, 🚥 👆 🚫 🚚 1️⃣, **FastAPI** 🔜 🔁 🏗 1️⃣ "🏆 📨".

<img src="/img/tutorial/path-operation-configuration/image03.png">

## 😢 *➡ 🛠️*

🚥 👆 💪 ™ *➡ 🛠️* <abbr title="obsolete, recommended not to use it">😢</abbr>, ✋️ 🍵 ❎ ⚫️, 🚶‍♀️ 🔢 `deprecated`:

```Python hl_lines="16"
{!../../../docs_src/path_operation_configuration/tutorial006.py!}
```

⚫️ 🔜 🎯 ™ 😢 🎓 🩺:

        "items:read items:write users:read profile openid"
    client_id: optional string. OAuth2 recommends sending the client_id and client_secret (if any)
        using HTTP Basic auth, as: client_id:client_secret
    client_secret: optional string. OAuth2 recommends sending the client_id and client_secret (if any)
        using HTTP Basic auth, as: client_id:client_secret
    """

    def __init__(

```Python
q: Annotated[str, Query()] = "rick"
```

...or in older code bases you will find:

```Python
q: str = Query(default="rick")
```

### Advantages of `Annotated`

**Using `Annotated` is recommended** instead of the default value in function parameters, it is **better** for multiple reasons. 🤓

The **default** value of the **function parameter** is the **actual default** value, that's more intuitive with Python in general. 😌

app = FastAPI(lifespan=lifespan)


@app.get("/predict")
async def predict(x: float):
    result = ml_models["answer_to_everything"](x)
    return {"result": result}
```

**Note**: This is the recommended way going forward, instead of using `startup` and `shutdown` events.

Read more about it in the new docs: [Advanced User Guide: Lifespan Events](https://fastapi.tiangolo.com/advanced/events/).

### Docs

hon-sdk/2.5/async-programming.html#asyncio-python-3-5" class="external-link" target="_blank">experimental Python <code>await</code> support</a>, we should declare our function with normal `def` instead of `async def`.

Also, Couchbase recommends not using a single `Bucket` object in multiple "<abbr title="A sequence of code being executed by the program, while at the same time, or at intervals, there can be others being executed too.">thread</abbr>s", so, we can just get the bucket directly...

* 🚨 Avoid using `Optional[SomeType]`
* Instead ✨ **use `Union[SomeType, None]`** ✨.

Both are equivalent and underneath they are the same, but I would recommend `Union` instead of `Optional` because the word "**optional**" would seem to imply that the value is optional, and it actually means "it can be `None`", even if it's not optional and is still required.

---

"_If anyone is looking to build a production Python API, I would highly recommend **FastAPI**. It is **beautifully designed**, **simple to use** and **highly scalable**, it has become a **key component** in our API first development strategy and is driving many automations and services such as our Virtual TAC Engineer._"

    If you are just starting, the tutorial [SQL (Relational) Databases](../tutorial/sql-databases.md){.internal-link target=_blank} that uses SQLAlchemy should be enough.

    Feel free to skip this.

    Peewee is not recommended with FastAPI as it doesn't play well with anything async Python. There are several better alternatives.

!!! info
    These docs assume Pydantic v1.

---

---

"_If anyone is looking to build a production Python API, I would highly recommend **FastAPI**. It is **beautifully designed**, **simple to use** and **highly scalable**, it has become a **key component** in our API first development strategy and is driving many automations and services such as our Virtual TAC Engineer._"