angularjs - "Error: No default engine was specified" - Only sending json -

i keep getting error, , don't understand why. not running res.render anywhere, , have no view engine specified (do not need one), doing routing front end angular.

here making simple request logged in user:

controller.js

angular.module('myapp').controller('admincontroller',   ['$scope', '$http',   function ($scope, $http) {     $http.get('/api/user')       .then(function(response){         $scope.user = response.data;       }); }]); 

and on backend, here route returns json:

api.js

router.get('/api/user', function(req, res) {     var session = req.session;     var user = db.user.findbyid(session.passport.user, function(err, user){         console.log(user);         res.json(user);     }); }); 

in browser console, getting errors saying cannot http://localhost:3000/api/user 500 (internal server error), , cli saying no default engine specified , no extension provided.

why, if returning json, express asking view engine?

you can set view engine :

app.set('view engine', 'html');  

or

app.set('view engine', 'ejs');