Repertoire builder
Pick the lines you want to play with White and the defences you meet as Black, then train the whole thing as one connected repertoire.
Rather than memorising a published book, you pick the lines you expect to meet. Choose a system against each defence, and it all slots together into one repertoire that you train the same way as any official course.
Each opening in the repertoire is a link to a line you can edit or replace later, so your repertoire grows with your play rather than being a one-off purchase.
A repertoire is not a flat list. When an opponent deviates, you branch the line and add the sidelines you need to cover. The trainer follows the branch, so you are always practising the move that came next in your actual games, not a book line you never saw.
Your repertoire sits in the same place as the official courses, and shows the same per-line progress bar. You get the same spaced reminders, the same recall checks, and the same option to train as White or Black.
Yes. A private repertoire stays yours and is never shown in community browse. You can make individual courses public later, or share a read-only copy with a link.
A PGN file is a record. A repertoire here is linked, editable, and tied to the trainer so it feeds directly into practice. Move a line and the drill moves with it.