///

The dependencies will keep working as expected, and the **best part** is that the **type information will be preserved**, which means that your editor will be able to keep providing you with **autocompletion**, **inline errors**, etc. The same for other tools like `mypy`.

/// info

Added in FastAPI 0.134.0.

///

## What is a Stream? { #what-is-a-stream }

"**Streaming**" data means that your app will start sending data items to the client without waiting for the entire sequence of items to be ready.

So, it will send the first item, the client will receive and start processing it, and you might still be producing the next item.

```mermaid
sequenceDiagram
    participant App

You can define logic (code) that should be executed before the application **starts up**. This means that this code will be executed **once**, **before** the application **starts receiving requests**.

The same way, you can define logic (code) that should be executed when the application is **shutting down**. In this case, this code will be executed **once**, **after** having handled possibly **many requests**.

 * acquire(1000)} will result in exactly the same throttling, if any), but it affects the throttling
 * of the <i>next</i> request. I.e., if an expensive task arrives at an idle RateLimiter, it will be
 * granted immediately, but it is the <i>next</i> request that will experience extra throttling,
 * thus paying for the cost of the expensive task.
 *

                be a Pydantic model, it could be other things, like a `list`, `dict`,
                etc.

                It will be used for:

                * Documentation: the generated OpenAPI (and the UI at `/docs`) will
                    show it as the response (JSON Schema).
                * Serialization: you could return an arbitrary object and the

     * The error's stacktrace will be output when this error level is enabled.
     *
     * @param content
     * @param error
     */
    void debug(CharSequence content, Throwable error);

    /**
     * Send an exception to the user in the <b>debug</b> error level.<br>
     * The stack trace for this exception will be output when this error level is enabled.
     *
     * @param error

# If the first character of an item is a question mark, the load will silently fail if the file does not exist.
${includes} = ?"${maven.user.conf}/maven-system.properties", \
              ?"${maven.project.conf}/maven-system.properties"

#
# Settings
#
# Define the default three levels for settings.
# The '-is' flag will override the 'maven.installation.settings' property.
# The '-ps' flag will override the 'maven.project.settings' property.

The response object will also have autocompletion:

<img src="/img/tutorial/generate-clients/image05.png">

## FastAPI App with Tags { #fastapi-app-with-tags }

In many cases, your FastAPI app will be bigger, and you will probably use tags to separate different groups of *path operations*.

For example, you could have a section for **items** and another section for **users**, and they could be separated by tags:

Those parameters are what **FastAPI** will use to "solve" the dependency.

In both cases, it will have:

* An optional `q` query parameter that is a `str`.
* A `skip` query parameter that is an `int`, with a default of `0`.
* A `limit` query parameter that is an `int`, with a default of `100`.

In both cases the data will be converted, validated, documented on the OpenAPI schema, etc.

   * captured by the returned {@link ClosingFuture}).
   *
   * <p>If this {@code ClosingFuture} succeeds, the derived one will be equivalent to the one
   * returned by the function.
   *
   * <p>If this {@code ClosingFuture} fails, the function will not be called, and the derived {@code
   * ClosingFuture} will be equivalent to this one.
   *
   * <p>If the function throws an exception, that exception is used as the result of the derived