The invention relates to a content management system and a method therein. The content management system comprises at least a first vault in a server and a migration tool. The method comprises receiving by the migration tool a content packet from a third-party application; receiving by the migration tool information on a metadata structure used in the first vault; generating a replication packet by adapting content from the content packet according to the information on the metadata structure; storing the replication packet in the server; and replicating the objects in the replication packet to the first vault.