## Resource Utilization

Your server(s) is (are) a **resource**, you can consume or **utilize**, with your programs, the computation time on the CPUs, and the RAM memory available.

    ```Python
    from main import app
    ```

!!! warning
    Uvicorn and others support a `--reload` option that is useful during development.

    The `--reload` option consumes much more resources, is more unstable, etc.

    It helps a lot during **development**, but you **shouldn't** use it in **production**.

## Hypercorn with Trio

...the path would be:

```
/items/foo
```

!!! info
    A "path" is also commonly called an "endpoint" or a "route".

While building an API, the "path" is the main way to separate "concerns" and "resources".

#### Operation

"Operation" here refers to one of the HTTP "methods".

One of:

* `POST`
* `GET`
* `PUT`
* `DELETE`

...and the more exotic ones:

* `OPTIONS`

## `fastapi dev`

When you run `fastapi dev`, it will run on development mode.

By default, it will have **auto-reload** enabled, so it will automatically reload the server when you make changes to your code. This is resource intensive and could be less stable than without it, you should only use it for development.

By default it will listen on the IP address `127.0.0.1`, which is the IP for your machine to communicate with itself alone (`localhost`).

Additionally, a background task is normally an independent set of logic that should be handled separately, with its own resources (e.g. its own database connection).

    - reference/openapi/models.md
  - reference/security/index.md
  - reference/encoders.md
  - reference/staticfiles.md
  - reference/templating.md
  - reference/testclient.md
- fastapi-people.md
- Resources:
  - resources/index.md
  - project-generation.md
  - external-links.md
  - newsletter.md
- About:
  - about/index.md
  - alternatives.md
  - history-design-future.md
  - benchmarks.md
- Help:

### Dependency Injection

FastAPI includes an extremely easy to use, but extremely powerful <abbr title='also known as "components", "resources", "services", "providers"'><strong>Dependency Injection</strong></abbr> system.

* Even dependencies can have dependencies, creating a hierarchy or **"graph" of dependencies**.
* All **automatically handled** by the framework.

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* How to set **validation constraints** as `maximum_length` or `regex`.
* A very powerful and easy to use **<abbr title="also known as components, resources, providers, services, injectables">Dependency Injection</abbr>** system.
* Security and authentication, including support for **OAuth2** with **JWT tokens** and **HTTP Basic** auth.

This way, containers consume **little resources**, an amount comparable to running the processes directly (a virtual machine would consume much more).