Return error in request

lib/worker.js

@@ -23,10 +23,14 @@ module.exports.run = function(worker) {
   app.post('/', function(req, res) {
     if (!req.body) return res.status(404).end();
     if (!store) store = createStore(worker.options);
-    store.add(req.body).then(function(r) {
-      scServer.exchange.publish('log', req.body);
-      res.send({ id: r.id });
-    });
+
+    switch(req.body.op) {
+      default:
+        store.add(req.body).then(function(r) {
+          scServer.exchange.publish('log', req.body);
+          res.send({ id: r.id, error: r.error });
+        });
+    }
   });
 
   scServer.addMiddleware(scServer.MIDDLEWARE_EMIT, function (req, next) {