createSubstitutorFromTypeArguments(targetSymbol)

            firSymbolBuilder.buildSymbol(firDiagnostic.b),
            firDiagnostic.c,
            firDiagnostic as KtPsiDiagnostic,
            token,
        )
    }
    add(FirErrors.API_NOT_AVAILABLE) { firDiagnostic ->
        ApiNotAvailableImpl(
            firDiagnostic.a,
            firDiagnostic.b,
            firDiagnostic as KtPsiDiagnostic,
            token,
        )
    }

This can make it a lot easier for your users to **implement their APIs** to receive your **webhook** requests, they might even be able to autogenerate some of their own API code.

!!! info
    Webhooks are available in OpenAPI 3.1.0 and above, supported by FastAPI `0.99.0` and above.

## An app with webhooks

          routeDatabase = routeDatabase,
          connectionUser = connectionUser,
          fastFallback = fastFallback,
        )
      routeSelector = newRouteSelector
    }

    // List available IP addresses for the current proxy. This may block in Dns.lookup().
    if (!newRouteSelector.hasNext()) throw IOException("exhausted all routes")
    val newRouteSelection = newRouteSelector.next()

## `fastapi run`

When you run `fastapi run`, it will run on production mode by default.

It will have **auto-reload disabled** by default.

It will listen on the IP address `0.0.0.0`, which means all the available IP addresses, this way it will be publicly accessible to anyone that can communicate with the machine. This is how you would normally run it in production, for example, in a container.