Thank you so much for the information! My workflow proceeds as follows: PPro passes the video to my system ---> user manipulates and modifies video on my system's UI ---> my system passes the rerended video back to PPro. Also, I have a few other questions. Firstly, can you direct me to the official ExtendScript API? And secondly, is ExtendScript used for building the host server or is it used on the PPro side? Thank you!