diff --git a/scripts-available/CDB_Groups.sql b/scripts-available/CDB_Groups.sql
index 41687fa..cdc771a 100644
--- a/scripts-available/CDB_Groups.sql
+++ b/scripts-available/CDB_Groups.sql
@@ -50,37 +50,45 @@ BEGIN
 END
 $$ LANGUAGE PLPGSQL VOLATILE;
 
--- Adds a user to a group
+-- Adds users to a group
 CREATE OR REPLACE
-FUNCTION cartodb.CDB_Group_AddMember(group_name text, username text)
+FUNCTION cartodb.CDB_Group_AddUsers(group_name text, usernames text[])
     RETURNS VOID AS $$
 DECLARE
     group_role TEXT;
     user_role TEXT;
+    username TEXT;
 BEGIN
     group_role := cartodb._CDB_Group_GroupRole(group_name);
-    user_role := cartodb._CDB_User_RoleFromUsername(username);
-    IF(group_role IS NULL OR user_role IS NULL)
-    THEN
-      RAISE EXCEPTION 'Group role (%) and user role (%) must be already existing', group_role, user_role;
-    END IF;
-    EXECUTE format('GRANT %I TO %I', group_role, user_role);
-    PERFORM cartodb._CDB_Group_AddMember_API(group_name, username);
+    foreach username in array usernames
+    loop
+      user_role := cartodb._CDB_User_RoleFromUsername(username);
+      IF(group_role IS NULL OR user_role IS NULL)
+      THEN
+        RAISE EXCEPTION 'Group role (%) and user role (%) must be already existing', group_role, user_role;
+      END IF;
+      EXECUTE format('GRANT %I TO %I', group_role, user_role);
+    end loop;
+    PERFORM cartodb._CDB_Group_AddUsers_API(group_name, usernames);
 END
 $$ LANGUAGE PLPGSQL VOLATILE;
 
--- Removes a user from a group
+-- Removes users from a group
 CREATE OR REPLACE
-FUNCTION cartodb.CDB_Group_RemoveMember(group_name text, username text)
+FUNCTION cartodb.CDB_Group_RemoveUsers(group_name text, usernames text[])
     RETURNS VOID AS $$
 DECLARE
     group_role TEXT;
     user_role TEXT;
+    username TEXT;
 BEGIN
     group_role := cartodb._CDB_Group_GroupRole(group_name);
-    user_role := cartodb._CDB_User_RoleFromUsername(username);
-    EXECUTE format('REVOKE %I FROM %I', group_role, user_role);
-    PERFORM cartodb._CDB_Group_RemoveMember_API(group_name, username);
+    foreach username in array usernames
+    loop
+      user_role := cartodb._CDB_User_RoleFromUsername(username);
+      EXECUTE format('REVOKE %I FROM %I', group_role, user_role);
+    end loop;
+    PERFORM cartodb._CDB_Group_RemoveUsers_API(group_name, usernames);
 END
 $$ LANGUAGE PLPGSQL VOLATILE;
 
diff --git a/scripts-available/CDB_Groups_API.sql b/scripts-available/CDB_Groups_API.sql
index 5287802..136a969 100644
--- a/scripts-available/CDB_Groups_API.sql
+++ b/scripts-available/CDB_Groups_API.sql
@@ -5,6 +5,12 @@
 -- Requires configuration parameter. Example: SELECT cartodb.CDB_Conf_SetConf('groups_api', '{ "host": "127.0.0.1", "port": 3000, "timeout": 10, "username": "extension", "password": "elephant" }');
 ----------------------------------
 
+-- TODO: delete this development cleanup before final merge
+DROP FUNCTION IF EXISTS cartodb.CDB_Group_AddMember(group_name text, username text);
+DROP FUNCTION IF EXISTS cartodb.CDB_Group_RemoveMember(group_name text, username text);
+DROP FUNCTION IF EXISTS cartodb._CDB_Group_AddMember_API(group_name text, username text);
+DROP FUNCTION IF EXISTS cartodb._CDB_Group_RemoveMember_API(group_name text, username text);
+
 -- Sends the create group request
 CREATE OR REPLACE
 FUNCTION cartodb._CDB_Group_CreateGroup_API(group_name text, group_role text)
@@ -45,27 +51,28 @@ $$
 $$ LANGUAGE 'plpythonu' VOLATILE SECURITY DEFINER;
 
 CREATE OR REPLACE
-FUNCTION cartodb._CDB_Group_AddMember_API(group_name text, username text)
+FUNCTION cartodb._CDB_Group_AddUsers_API(group_name text, usernames text[])
     RETURNS VOID AS
 $$
     import string
     import urllib
 
     url = '/api/v1/databases/{0}/groups/%s/users' % (urllib.pathname2url(group_name))
-    body = '{ "username": "%s" }' % username
+    body = "{ \"users\": [\"%s\"] }" % "\",\"".join(usernames)
     query = "select cartodb._CDB_Group_API_Request('POST', '%s', '%s', '{200, 409}') as response_status" % (url, body)
     plpy.execute(query)
 $$ LANGUAGE 'plpythonu' VOLATILE SECURITY DEFINER;
 
 CREATE OR REPLACE
-FUNCTION cartodb._CDB_Group_RemoveMember_API(group_name text, username text)
+FUNCTION cartodb._CDB_Group_RemoveUsers_API(group_name text, usernames text[])
     RETURNS VOID AS
 $$
     import string
     import urllib
 
-    url = '/api/v1/databases/{0}/groups/%s/users/%s' % (urllib.pathname2url(group_name), username)
-    query = "select cartodb._CDB_Group_API_Request('DELETE', '%s', '', '{200, 404}') as response_status" % url
+    url = '/api/v1/databases/{0}/groups/%s/users' % (urllib.pathname2url(group_name))
+    body = "{ \"users\": [\"%s\"] }" % "\",\"".join(usernames)
+    query = "select cartodb._CDB_Group_API_Request('DELETE', '%s', '%s', '{200, 404}') as response_status" % (url, body)
     plpy.execute(query)
 $$ LANGUAGE 'plpythonu' VOLATILE SECURITY DEFINER;
 
diff --git a/test/organization/test.sh b/test/organization/test.sh
index 56a5b0d..7e54307 100644
--- a/test/organization/test.sh
+++ b/test/organization/test.sh
@@ -187,7 +187,7 @@ function setup() {
     sql "SELECT cartodb.CDB_Group_CreateGroup('group_a_tmp')"
     sql "SELECT cartodb.CDB_Group_RenameGroup('group_a_tmp', 'group_a')"
 
-    sql "SELECT cartodb.CDB_Group_AddMember('group_a', 'cdb_testmember_1')"
+    sql "SELECT cartodb.CDB_Group_AddUsers('group_a', ARRAY['cdb_testmember_1'])"
 
     sql "SELECT cartodb.CDB_Group_CreateGroup('group_b')"
 }
@@ -203,7 +203,7 @@ function tear_down() {
 
     sql "select cartodb.CDB_Group_DropGroup('group_b')"
 
-    sql "SELECT cartodb.CDB_Group_RemoveMember('group_a', 'cdb_testmember_1')"
+    sql "SELECT cartodb.CDB_Group_RemoveUsers('group_a', ARRAY['cdb_testmember_1'])"
 
     sql "select cartodb.CDB_Group_DropGroup('group_a')"
     sql "SELECT cartodb.CDB_Organization_RemoveAdmin('cdb_org_admin');"
@@ -474,8 +474,8 @@ function test_group_management_functions_cant_be_used_by_normal_members() {
     sql cdb_testmember_1 "SELECT cartodb.CDB_Group_CreateGroup('group_x_1');" fails
     sql cdb_testmember_1 "SELECT cartodb.CDB_Group_RenameGroup('group_a', 'group_x_2');" fails
     sql cdb_testmember_1 "SELECT cartodb.CDB_Group_DropGroup('group_a');" fails
-    sql cdb_testmember_1 "SELECT cartodb.CDB_Group_AddMember('group_a', 'cdb_testmember_2');" fails
-    sql cdb_testmember_1 "SELECT cartodb.CDB_Group_RemoveMember('group_a', 'cdb_testmember_1');" fails
+    sql cdb_testmember_1 "SELECT cartodb.CDB_Group_AddUsers('group_a', ARRAY['cdb_testmember_2']);" fails
+    sql cdb_testmember_1 "SELECT cartodb.CDB_Group_RemoveUsers('group_a', ARRAY['cdb_testmember_1']);" fails
 }
 
 function test_group_permission_functions_cant_be_used_by_normal_members() {
@@ -496,8 +496,8 @@ function test_group_permission_functions_cant_be_used_by_normal_members() {
 function test_group_management_functions_can_be_used_by_org_admin() {
     sql cdb_org_admin "SELECT cartodb.CDB_Group_CreateGroup('group_x_tmp');"
     sql cdb_org_admin "SELECT cartodb.CDB_Group_RenameGroup('group_x_tmp', 'group_x');"
-    sql cdb_org_admin "SELECT cartodb.CDB_Group_AddMember('group_x', 'cdb_testmember_1');"
-    sql cdb_org_admin "SELECT cartodb.CDB_Group_RemoveMember('group_x', 'cdb_testmember_1');"
+    sql cdb_org_admin "SELECT cartodb.CDB_Group_AddUsers('group_x', ARRAY['cdb_testmember_1', 'cdb_testmember_2']);"
+    sql cdb_org_admin "SELECT cartodb.CDB_Group_RemoveUsers('group_x', ARRAY['cdb_testmember_1', 'cdb_testmember_2']);"
     # TODO: workaround superadmin limitation
     sql "SELECT cartodb.CDB_Group_DropGroup('group_x');"
 }