fastapi/docs/en/docs/fastapi-cli.md

# FastAPI CLI { #fastapi-cli }

**FastAPI CLI** is a command-line tool that helps you serve your FastAPI application, manage your project, and perform various development tasks.

When you install FastAPI (e.g. with `pip install "fastapi[standard]"`), it includes the fastapi-cli package, which provides the `fastapi` command in your terminal.

To run your FastAPI app for development, you can use the `fastapi dev` command:

<div class="termy">

```console
$ <font color="#4E9A06">fastapi</font> dev <u style="text-decoration-style:solid">main.py</u>

<span style="background-color:#009485"><font color="#D3D7CF"> FastAPI </font></span>  Starting development server 🚀

        Searching for package file structure from directories with
        <font color="#3465A4">__init__.py</font> files
        Importing from <font color="#75507B">/home/user/code/</font><font color="#AD7FA8">awesomeapp</font>

<span style="background-color:#007166"><font color="#D3D7CF"> module </font></span>  🐍 main.py

<span style="background-color:#007166"><font color="#D3D7CF"> code </font></span>  Importing the FastAPI app object from the module with the
        following code:

        <u style="text-decoration-style:solid">from </u><u style="text-decoration-style:solid"><b>main</b></u><u style="text-decoration-style:solid"> import </u><u style="text-decoration-style:solid"><b>app</b></u>

<span style="background-color:#007166"><font color="#D3D7CF"> app </font></span>  Using import string: <font color="#3465A4">main:app</font>

<span style="background-color:#007166"><font color="#D3D7CF"> server </font></span>  Server started at <font color="#729FCF"><u style="text-decoration-style:solid">http://127.0.0.1:8000</u></font>
<span style="background-color:#007166"><font color="#D3D7CF"> server </font></span>  Documentation at <font color="#729FCF"><u style="text-decoration-style:solid">http://127.0.0.1:8000/docs</u></font>

<span style="background-color:#007166"><font color="#D3D7CF"> tip </font></span>  Running in development mode, for production use:
        <b>fastapi run</b>

        Logs:

<span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Will watch for changes in these directories:
        <b>[</b><font color="#4E9A06">&apos;/home/user/code/awesomeapp&apos;</font><b>]</b>
<span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Uvicorn running on <font color="#729FCF"><u style="text-decoration-style:solid">http://127.0.0.1:8000</u></font> <b>(</b>Press CTRL+C to
        quit<b>)</b>
<span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Started reloader process <b>[</b><font color="#34E2E2"><b>383138</b></font><b>]</b> using WatchFiles
<span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Started server process <b>[</b><font color="#34E2E2"><b>383153</b></font><b>]</b>
<span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Waiting for application startup.
<span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Application startup complete.

The command line program called fastapi is FastAPI CLI.

FastAPI CLI takes the path to your Python file (e.g. main.py), automatically detects the FastAPI instance (usually named app), determines how it should be imported, and starts the server for you.

For production, you should use fastapi run instead. 🚀

Internally, FastAPI CLI uses Uvicorn, a high-performance, production-ready, ASGI server. 😎

fastapi dev

Running fastapi dev starts FastAPI in development mode.

By default, auto-reload is enabled, automatically reloading the server when you make changes to your code. Auto-reload is resource-intensive and may be less stable than running with it disabled. You should only use it for development. It also listens on the IP address 127.0.0.1, which is the address your machine uses to communicate with itself (localhost).

fastapi run

Running fastapi run starts FastAPI in production mode.

By default, auto-reload is disabled. It also listens on 0.0.0.0, which makes the application accessible on all available network interfaces. This is typically how you run a production server, such as inside a container.

In most cases, you should have a “termination proxy” handling HTTPS in front of your application. Depending on your deployment setup, your hosting provider may handle this, or you may need to configure it yourself.

/// tip

You can learn more about it in the deployment documentation{.internal-link target=_blank}.

///