Metadata requests for Extras, ie plex/metadata/show-id/extras

Developing my Custom Provider Agent and want to accommodate the “/extras“ on a show request.

I think I understand the placing of all the files in each level (show/season/episode) from here Local Files for TV Show Trailers and Extras | Plex Support

My question is what responses should I be sending hierarchy etc to enable matching between the files on the server and the metadata i’m sending back.

There isn’t any documentation about it (similar to /images in the API documentation). But a call is being made (although only on the show level as I only have the desktop to test against at moment) so assume it’s supported but don’t really know what to send back.

Is this currently ‘supported’ in the Custom Provider Agents, ie it’s call and I receive a request but as there is no documentation (from what I can see) does it mean we can’t utilise it? yet?

I would love to add proper extras to shows, seasons, episodes (though some levels not supported), my fallback it to create whole new ‘shows’ as it were for extras but I’d like to have the extras show up next to the actual shows rather than have to go to a separate ‘show’. Not sure if that makes sense!!! But it’s a bad work around.