How to add image to document created on start-up

Hi,
Following the steps described in Redirecting… , I want to create some objects each time my app starts.

I can successfully create an object with the following Request.json:

[
    {
        "jsonrpc": "2.0",
        "method": "ADD_DOCUMENT",
        "id": "AddArticle1",
        "params": {
            "document": {
                "Article": {
                    "ArticleData": {
                        "ArticleName": "Banane",
                        "Barcode": "11111",
                        "Price": "0,99"
                    }
                }
            },
            "documentModelName": "ArticleDocument",
            "locale": "en"
        }
    }
]

However my article has an aditional property “ArticlePhoto” which I would like to add to its creation on-startup. When I create an article via the app, a POST request such as below is send:

[
    {
        "jsonrpc": "2.0",
        "method": "ADD_DOCUMENT",
        "id": "AddArticle1",
        "params": {
            "document": {
                "Article": {
                    "ArticleData": {
                        "ArticlePhoto": {
                            "content": null,
                            "attachment_id": "b525092d-570e-4517-9b4d-888293613ef2",
                            "internal_filename": "banana.jpg",
                            "original_filename": "banana.jpg",
                            "size": 21417,
                            "mime_type": "image/jpeg"
                        },
                        "ArticleName": "Banane",
                        "Barcode": "11111",
                        "Price": "0,99"
                    }
                }
            },
            "documentModelName": "ArticleDocument",
            "locale": "en"
        }
    }
]

Unfortunately, using above as request.json makes the server fail on re-start

com.mgmtp.a12.dataservices.exception.UnexpectedException: Json-rpc error for path '{}': {}

which leads me to my question:
How can I add a picture to a request.json ?

Hello, I’m not aware of any functionality allowing you to upload or assign attachments on startup.