## Steps { #steps }

So, let's say you have a frontend running in your browser at `http://localhost:8080`, and its JavaScript is trying to communicate with a backend running at `http://localhost` (because we don't specify a port, the browser will assume the default port `80`).

```
http://localhost:8000/v1/agents/multivac
```

Even though the host of the malicious website and the local app is different, the browser won't trigger a CORS preflight request because:

* It's running without any authentication, it doesn't have to send any credentials.
* The browser thinks it's not sending JSON (because of the missing `Content-Type` header).

    // 3) Caller specified but assuming the visible defaults in MODERN_CIPHER_SUITES are rejigged
    // to match legacy i.e. the platform/provider
    //
    // Opting for 2 here and keeping MODERN_TLS in line with secure browsers.
    cipherSuitesAsString.intersect(socketEnabledCipherSuites, CipherSuite.ORDER_BY_NAME)
  } else {
    socketEnabledCipherSuites
  }

internal fun MediaType?.chooseCharset(): Pair<Charset, MediaType?> {

   * {@code co.uk}, {@code google.invalid}, or {@code blogspot.com}.
   *
   * <p>This method can be used to determine whether it will probably be possible to set cookies on
   * the domain, though even that depends on individual browsers' implementations of cookie
   * controls. See <a href="http://www.ietf.org/rfc/rfc2109.txt">RFC 2109</a> for details.
   *
   * @since 6.0
   */
  public boolean isUnderPublicSuffix() {

You can see the defined cookies in the docs UI at `/docs`:

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

/// info

Have in mind that, as **browsers handle cookies** in special ways and behind the scenes, they **don't** easily allow **JavaScript** to touch them.

You can stream data to the client using **Server-Sent Events** (SSE).

This is similar to [Stream JSON Lines](stream-json-lines.md), but uses the `text/event-stream` format, which is supported natively by browsers with the [`EventSource` API](https://developer.mozilla.org/en-US/docs/Web/API/EventSource).

/// info

Added in FastAPI 0.135.0.

///

## What are Server-Sent Events? { #what-are-server-sent-events }

            if (e.key === 'Enter' && !e.shiftKey && !e.isComposing) {
                e.preventDefault();
                sendMessage();
            }
        });

        // Handle IME composition for older browsers
        elements.chatInput.on('compositionstart', function() {
            elements.chatInput.data('composing', true);
        });
        elements.chatInput.on('compositionend', function() {

  /** Returns true if this cookie should be limited to only HTTPS requests. */
  @get:JvmName("secure") val secure: Boolean,
  /**
   * Returns true if this cookie should be limited to only HTTP APIs. In web browsers this prevents
   * the cookie from being accessible to scripts.
   */
  @get:JvmName("httpOnly") val httpOnly: Boolean,
  /**
   * Returns true if this cookie does not expire at the end of the current session.
   *

 * direct translation of the pseudocode presented there.
 *
 * Partner this class with [UTS #46] to implement IDNA2008 [RFC 5890] like most browsers do.
 *
 * [RFC 3492]: https://datatracker.ietf.org/doc/html/rfc3492
 * [RFC 5890]: https://datatracker.ietf.org/doc/html/rfc5890
 * [UTS #46]: https://www.unicode.org/reports/tr46/
 */
object Punycode {

      }

      HTTP_CLIENT_TIMEOUT -> {
        // 408's are rare in practice, but some servers like HAProxy use this response code. The
        // spec says that we may repeat the request without modifications. Modern browsers also
        // repeat the request (even non-idempotent ones.)
        if (!chain.retryOnConnectionFailure) {
          // The application layer has directed us not to retry the request.
          return null
        }