Updated for ember-cli 1.13.8 To add handlebar helper, create file under 'app/helpers/' directory If your helper name is 'if-first' than your file will be like 'app/helpers/if-first.js' Remember to use dash in helper name so that it will be loaded automatically, for more info read http://www.ember-cli.com/#resolving-handlebars-helpers . Example: Check for first element in each loop. 'app/helpers/if-first.js' import Ember from "ember" export default Ember.Helper.helper(function(options) { if(options[0] === 0){ return options[1]; }else{ return options[2]; } }; then use it in your handlebars template {{#each items as |item index|}} <div class={{if-first index "active item" "item"}}> </div> {{/each}} You can also pass parameter to helpers like: {{#format-date date}} and collect...