So I coded:

Code:
Ext.Loader.setConfig({ enabled: true });
Ext.require(['Ext.direct.*']);

Ext.application( {
    name: 'MyApp',
    
    requires: ['MyApp.store.User'],
    models: ['User'],    
    stores: ['User'],
    controllers: ['User'],
    autoCreateViewport: true,
    
    launch: function() {
        Ext.direct.Manager.addProvider( Ext.app.REMOTING_API );
    }
});
In Firefox Webconsole the lines after loading "/api/src" are:
"GET http://...app/store/user.js.."
"GET http://...app/model/user.js.."
"DBICUser is not defined".

If I comment out the models, stores and controllers lines, the undefined error occurs now after the "GET view/Viewport.js" line.

The Store looks like this now:
Code:
Ext.define('MyApp.store.User', {
    extend: 'Ext.data.Store',   
    model: 'MyApp.model.User',
    autoLoad: true,
    constructor : function(config) {
        Ext.applyIf(config, {
            proxy : {
                type : 'direct',
                directFn : DBICUser.list,
                reader : {
                    type : 'json',
                    root : 'list'
                }
            }
        });

        this.callParent([config]);
    }
});
The model just holds

Code:
Ext.define("Blubberlog.model.Ansatz", {
    extend: 'Ext.data.Model',

    fields: [...],
    idProperty:"id_user",
    associations: [ ... ]
});
Do I have to load something else than "ext-all-debug.js" ?