> What’s the history of this project? It seems to have come from nowhere to awesome in a few weeks [...]

Here's a little bit of that history.

## Alternatives

I have been creating APIs with complex requirements for several years (Machine Learning, distributed systems, asynchronous jobs, NoSQL databases, etc), leading several teams of developers.

As part of that, I needed to investigate, test and use many alternatives.

## Mounting a **FastAPI** application

"Mounting" means adding a completely "independent" application in a specific path, that then takes care of handling everything under that path, with the _path operations_ declared in that sub-application.

### Top-level application

## Gunicorn with Uvicorn Workers

![ReDoc](https://fastapi.tiangolo.com/img/index/index-06-redoc-02.png)

### Just Modern Python

It's all based on standard **Python type** declarations (thanks to Pydantic). No new syntax to learn. Just standard modern Python.

If you need a 2 minute refresher of how to use Python types (even if you don't use FastAPI), check the short tutorial: [Python Types](python-types.md){.internal-link target=_blank}.

In all the docs there are examples compatible with each version of Python (when there's a difference).

For example "**Python 3.6+**" means it's compatible with Python 3.6 or above (including 3.7, 3.8, 3.9, 3.10, etc). And "**Python 3.9+**" means it's compatible with Python 3.9 or above (including 3.10, etc).

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:

```

there are restrictions on passing pointers between Go and C.

In this section the term Go pointer means a pointer to memory
allocated by Go (such as by using the & operator or calling the
predefined new function) and the term C pointer means a pointer to
memory allocated by C (such as by a call to C.malloc). Whether a
pointer is a Go pointer or a C pointer is a dynamic property

		}
	} else if *retention.Years == 0 {
		return fmt.Errorf("Default retention period must be a positive integer value for 'Years'")
	} else if *retention.Years > maximumRetentionYears {
		return fmt.Errorf("Default retention period too large for 'Years' %d", *retention.Years)
	}

	*dr = DefaultRetention(retention)

	return nil
}

  // "" (empty) means "all" for namespace scoped resources from a SubjectAccessReview or SelfSubjectAccessReview
  // +optional
  optional string namespace = 1;

  // Verb is a kubernetes resource API verb, like: get, list, watch, create, update, delete, proxy.  "*" means all.
  // +optional
  optional string verb = 2;

  // Group is the API Group of the Resource.  "*" means all.
  // +optional

## `fastapi run`

When you run `fastapi run`, it will run on production mode by default.

It will have **auto-reload disabled** by default.

It will listen on the IP address `0.0.0.0`, which means all the available IP addresses, this way it will be publicly accessible to anyone that can communicate with the machine. This is how you would normally run it in production, for example, in a container.