diff --git a/website/src/controllers/api-v3/quests.js b/website/src/controllers/api-v3/quests.js
index 05f4a69223..13584b139c 100644
--- a/website/src/controllers/api-v3/quests.js
+++ b/website/src/controllers/api-v3/quests.js
@@ -35,7 +35,7 @@ let api = {};
  *
  * @apiParam {string} groupId The group _id (or 'party')
  *
- * @apiSuccess {Object} Quest Object
+ * @apiSuccess {Object} quest Quest Object
  */
 api.inviteToQuest = {
   method: 'POST',
@@ -124,4 +124,58 @@ api.inviteToQuest = {
   },
 };
 
+/**
+ * @api {post} /groups/:groupId/quests/accept Accept a pending quest
+ * @apiVersion 3.0.0
+ * @apiName AcceptQuest
+ * @apiGroup Group
+ *
+ * @apiParam {string} groupId The group _id (or 'party')
+ *
+ * @apiSuccess {Object} quest Quest Object
+ */
+api.acceptQuest = {
+  method: 'POST',
+  url: '/groups/:groupId/quests/accept',
+  middlewares: [authWithHeaders(), cron],
+  async handler (req, res) {
+    let user = res.locals.user;
+
+    req.checkParams('groupId', res.t('groupIdRequired')).notEmpty();
+
+    let validationErrors = req.validationErrors();
+    if (validationErrors) throw validationErrors;
+
+    let group = await Group.getGroup({user, groupId: req.params.groupId, fields: 'type quest'});
+
+    if (!group) throw new NotFound(res.t('groupNotFound'));
+    if (group.type !== 'party') throw new NotAuthorized(res.t('guildQuestsNotSupported'));
+    if (!group.quest.key) throw new NotFound(res.t('questInviteNotFound'));
+
+    group.quest.members[user._id] = true;
+    user.party.quest.RSVPNeeded = false;
+
+    if (canStartQuestAutomatically(group)) {
+      await group.startQuest(user);
+    }
+
+    let [savedGroup] = await Q.all([
+      group.save(),
+      user.save(),
+    ]);
+
+    res.respond(200, savedGroup.quest);
+
+    // track that an user has accepted the quest
+    analytics.track('quest', {
+      category: 'behavior',
+      owner: false,
+      response: 'accept',
+      gaLabel: 'accept',
+      questName: group.quest.key,
+      uuid: user._id,
+    });
+  },
+};
+
 export default api;
diff --git a/website/src/models/group.js b/website/src/models/group.js
index 4046b7d5ee..ff7a22b63c 100644
--- a/website/src/models/group.js
+++ b/website/src/models/group.js
@@ -170,6 +170,57 @@ schema.methods.isMember = function isGroupMember (user) {
   }
 };
 
+export function chatDefaults (msg, user) {
+  let message = {
+    id: shared.uuid(),
+    text: msg,
+    timestamp: Number(new Date()),
+    likes: {},
+    flags: {},
+    flagCount: 0,
+  };
+
+  if (user) {
+    _.defaults(message, {
+      uuid: user._id,
+      contributor: user.contributor && user.contributor.toObject(),
+      backer: user.backer && user.backer.toObject(),
+      user: user.profile.name,
+    });
+  } else {
+    message.uuid = 'system';
+  }
+
+  return message;
+}
+
+schema.methods.sendChat = function sendChat (message, user) {
+  this.chat.unshift(chatDefaults(message, user));
+  this.chat.splice(200);
+
+  // Kick off chat notifications in the background. // TODO refactor
+  let lastSeenUpdate = {$set: {}, $inc: {_v: 1}};
+  lastSeenUpdate.$set[`newMessages.${this._id}`] = {name: this.name, value: true};
+
+  if (this._id === 'habitrpg') {
+    // TODO For Tavern, only notify them if their name was mentioned
+    // var profileNames = [] // get usernames from regex of @xyz. how to handle space-delimited profile names?
+    // User.update({'profile.name':{$in:profileNames}},lastSeenUpdate,{multi:true}).exec();
+  } else {
+    let query = {};
+
+    if (this.type === 'party') {
+      query['party._id'] = this._id;
+    } else {
+      query.guilds = this._id;
+    }
+
+    query._id = { $ne: user ? user._id : ''};
+
+    User.update(query, lastSeenUpdate, {multi: true}).exec();
+  }
+};
+
 schema.methods.startQuest = async function startQuest (user) {
   // not using i18n strings because these errors are meant for devs who forgot to pass some parameters
   if (this.type !== 'party') throw new InternalServerError('Must be a party to use this method');
@@ -249,57 +300,6 @@ schema.methods.startQuest = async function startQuest (user) {
   });
 };
 
-export function chatDefaults (msg, user) {
-  let message = {
-    id: shared.uuid(),
-    text: msg,
-    timestamp: Number(new Date()),
-    likes: {},
-    flags: {},
-    flagCount: 0,
-  };
-
-  if (user) {
-    _.defaults(message, {
-      uuid: user._id,
-      contributor: user.contributor && user.contributor.toObject(),
-      backer: user.backer && user.backer.toObject(),
-      user: user.profile.name,
-    });
-  } else {
-    message.uuid = 'system';
-  }
-
-  return message;
-}
-
-schema.methods.sendChat = function sendChat (message, user) {
-  this.chat.unshift(chatDefaults(message, user));
-  this.chat.splice(200);
-
-  // Kick off chat notifications in the background. // TODO refactor
-  let lastSeenUpdate = {$set: {}, $inc: {_v: 1}};
-  lastSeenUpdate.$set[`newMessages.${this._id}`] = {name: this.name, value: true};
-
-  if (this._id === 'habitrpg') {
-    // TODO For Tavern, only notify them if their name was mentioned
-    // var profileNames = [] // get usernames from regex of @xyz. how to handle space-delimited profile names?
-    // User.update({'profile.name':{$in:profileNames}},lastSeenUpdate,{multi:true}).exec();
-  } else {
-    let query = {};
-
-    if (this.type === 'party') {
-      query['party._id'] = this._id;
-    } else {
-      query.guilds = this._id;
-    }
-
-    query._id = { $ne: user ? user._id : ''};
-
-    User.update(query, lastSeenUpdate, {multi: true}).exec();
-  }
-};
-
 function _cleanQuestProgress (merge) {
   // TODO clone? (also in sendChat message)
   let clean = {