Sample helper package

helper.js

MyObject = {};

/**
 * Common functions
 */

MyObject.common = function() {};

/**
 * Client only
 */
if (Meteor.isClient) {
  MyObject.client = function() {};
}

/**
 * Server only
 */
if (Meteor.isServer) {
  MyObject.server = function() {};
}

package.js

Package.onUse(function(api) {
  api.versionsFrom('1.1.0.2');


  /**
   * Common must be loaded first.
   */
  api.addFiles('helper.js');

  api.export('MyObject');
});