/* the key must match an existing API method */
myCustomApiMethod(/* arguments of the original method */) {
return new Promise((resolve) => {
resolve(myCustomResponse);
/* Use a custom API on the entire SDK instance */
var appmixer = new Appmixer({ api: myCustomApi });
/* Use a custom API on a particular SDK UI widget */
var designer = new appmixer.ui.Designer({ api: myCustomApi });