And that function takes parameters in the same way that *path operation functions* do.

/// tip

You'll see what other "things", apart from functions, can be used as dependencies in the next chapter.

///

Whenever a new request arrives, **FastAPI** will take care of:

* Calling your dependency ("dependable") function with the correct parameters.
* Get the result from your function.

This code is something you can actually use in your application, save the password hashes in your database, etc.

We are going to start from where we left in the previous chapter and increment it.

## About JWT

JWT means "JSON Web Tokens".

It's a standard to codify a JSON object in a long dense string without spaces. It looks like this:

```

But even if you never use **FastAPI**, you would benefit from learning a bit about them.

/// note

If you are a Python expert, and you already know everything about type hints, skip to the next chapter.

///

## Motivation

Let's start with a simple example:

{* ../../docs_src/python_types/tutorial001.py *}

Calling this program outputs:

```
John Doe
```

En déclarant les types de vos variables, cela permet aux différents outils comme les éditeurs de texte d'offrir un meilleur support.

Ce chapitre n'est qu'un **tutoriel rapide / rappel** sur les annotations de type Python.
Seulement le minimum nécessaire pour les utiliser avec **FastAPI** sera couvert... ce qui est en réalité très peu.

/// tip

All this might seem contrived. And it might not be very clear how is it useful yet.

These examples are intentionally simple, but show how it all works.

In the chapters about security, there are utility functions that are implemented in this same way.

If you understood all this, you already know how those utility tools for security work underneath.

       * doesn't need access to the futures again, so we can just pass `null`.
       *
       * TODO(b/112550045): Allocating a single, cheaper listener is (I think) only an optimization.
       * If we make some other optimizations, this one will no longer be necessary. The optimization

h3. Plugins

* Execution model
* Metadata model
* Metadata tooling
 ** Metadata extractor
 ** Metadata reader
 ** Metadata writer
 ** Metadata adapter (if required for the target system)
* Maven packaging and lifecycle
* Maven test harness for plugin execution model
* Eclipse IDE tooling for plugin execution model and metadata model

- we also seem to have information like the plugin lifecycle model that's buried inside the maven execution model

  minutes in the past relative to the current system time to workaround cases of
  clock desync. ([#118922](https://github.com/kubernetes/kubernetes/pull/118922), [@champtar](https://github.com/champtar))
- `plugin_evaluation_total` metric supports prescore/score extension point.

Anthony Barbier, Anton Kachatkou, Anubh-V, Anuja Jakhade, Artem Ryabov, autoih,
Bairen Yi, Bas Aarts, Basit Ayantunde, Ben Barsdell, Bhavani Subramanian, Brett
Koonce, candy.dc, Captain-Pool, caster, cathy, Chong Yan, Choong Yin Thong,
Clayne Robison, Colle, Dan Ganea, David Norman, David Refaeli, dengziming, Diego
Caballero, Divyanshu, djshen, Douman, Duncan Riach, EFanZh, Elena Zhelezina,