diff --git a/src/api.ts b/src/api.ts
index e196a49..2f2e8e5 100644
--- a/src/api.ts
+++ b/src/api.ts
@@ -6,7 +6,7 @@ import {
 	getPoolsWithUser,
 	getUserByID,
 } from './data';
-import { PoolModel } from './models';
+import { GroupModel, PoolModel } from './models';
 
 export const router = Router();
 
@@ -143,15 +143,26 @@ router.post('/join_pool', async (req, res) => {
 });
 
 router.post('/group', (req, res) => {
-	// if (req.body.groupID in groups) {
-	// 	res.json({ status: 'error', error: 'already_exists' });
-	// } else {
-	// 	groups[req.body.groupID] = {
-	// 		id: req.body.groupID,
-	// 		member_ids: [],
-	// 	};
-	// 	res.json({ status: 'success' });
-	// }
+	if (req.session.accountID == null) {
+		res.status(401);
+		return res.json({ status: 'error', error: 'need_login' });
+	}
+
+	const userID = req.session.accountID;
+	const name = req.body.name;
+
+	const group = new GroupModel();
+	group.set('name', name);
+	group.set('creator_id', userID);
+	group
+		.save()
+		.then((group) => {
+			res.json({ status: 'success', id: group._id });
+		})
+		.catch((err) => {
+			console.error('Error when creating a group:', err);
+			res.json({ status: 'error' });
+		});
 });
 
 router.get('/my_pools', async (req, res) => {
diff --git a/src/models.ts b/src/models.ts
index a63f30c..39e9ec7 100644
--- a/src/models.ts
+++ b/src/models.ts
@@ -33,9 +33,10 @@ const UserModel: Model<User> = model('User', UserSchema);
 const GroupSchema: Schema = new Schema({
 	name: { type: String, required: true },
 	member_ids: { type: [String], required: true },
+	creator_id: { type: String, required: true },
 });
 
-const GroupModel = model('Group', GroupSchema);
+const GroupModel: Model<Group> = model('Group', GroupSchema);
 
 const CommentSchema: Schema = new Schema({
 	text: { type: String, required: true },