Revision history with firebase real time database

Question

I'm the working on an online ide editor for students - codiva.io I'm planning to support collaboration and revision history, i see that firebase real time database would be great fit for this use case. Collaboration seems easy, but I couldn't find much info on whether firebase automatically maintains the revision history or if this has to be implemented separately. I assume firebase uses diffs to sync between devices and probably use operational transformation for resolving conflicts. Is it possible to capture the diffs and store separately so that I can support a consistent revision history.