Map of additional parameter to submit to remote data source. Adding properties to .postData object will instruct the form to submit these parameters to the remote data source with each remote request (get, save). You can defined it during object creation: let form = new w2form({ name : 'form', url : '/server/url', formURL : '/server/path', fields: [ { field: 'first_name', type: 'text', required: true }, { field: 'last_name', type: 'text', required: true }, { field: 'email', type: 'email' } ], record: { first_name : 'John', last_name : 'Doe', email : 'jdoe@email.com' }, actions: { "save": function () { this.validate(); }, "reset": function () { this.clear(); } }, postData: { param1 : 'value1', param2 : 'value2' } }); Or any time during the run-time.