Other than save_post any other actions on add / edit post screen?

When the add post or edit post screens load, is there an action other than save_post which I can hook on to? I need to make an API request before a user starts adding / editing posts. Basically when the add or edit post screen loads I need my API call to be made. I know that save_post first when those pages are loaded, i'm just wondering if there is an earlier action I can hook on to? I've looked at http://ift.tt/GRkRM6 and do not see any useful other than save_post

Thanks