If you pass a "callable" as a dependency in **FastAPI**, it will analyze the parameters for that "callable", and process them in the same way as the parameters for a *path operation function*. Including sub-dependencies.

That also applies to callables with no parameters at all. The same as it would be for *path operation functions* with no parameters.

The argument:

```Python
connect_args={"check_same_thread": False}
```

...is needed only for `SQLite`. It's not needed for other databases.

!!! info "Technical Details"

    By default SQLite will only allow one thread to communicate with it, assuming that each thread would handle an independent request.

    This is to prevent accidentally sharing the same connection for different things (for different requests).

        default_value = value if value is not inspect.Signature.empty else Required
        if is_path_param:
            # We might check here that `default_value is Required`, but the fact is that the same
            # parameter might sometimes be a path parameter and sometimes not. See
            # `tests/test_infer_param_optionality.py` for an example.
            field_info = params.Path(annotation=use_annotation)

```

!!! tip
    ✔️ 🤯 👈 🚥 👆 💚 ⚙️ 🎏 💽, 💖 ✳, 👆 🚫 🚫 🔀 🎻. 👆 🔜 💪 ⚙️ 🎏 🏒 💽 🎓.

#### 🗒

❌:

```Python
check_same_thread=False
```

🌓 1️⃣ 🇸🇲 🔰:

```Python
connect_args={"check_same_thread": False}
```

...⚫️ 💪 🕴 `SQLite`.

!!! info "📡 ℹ"

    ⚫️❔ 🎏 📡 ℹ [🗄 (🔗) 💽](../tutorial/sql-databases.md#_7){.internal-link target=_blank} ✔.

                    (param["in"], param["name"]): param
                    for param in parameters
                    if param.get("required")
                }
                # Make sure required definitions of the same parameter take precedence
                # over non-required definitions
                all_parameters.update(required_parameters)
                operation["parameters"] = list(all_parameters.values())

## `fastapi-slim`

If you don't want the extra standard optional dependencies, install `fastapi-slim` instead.

When you install with:

```bash
pip install fastapi
```

...it includes the same code and dependencies as:

```bash
pip install "fastapi-slim[standard]"
```

The standard extra dependencies are the ones mentioned above.

## License

                }
            },
            "/response_model-no_annotation-return_same_model": {
                "get": {
                    "summary": "Response Model No Annotation Return Same Model",
                    "operationId": "response_model_no_annotation_return_same_model_response_model_no_annotation_return_same_model_get",
                    "responses": {
                        "200": {

Linux containers run using the same Linux kernel of the host (machine, virtual machine, cloud server, etc). This just means that they are very lightweight (compared to full virtual machines emulating an entire operating system).

    You can set `schema_extra` with a `dict` containing any additional data you would like to show up in the generated JSON Schema, including `examples`.

!!! tip
    You could use the same technique to extend the JSON Schema and add your own custom extra info.

    For example you could use it to add metadata for a frontend user interface, etc.

!!! info

        bool,
        Doc(
            """
            Pydantic's `exclude_defaults` parameter, passed to Pydantic models to define
            if it should exclude from the output the fields that had the same default
            value, even when they were explicitly set.
            """
        ),
    ] = False,
    exclude_none: Annotated[
        bool,
        Doc(
            """