Both Sonarr/Radarr have this 'Connect' tab in the settings where you can specify postprocessing triggers for various other programs when a new episode/movie is downloaded/upgraded/renamed/removed. e.g.
It would be great if Bazarr came included with script(s) for both Sonarr/Radarr to be added on this tab so that when a new episode/movie is downloaded, instead of Bazarr waiting until a scheduled interval occurs, these scripts would tell Bazarr to go out and search/download the subtitles immediately after the download, much like SubZero functions in Plex.
The information about the episode/movie is passed through environment variables.
For Sonarr the info can be found here:
For Radarr the info can be found here: