!!! tip
    The next sections are **not necessarily "advanced"**.

    And it's possible that for your use case, the solution is in one of them.

## Read the Tutorial first

The next sections assume you already read the main [Tutorial - User Guide: Security](../../tutorial/security/index.md){.internal-link target=_blank}.

* **By default**, that would mean that you can only have **one HTTPS certificate per IP address**.
    * No matter how big your server is or how small each application you have on it might be.
    * There is a **solution** to this, however.

    * This is not really a bug in FastAPI but in Swagger UI, nevertheless pinning the version will work while a solution is found on the [Swagger UI side](https://github.com/swagger-api/swagger-ui/issues/9337).

### Docs

* Then check if the question (the vast majority are questions) is **clear**.

* In many cases the question asked is about an imaginary solution from the user, but there might be a **better** one. If you can understand the problem and use case better, you might be able to suggest a better **alternative solution**.

* If you can't understand the question, ask for more **details**.

### Reproduce the problem

In the next sections you will see other options, configurations, and additional features.

!!! tip
    The next sections are **not necessarily "advanced"**.

    And it's possible that for your use case, the solution is in one of them.

## Read the Tutorial first

You could still use most of the features in **FastAPI** with the knowledge from the main [Tutorial - User Guide](../tutorial/index.md){.internal-link target=_blank}.

  - author: Ben Gamble
    author_link: https://uk.linkedin.com/in/bengamble7
    link: https://ably.com/blog/realtime-ticket-booking-solution-kafka-fastapi-ably
    title: Building a realtime ticket booking solution with Kafka, FastAPI, and Ably
  - author: Shahriyar(Shako) Rzayev
    author_link: https://www.linkedin.com/in/shahriyar-rzayev/

                    `response_model`, converting any data as necessary to generate the
                    corresponding JSON. But if the data in the object returned is not
                    valid, that would mean a violation of the contract with the client,
                    so it's an error from the API developer. So, FastAPI will raise an
                    error and return a 500 error code (Internal Server Error).

!!! note "Remarque"
    Les sections de ce chapitre ne sont **pas nécessairement "avancées"**.

    Et il est possible que pour votre cas d'utilisation, la solution se trouve dans l'un d'entre eux.

## Lisez d'abord le didacticiel

        *,
        websocket: WebSocket,
        session: Annotated[str | None, Cookie()] = None,
        item_id: str,
    ):
        if session is None:
            raise WebSocketException(code=status.WS_1008_POLICY_VIOLATION)
        await websocket.accept()
        while True:
            data = await websocket.receive_text()
            await websocket.send_text(f"Session cookie is: {session}")

                    `response_model`, converting any data as necessary to generate the
                    corresponding JSON. But if the data in the object returned is not
                    valid, that would mean a violation of the contract with the client,
                    so it's an error from the API developer. So, FastAPI will raise an
                    error and return a 500 error code (Internal Server Error).