Steps to reproduce the issue

GET to:
{{base_path}}/api/index.php/v1/content/article/6
You'll see the following fields are available in the Joomla backend but missing in the API.
In order (Top to bottom, left to right).

Skipping Edit Screen for now along with permissions Tab as well.

Expected result

In theory all fields available in the backend should be visible via the API too assuming we are gearing towards making with 100% API driven.

Actual result

After the following PR #30134 we have the below result on single article.

{
    "links": {
        "self": "http://localhost/joomla4/api/index.php/v1/content/article/6"
    },
    "data": {
        "type": "articles",
        "id": "6",
        "attributes": {
            "typeAlias": "com_content.article",
            "id": 6,
            "asset_id": 91,
            "title": "Title of Article goes here",
            "state": 1,
            "created": "2020-07-18 10:47:32",
            "images": {
                "image_intro": "",
                "float_intro": "",
                "image_intro_alt": "",
                "image_intro_caption": "",
                "image_fulltext": "",
                "float_fulltext": "",
                "image_fulltext_alt": "",
                "image_fulltext_caption": ""
            },
            "metakey": "This is this",
            "metadesc": "This",
            "access": 1,
            "metadata": {
                "robots": "noindex, follow",
                "author": "Author",
                "rights": "No Rights possible"
            },
            "featured": 1,
            "language": "*",
            "tags": [],
            "text": "My text "
        },
        "relationships": {
            "category": {
                "data": {
                    "type": "categories",
                    "id": "8"
                }
            },
            "author": {
                "data": {
                    "type": "users",
                    "id": "815"
                }
            }
        }
    }
}

System information (as much as possible)

Joomla 4 Beta 2 tested until PR #30134

Additional comments

If approved, most likely assignment for @alikon :)