{* ../../docs_src/header_param_models/tutorial001_an_py310.py hl[9:14,18] *}

**FastAPI** will **extract** the data for **each field** from the **headers** in the request and give you the Pydantic model you defined.

## Check the Docs { #check-the-docs }

You can see the required headers in the docs UI at `/docs`:

<div class="screenshot">
<img src="/img/tutorial/header-param-models/image01.png">
</div>

  private fun WebSocketExtensions.isValid(): Boolean {
    // If the server returned parameters we don't understand, fail the web socket.
    if (unknownValues) return false

    // If the server returned a value for client_max_window_bits, fail the web socket.
    if (clientMaxWindowBits != null) return false

    // If the server returned an illegal server_max_window_bits, fail the web socket.

- Temporary credentials do not need to be stored with the application but are generated dynamically and provided to the application when requested. When (or even before) the temporary credentials expire, the application can request new credentials.

Following are advantages for using temporary credentials:

- Eliminates the need to embed long-term credentials with an application.

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