Using mers with backbone.js

I've got a rest service running with mers (https://github.com/jspears/mers).

Now I'd like to connect it to backbone.js

The problem is that mers returns the collection wrapped in a payload array with additonal info:

e.g.

{"payload":[
{"_id":"4fe3773ffca7f74410000001","pos":[48.123447013691425,11.57250838808296],"username":"AyKarsi","pictures":[],"images":[],"roles":[],"meta":{},"groups":[]},
{"_id":"4fe3773ffca7f74410000002","pos":[0,3444],"username":"TestUpdateFromClient","pictures":[],"images":[],"roles":[],"meta":{},"groups":[]},],
"status":0,"total":5}

This info is nice to have, but how can I tell the backbone collection where it should look for the models?

You'll want to override the default parse function in Backbone.Collection.

var MyCollection = Backbone.Collection.extend({
    parse: function(models) {
        return models.payload;
    }
}

Here's the relevant documentation on the Backbone.js website.