Need further info to create backend for Asset Manager

I'm trying to figure out how to write a backend (in ASP.NET Core) for the Asset Manager. I've looked at a few of the Wiki pages, but still a bit confused. What I'd really like is info about how to show existing assets, upload new ones, delete existing ones, etc. I did see that I can upload by using an upload endpoint as follows:

assetManager: {
    ...
    // Upload endpoint, set `false` to disable upload, default `false`
    upload: 'https://endpoint/upload/assets',

    // The name used in POST to pass uploaded files, default: `'files'`
    uploadName: 'files',
    ...
},

However, that's only for upload. What about delete and load all (to initialize first time)? I was hoping for something like this:

UPLOAD

Parameter: upload Example: upload: 'https://my-site/assets/upload' (HTTP POST) RESPONSE:

{
    success: true/false,
    message: 'Some message here'
}

LIST ALL

Parameter: list Example: list: 'https://my-site/assets/list' (HTTP GET) RESPONSE:

[{
    src: 'http://img.jpg',
    //type: 'image',  //image is default
    height: 300,
    width: 200,
},{
    src: 'http://img2.jpg',
},{
    src: 'http://img3.jpg',
}]

DELETE

Parameter: delete Example: delete: 'https://my-site/assets/delete/{name}' (HTTP DELETE) RESPONSE:

{
    success: true/false,
    message: 'Some message here'
}

Can you please help me understand how to do this? I can't find documentation for the above.. except for upload, but I haven't tried that yet.