Is there an API available so that I can rate movies and update my lists?

I would like to create a personal automation so that I can update my movie sites just once. For example, I'd like to be able to rate the movie Titanic and have my rating appear in both IMDB and letterboxd and added to my Movies Watched list on both sites. Is there an API or other mechanism that would allow me to do this while complying with the TOS?