Could you tell me which file or files notes are stored in in %appdata%? I’d like to try indexing them so that they show up in general searches.
Notes are stored in your project (*.tpy) files which are in SQLite 3 format.
As @flachware says, all notes are stored in the project database. Notes are stored using an internal document model (they’re converted to HTML, Markdown, or similar at the application level) but also as plain-text (specifically for indexing purposes). For this reason it’s quite easy to extract the note text contents, but if you’re indexing this outside of Tropy all notes will still point to project file.
What might be more useful, is to extract the notes and the item and photo ids. With this, you could create
tropy:// URLs for each note. Opening such a URL would start Tropy, showing the corresponding note. Currently, Tropy URLs all operate on the most recently used project file but we’re going to add an option to add project files using a full path or name alias soon. Do you think this would be an option for you? That is, you could index each note content to a URL which opens the note in Tropy.