Autocomplete with $resource

var app = angular.module('plunker', ['ngTagsInput', 'ngResource']);

app.controller('MainCtrl', function($scope, $resource) {
  var tags = $resource('tags.json');
  
  $scope.tags = [
    { text: 'Tag1' },
    { text: 'Tag2' },
    { text: 'Tag3' }
  ];
   
  $scope.loadTags = function(query) {
    return tags.query().$promise;
  };
});

<!DOCTYPE html>
<html ng-app="plunker">

  <head>
    <meta charset="utf-8" />
    <title>AngularJS Plunker</title>
    <script>document.write('<base href="' + document.location + '" />');</script>
    <link rel="stylesheet" href="http://mbenford.github.io/ngTagsInput/css/ng-tags-input.min.css" />
    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.4.2/angular.min.js"></script>
    <script src="https://code.angularjs.org/1.2.28/angular-resource.min.js"></script>
    <script src="http://mbenford.github.io/ngTagsInput/js/ng-tags-input.min.js"></script>
    
    <script src="app.js"></script>
  </head>

  <body ng-controller="MainCtrl">
    <tags-input ng-model="tags">
      <auto-complete source="loadTags($query)"></auto-complete>
    </tags-input>
    <p>Model: {{tags}}</p>
  </body>

</html>

[
  { "text": "Tag1" },
  { "text": "Tag2" },
  { "text": "Tag3" },
  { "text": "Tag4" },
  { "text": "Tag5" },
  { "text": "Tag6" },
  { "text": "Tag7" },
  { "text": "Tag8" },
  { "text": "Tag9" },
  { "text": "Tag10" }
]