In this case, it will be mounted at the path `/subapi`:

{* ../../docs_src/sub_applications/tutorial001.py hl[11, 19] *}

### Check the automatic API docs { #check-the-automatic-api-docs }

Now, run the `fastapi` command with your file:

<div class="termy">

```console
$ fastapi dev main.py

### 3.1 Automatic removal of non current objects versions

A non-current object version is a version which is not the latest for a given object. It is possible to set up an automatic removal of non-current versions when a version becomes older than a given number of days.

This could be useful if for example you live in a country that restricts some URLs.

### Disable the automatic docs { #disable-the-automatic-docs }

The first step is to disable the automatic docs, as by default, those use the default CDN.

To disable them, set their URLs to `None` when creating your `FastAPI` app:

{* ../../docs_src/custom_docs_ui/tutorial001.py hl[8] *}

///

/// info

To declare headers, you need to use `Header`, because otherwise the parameters would be interpreted as query parameters.

///

## Automatic conversion { #automatic-conversion }

`Header` has a little extra functionality on top of what `Path`, `Query` and `Cookie` provide.

Even if they are in different modules (Python files).

///

## Exclude from OpenAPI { #exclude-from-openapi }

To exclude a *path operation* from the generated OpenAPI schema (and thus, from the automatic documentation systems), use the parameter `include_in_schema` and set it to `False`:

{* ../../docs_src/path_operation_advanced_configuration/tutorial003.py hl[6] *}

* Automatic data model documentation with <a href="https://json-schema.org/" class="external-link" target="_blank"><strong>JSON Schema</strong></a> (as OpenAPI itself is based on JSON Schema).
* Designed around these standards, after a meticulous study. Instead of an afterthought layer on top.
* This also allows using automatic **client code generation** in many languages.

It was one of the first examples of **automatic API documentation**, and this was specifically one of the first ideas that inspired "the search for" **FastAPI**.

/// note

Django REST Framework was created by Tom Christie. The same creator of Starlette and Uvicorn, on which **FastAPI** is based.

///

/// check | Inspired **FastAPI** to

Have an automatic API documentation web user interface.

///

    * FastAPI provides more features on top of Starlette. Features that you almost always need when building APIs, like data validation and serialization. And by using it, you get automatic documentation for free (the automatic documentation doesn't even add overhead to running applications, it is generated on startup).

<img src="/img/tutorial/path-params/image01.png">

/// check

Again, just with that same Python type declaration, **FastAPI** gives you automatic, interactive documentation (integrating Swagger UI).

Notice that the path parameter is declared to be an integer.

///

    /**
     * Not idempotent operation packet flag
     */
    int RPC_C_PF_NOT_IDEMPOTENT = 0x20;
    /**
     * No automatic listening packet flag
     */
    int RPC_C_PF_NO_AUTO_LISTEN = 0x40;
    /**
     * No automatic retry packet flag
     */
    int RPC_C_PF_NO_AUTO_RETRY = 0x80;