```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

## `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`).

    - 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.