---

## Install FastAPI

The first step is to install FastAPI:

<div class="termy">

```console
$ pip install fastapi

---> 100%
```

</div>

!!! note
    When you install with `pip install fastapi` it comes with some default optional standard dependencies.

    If you don't want to have those optional dependencies, you can instead install `pip install fastapi-slim`.

@app.get("/")
async def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
async def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

**Note**:

If you don't know, check the _"In a hurry?"_ section about <a href="https://fastapi.tiangolo.com/async/#in-a-hurry" target="_blank">`async` and `await` in the docs</a>.

</details>

### Run it