<img src="/img/tutorial/generate-clients/image06.png">

In this case you have:

* `ItemsService`
* `UsersService`

### Client Method Names

Right now the generated method names like `createItemItemsPost` don't look very clean:

```TypeScript
ItemsService.createItemItemsPost({name: "Plumbus", price: 5})
```

    return {"message": "Hello World"}
```

See the similarities in `requests.get(...)` and `@app.get(...)`.

!!! check "Inspired **FastAPI** to"
    * Have a simple and intuitive API.
    * Use HTTP method names (operations) directly, in a straightforward and intuitive way.
    * Have sensible defaults, but powerful customizations.

I think `Union[SomeType, None]` is more explicit about what it means.

It's just about the words and names. But those words can affect how you and your teammates think about the code.

As an example, let's take this function:

```Python hl_lines="1  4"
{!../../../docs_src/python_types/tutorial009c.py!}
```

But don't worry, you can show it as you wish to your final users in the frontend.

And your database models can use any other names you want.

But for the login *path operation*, we need to use these names to be compatible with the spec (and be able to, for example, use the integrated API documentation system).

It would depend mainly on the tool you use to **install** those requirements.

The most common way to do it is to have a file `requirements.txt` with the package names and their versions, one per line.

You would of course use the same ideas you read in [About FastAPI versions](versions.md){.internal-link target=_blank} to set the ranges of versions.