* Read other ideas, articles, and read about tools I have created.
    * Follow me to read when I publish something new.

## Tweet about **FastAPI** { #tweet-about-fastapi }

[Tweet about **FastAPI**](https://x.com/compose/tweet?text=I'm loving @fastapi because... https://github.com/fastapi/fastapi) and let me and others know why you like it. 🎉

            Configuration parameters for Swagger UI.

            It defaults to [swagger_ui_default_parameters][fastapi.openapi.docs.swagger_ui_default_parameters].

            Read more about it in the
            [FastAPI docs about how to Configure Swagger UI](https://fastapi.tiangolo.com/how-to/configure-swagger-ui/).
            """
        ),
    ] = None,
) -> HTMLResponse:
    """

                The OAuth2 spec says it is required and MUST be the fixed string
                "password". This dependency is strict about it. If you want to be
                permissive, use instead the `OAuth2PasswordRequestForm` dependency
                class.

                Read more about it in the
                [FastAPI docs for Simple OAuth2 with Password and Bearer](https://fastapi.tiangolo.com/tutorial/security/simple-oauth2/).

    * That's one layer **below HTTP**.
    * So, the **certificate and encryption** handling is done **before HTTP**.
* **TCP doesn't know about "domains"**. Only about IP addresses.
    * The information about the **specific domain** requested goes in the **HTTP data**.
* The **HTTPS certificates** "certify" a **certain domain**, but the protocol and encryption happen at the TCP level, **before knowing** which domain is being dealt with.

I'll show you some concrete examples in the next chapters.

---

Then the next concepts to consider are all about the program running your actual API (e.g. Uvicorn).

## Program and Process { #program-and-process }

We will talk a lot about the running "**process**", so it's useful to have clarity about what it means, and what's the difference with the word "**program**".

### What is a Program { #what-is-a-program }

This is just a **quick tutorial / refresher** about Python type hints. It covers only the minimum necessary to use them with **FastAPI**... which is actually very little.

**FastAPI** is all based on these type hints, they give it many advantages and benefits.

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

/// note

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 { #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:

```

      Spliterator<T> fromSpliterator, Predicate<? super T> predicate) {
    checkNotNull(fromSpliterator);
    checkNotNull(predicate);
    @IgnoreJRERequirement // see earlier comment about redundancy
    final class Splitr implements Spliterator<T>, Consumer<T> {
      @Nullable T holder = null;

      @Override
      public void accept(@ParametricNullness T t) {
        this.holder = t;
      }

 *   <li>element extraction methods which facilitate the retrieval of certain elements (for example
 *       {@link #last})
 *   <li>query methods which answer questions about the {@code FluentIterable}'s contents (for
 *       example {@link #anyMatch})
 *   <li>conversion methods which copy the {@code FluentIterable}'s contents into a new collection
 *       or array (for example {@link #toList})

 *   <li>element extraction methods which facilitate the retrieval of certain elements (for example
 *       {@link #last})
 *   <li>query methods which answer questions about the {@code FluentIterable}'s contents (for
 *       example {@link #anyMatch})
 *   <li>conversion methods which copy the {@code FluentIterable}'s contents into a new collection
 *       or array (for example {@link #toList})