The process that happens when your API app calls the *external API* is named a "callback". Because the software that the external developer wrote sends a request to your API and then your API *calls back*, sending a request to an *external API* (that was probably created by the same developer).

{* ../../docs_src/dependencies/tutorial013_an_py310.py ln[19:21] *}

...would be run after the response finishes sending the slow data:

{* ../../docs_src/dependencies/tutorial013_an_py310.py ln[30:38] hl[31:33] *}

But as `generate_stream()` doesn't use the database session, it is not really necessary to keep the session open while sending the response.

* 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).

Then the malicious website could make the local AI agent send angry messages to the user's ex-boss... or worse. 😅

## Open Internet { #open-internet }

## Raw Data { #raw-data }

If you need to send data **without** JSON encoding, use `raw_data` instead of `data`.

This is useful for sending pre-formatted text, log lines, or special <dfn title="A value used to indicate a special condition or state">"sentinel"</dfn> values like `[DONE]`.

{* ../../docs_src/server_sent_events/tutorial003_py310.py hl[17] *}

/// note

```console
$ pip install python-multipart
```

This is because **OAuth2** uses "form data" for sending the `username` and `password`.

///

Run the example with:

<div class="termy">

```console
$ fastapi dev

  }

  override fun flushRequest() {
    socket.sink.flush()
  }

  override fun finishRequest() {
    socket.sink.flush()
  }

  /** Returns bytes of a request header for sending on an HTTP transport. */
  fun writeRequest(
    headers: Headers,
    requestLine: String,
  ) {
    check(state == STATE_IDLE) { "state: $state" }
    socket.sink.writeUtf8(requestLine).writeUtf8("\r\n")

    }
    body.awaitSuccess()
    assertThat(log.take()!!)
      .contains("StreamResetException: stream was reset: CANCEL")
  }

  /**
   * We delay sending the last byte of the request body 1500 ms. The 1000 ms read timeout should
   * only elapse 1000 ms after the request body is sent.
   */
  @Test
  fun headersReadTimeoutDoesNotStartUntilLastRequestBodyByteFire() {

To declare a **request** body, you use [Pydantic](https://docs.pydantic.dev/) models with all their power and benefits.

/// info

To send data, you should use one of: `POST` (the more common), `PUT`, `DELETE` or `PATCH`.

Sending a body with a `GET` request has an undefined behavior in the specifications, nevertheless, it is supported by FastAPI, only for very complex/extreme use cases.

the server (the machine, host, etc.) and **managing all the HTTPS parts**: receiving the **encrypted HTTPS requests**, sending the **decrypted HTTP requests** to the actual HTTP application running in the same server (the **FastAPI** application, in this case), take the **HTTP response** from the application, **encrypt it** using the appropriate **HTTPS certificate** and sending it back to the client using **HTTPS**. This server is often called a **[TLS Termination Proxy](https://en.wikipedia.or...

     * @throws JobNotFoundException if no process is found for the given session ID
     * @throws JobProcessingException if there's an error sending the command
     */
    public void sendCommand(final String sessionId, final String command) {
        final Process process;
        synchronized (this) {
            final JobProcess jobProcess = runningProcessMap.get(sessionId);