diff --git a/website/src/controllers/api-v2/groups.js b/website/src/controllers/api-v2/groups.js
index de4d21022c..5f840c4330 100644
--- a/website/src/controllers/api-v2/groups.js
+++ b/website/src/controllers/api-v2/groups.js
@@ -1101,6 +1101,7 @@ api.questLeave = function(req, res, next) {
     });
 }
 
+// TODO port to api v3? in tojson?
 function _purgeFlagInfoFromChat(group, user) {
   group.chat = _.filter(group.chat, function(message) { return !message.flagCount || message.flagCount < 2; });
   _.each(group.chat, function (message) {
diff --git a/website/src/controllers/api-v3/groups.js b/website/src/controllers/api-v3/groups.js
index 0373d02984..8f96cc09ae 100644
--- a/website/src/controllers/api-v3/groups.js
+++ b/website/src/controllers/api-v3/groups.js
@@ -567,7 +567,7 @@ function _inviteByEmails (emails, group, inviter, req, res, next) {
  *
  * @apiSuccess {Object} empty An empty object
  */
-/* api.inviteToGroup = {
+api.inviteToGroup = {
   method: 'POST',
   url: '/groups/:groupId/invite',
   middlewares: [authWithHeaders(), cron],
@@ -598,6 +598,6 @@ function _inviteByEmails (emails, group, inviter, req, res, next) {
     })
     .catch(next);
   },
-};*/
+};
 
 export default api;
diff --git a/website/src/models/group.js b/website/src/models/group.js
index fd79686977..95f5a82b94 100644
--- a/website/src/models/group.js
+++ b/website/src/models/group.js
@@ -94,16 +94,6 @@ schema.statics.sanitizeUpdate = function sanitizeUpdate (updateObj) {
   }
 }*/
 
-// FIXME this isn't always triggered, since we sometimes use update() or findByIdAndUpdate()
-// @see https://github.com/LearnBoost/mongoose/issues/964 -> Add update pre?
-// TODO necessary?
-schema.pre('save', function preSaveGroup (next) {
-  // removeDuplicates(this);
-  this.memberCount = _.size(this.members);
-  this.challengeCount = _.size(this.challenges);
-  return next();
-});
-
 // TODO test
 schema.pre('remove', true, function preRemoveGroup (next, done) {
   next();
@@ -135,24 +125,6 @@ schema.post('remove', function postRemoveGroup (group) {
   firebase.deleteGroup(group._id);
 });
 
-/* schema.methods.toJSON = function groupToJSON () {
-  let doc = this.toObject();
-  // removeDuplicates(doc);
-  doc._isMember = this._isMember; // TODO ?
-
-  // TODO migration
-  // fix(groups): temp fix to remove chat entries stored as strings (not sure why that's happening..).
-  // Required as angular 1.3 is strict on dupes, and no message.id to `track by`
-  _.remove(doc.chat, msg => !msg.id);
-
-  // TODO should not be needed here
-  // @see pre('save') comment above
-  this.memberCount = _.size(this.members);
-  this.challengeCount = _.size(this.challenges);
-
-  return doc;
-};*/
-
 // TODO populate (invites too), isMember?
 schema.statics.getGroup = function getGroup (user, groupId, fields) {
   let query;
@@ -170,7 +142,7 @@ schema.statics.getGroup = function getGroup (user, groupId, fields) {
     .select(fields)
     .exec(); // TODO catch errors here?
 
-    // TODO purge chat flags info?
+    // TODO purge chat flags info? in tojson?
 };
 
 // TODO move to its own model