[feat] Add Letterboxd as a sync provider

[kstenqvist]

Problem to solve

Many users track what they watch and how they rate movies in Letterboxd, while actually watching the content in Plex.

Without Letterboxd support, watch history and ratings quickly drift out of sync. Users either have to log everything manually in multiple places or accept that one platform is always incomplete.

Given how common Letterboxd is as a personal movie diary, the lack of integration feels like a missing core use case.

Proposal

Add Letterboxd as a sync provider with support for:

• Watch history sync (including watched date when available)
• Star ratings sync (including half stars)
• One-way or two-way sync
• Basic conflict handling (e.g. prefer Letterboxd, prefer Plex, or latest update wins)

Matching could primarily rely on TMDB/IMDb IDs, with title + year as fallback.

Even a simple initial implementation (e.g. one-way sync) would be extremely valuable for many users.

Area

• Watchlist
• Ratings
• History
• Playlists
• Scrobble watcher
• Scheduler
• Web UI
• Config/API

[cenodude]

I get this request a lot, but here’s the problem: Letterboxd doesn’t offer public API access. Without an API, there’s nothing I can integrate or sync, so I can’t support it.

[kstenqvist]

Is it possible to use their API beta? https://letterboxd.com/api-beta/

[cenodude]

No, im afraid not. That’s for private API access only, and they’re pretty clear they don’t grant it for personal projects.
For CrossWatch to work properly, every Letterboxd user would need their own API access.

The only thing Letterboxd provides is:

If you require your account data in a machine-readable format, we provide import and export facilities.

So the practical route is export/import. CrossWatch already supports exporting in a Letterboxd compatible format, which is exactly what their official option enables.

If Letterboxd ever offers a public, per-user API, again, I’ll gladly add support for it.
For now, use the exporter, or switch to SIMKL/TRAKT. In my humbe opinion: SIMKL’s free tier is really good.

[kstenqvist]

Okey, that makes sense. Thanks for the update! Fingers crossed for an API in the future, until then I'll use the export/import option :) I'll make sure to check out SIMKL!

[cenodude]

I wouldn’t count on it, their API has been in “private beta” since 2018.
So I doubt it’ll ever happen, but hey, you never know 100%. 😄

[bdougherty]

What about using the RSS feed? When you add a movie to the diary, it will have an entry that gives the tmdb id and your star rating for that movie. Maybe it could be used to at least remove movies from the watch list on other services?

[cenodude]

What about using the RSS feed? When you add a movie to the diary, it will have an entry that gives the tmdb id and your star rating for that movie. Maybe it could be used to at least remove movies from the watch list on other services?

RSS feeds aren’t reliable enough for syncing. They’re often cached, and you can’t run proper health checks against them. Worst case: the feed returns zero items for a moment, your sync thinks that’s real, and deletes everything on the destination. You really don’t want that. 🙂

For a one-way sync with Letterboxd, the only workaround/hack is to simulate browser actions against Letterboxd. That’s already a pain (2FA, rate limits, random UI changes), and it’s also not allowed: Letterboxd’s ToS explicitly forbids using “any robot, spider, scraper… or other automated data gathering/extraction tool” unless they’ve explicitly authorized it.

Unless Letterboxd changes (offers a proper API or explicitly authorizes automation) there is just no way that i will integrate it.

There are a few projects that offer syncing, like treysu/letterboxd-plex-sync, but they’re clear about the trade-off: it works by scraping (simulating Letterboxd browser actions) and they state clearly: Use this tool responsibly and at your own risk, as it is unknown if this could result in account restrictions