Plex is the best way to manage your personal media library, and I love using Letterboxd to keep track of movies that I enjoyed. Since there was no way to connect these two services easily, I built this one. This tool uses Puppeteer on the server to log in to your Letterboxd account.
To get started, login using your Plex account on the app. After logging in, you'll need to connect your Letterboxd account. Your credentials are hashed and stored securely.
After connecting your account, add a new webhook to your Plex account (requires Plex Pass). Use the following URL: https://plex-scrobble.jwie.be/webhook
You can manage which events you want to be handled. The app currently supports media.scrobble and media.rate. You can also disable scrobbling for non-film content.
Source code is available on GitHub.