ng angular typeahead drupal
OK. Its not hard. 

To achieve the same thing in angular (being served by drupal), have to:


get angular and bootstrap ui working.
create the  element in my view
add a function to the controller $scope to access $http ($http needs to be injected as a dependancy into the controller).


In my FAPI form I had a autocomplete_path defined:

 '#autocomplete_path' =&gt; 'agc/ac/contact/_',


So to access the same call back, in my Angular template:

 &lt;pre&gt;Model: {{result | json}}&lt;/pre&gt;                           
  &lt;input type="text" ng-model="result"                                           
   typeahead="suggestion for suggestion in cities($viewValue)"&gt;


The controller:

angular.module('contactFindControllers', []).controller('contactFindCtrl',
  ['$scope', '$http', function($scope, $http) {
    $scope.cities = function(cityName) {
    var path = '/agc/ac/contact/_/' + cityName;
    return $http.get(path)
    .then(function(response){
      // see note below regarding "_.values()"
      return _.values(response.data);
        });
  };

}]);


FYI: I used this as a starting point.

Note: my callback returns a JSON object (because I have non-numeric keys) not the array I needed, so I need to extract the values with _.values().
You many not need to use _.values at all (or if facing the same issue just
grab the values from the object or modify your call back to 
return a json array)