To run any of the examples, copy the code to a file `main.py`, and start `fastapi dev` with:

<div class="termy">

```console
$ <font color="#4E9A06">fastapi</font> dev <u style="text-decoration-style:single">main.py</u>
<font color="#3465A4">INFO    </font> Using path <font color="#3465A4">main.py</font>

maven-deploy-plugin 0.1 maven-plugin Maven Integration Test Plugin A test plugin to assist testing of Maven core. 2009 maven-core-it file:///${basedir}/repo true true org.apache.maven maven-plugin-api 2.0 . pom.xml src/** src/main/resources src/main/java/org/apache/maven/plugins/coreit/ItMojo.java src/main/java/org/apache/maven/plugins/coreit/ItMojo.java package org.apache.maven.plugin.coreit; /* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE...

<span style="color: green;">INFO</span>:     Application startup complete.
```

</div>

!!! note
    📋 `uvicorn main:app` 🔗:

    * `main`: 📁 `main.py` (🐍 "🕹").
    * `app`: 🎚 ✍ 🔘 `main.py` ⏮️ ⏸ `app = FastAPI()`.
    * `--reload`: ⚒ 💽 ⏏ ⏮️ 📟 🔀. 🕴 ⚙️ 🛠️.

🔢, 📤 ⏸ ⏮️ 🕳 💖:

```hl_lines="4"

maven-clean-plugin 0.1 maven-plugin Maven Integration Test Plugin A test plugin to assist testing of Maven core. 2009 maven-core-it file:///${basedir}/repo true true org.apache.maven maven-plugin-api 2.0 . pom.xml src/** src/main/resources src/main/java/org/apache/maven/plugins/coreit/ItMojo.java src/main/java/org/apache/maven/plugins/coreit/ItMojo.java package org.apache.maven.plugin.coreit; /* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE...

maven-surefire-plugin 0.1 maven-plugin Maven Integration Test Plugin A test plugin to assist testing of Maven core. 2009 maven-core-it file:///${basedir}/repo true true org.apache.maven maven-plugin-api 2.0 . pom.xml src/** src/main/resources src/main/java/org/apache/maven/plugins/coreit/ItMojo.java src/main/java/org/apache/maven/plugins/coreit/ItMojo.java package org.apache.maven.plugin.coreit; /* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE...

```

</div>

➡️ 👀 ⚫️❔ 🔠 👈 🎛 ⛓:

* `main:app`: 👉 🎏 ❕ ⚙️ Uvicorn, `main` ⛓ 🐍 🕹 📛 "`main`",, 📁 `main.py`. &amp; `app` 📛 🔢 👈 **FastAPI** 🈸.
    * 👆 💪 🌈 👈 `main:app` 🌓 🐍 `import` 📄 💖:

        ```Python
        from main import app
        ```

    * , ❤ `main:app` 🔜 🌓 🐍 `import` 🍕 `from main import app`.
* `--workers`: 🔢 👨‍🏭 🛠️ ⚙️, 🔠 🔜 🏃 Uvicorn 👨‍🏭, 👉 💼, 4️⃣ 👨‍🏭.

<span style="color: green;">INFO</span>:     Application startup complete.
```

</div>

!!! note "Nota"
    O comando `uvicorn main:app` se refere a:

    * `main`: o arquivo `main.py` (o "módulo" Python).
    * `app`: o objeto criado no arquivo `main.py` com a linha `app = FastAPI()`.
    * `--reload`: faz o servidor reiniciar após mudanças de código. Use apenas para desenvolvimento.

Na saída, temos:

```

</div>

Let's see what each of those options mean:

* `main:app`: This is the same syntax used by Uvicorn, `main` means the Python module named "`main`", so, a file `main.py`. And `app` is the name of the variable that is the **FastAPI** application.
    * You can imagine that `main:app` is equivalent to a Python `import` statement like:

        ```Python
        from main import app
        ```

<div class="termy">

```console
$ <font color="#4E9A06">fastapi</font> dev <u style="text-decoration-style:single">main.py</u>
<font color="#3465A4">INFO    </font> Using path <font color="#3465A4">main.py</font>
<font color="#3465A4">INFO    </font> Resolved absolute path <font color="#75507B">/home/user/code/awesomeapp/</font><font color="#AD7FA8">main.py</font>

    /**
     * Resolves the main artifact of the specified plugin.
     *
     * @param plugin The plugin for which to resolve the main artifact, must not be {@code null}.
     * @param repositories The plugin repositories to use for resolving the plugin's main artifact, must not be {@code
     *            null}.
     * @param session The repository session to use for resolving the plugin's main artifact, must not be {@code null}.