An unofficial plugin to keep your watched movie history from Jellyfin automatically updated to your Letterboxd diary.

About

This plugin keeps your Jellyfin watch history in sync with your Letterboxd diary. Since v2.0.0 it talks to Letterboxd's official REST API (api.letterboxd.com) instead of scraping the website, which removes the Cloudflare 403 errors that used to require copying cookies.

Features

• Diary sync — films you finish on Jellyfin are logged to your Letterboxd diary, either in real time (as soon as playback finishes) or via the daily catch-up task.
• Ratings — your Jellyfin personal rating (0-10) is sent as a Letterboxd star rating (0.5-5.0).
• Favorites — films favorited on Jellyfin are marked as "liked" on Letterboxd.
• Rewatches — a film played more than once is logged as a rewatch.
• Watchlist import — any public Letterboxd watchlist or list is mirrored into a Jellyfin playlist.
• Seerr auto-request (opt-in) — films on a watchlist that are missing from your library can be automatically requested in Seerr / Jellyseerr / Overseerr, on behalf of the matching Jellyfin user.
• Diary import (opt-in) — the reverse direction: films in your Letterboxd diary are marked as watched in Jellyfin.
• Resilient — API calls automatically retry rate limits (429) and server errors with exponential backoff.

Requirements

• Jellyfin ≥ 10.11.9 — earlier versions are not supported (the plugin uses an API that changed in 10.11.9).
• File Transformation plugin (optional) — needed only to inject the Letterboxd entry in the sidebar for non-admin users. Without it, admin configuration still works fine.

Installation

1. Open the dashboard in Jellyfin, then select Catalog and open Settings at the top with the ⚙️ button.

2. Click the + button and add the repository URL below, naming it whatever you like, and save.

https://raw.githubusercontent.com/Gizmo091/jellyfin-plugin-letterboxd-sync/master/manifest.json

3. Go back to Catalog, click on 'LetterboxdSync' in the 'General' group and install the most recent version.

4. Restart Jellyfin, then go to the plugin settings (My Plugins → 'LetterboxdSync') to configure.

Configure

• You can associate one Letterboxd account with each Jellyfin user. Click Save for each one.

• Sign in with your Letterboxd username (the one in letterboxd.com/<username>/), not your email address — Letterboxd no longer allows sign-in by email. Enter your username and password once; the plugin exchanges them for a token and never stores your password.

• The daily catch-up task runs every 24 hours, only for accounts marked as Enable.

• Real-time Sync (on by default) logs a film to Letterboxd the moment you finish watching it, so you don't have to wait for the daily task. The daily task still runs as a safety net — logging is idempotent, so nothing is duplicated.

• Check Send Favorite if you want films marked as favorites on Jellyfin to also be marked as favorites on Letterboxd.

• Send Rating (on by default) sends your Jellyfin personal rating as a Letterboxd star rating. Because Letterboxd only records a rating when a film is first logged, this never overwrites a rating you set on Letterboxd afterwards.

• Import Diary (off by default) does the reverse: it reads your Letterboxd diary once a day and marks the matching films as watched in Jellyfin (using the diary date). It only ever marks films you haven't already watched in Jellyfin.

• Seerr auto-request (off by default): set a Seerr URL and API key in the admin plugin settings, then tick Auto-request on any watchlist. During the watchlist sync, films on that list that are missing from your library are requested in Seerr as the matching Jellyfin user (mapped via jellyfinUserId), so Seerr applies that user's own approval and quota rules. If no Seerr account maps to the user, auto-requesting is skipped for them.

• By default the plugin does a full sync to Letterboxd. Once the initial sync is done, it's advised to Enable Date Filtering with a short lookback to reduce load.

Troubleshooting

The settings page spins forever, or returns a 500

If you also run Jellyscribe, upgrade to v2.2.0 or later.

Jellyscribe grew out of the same original codebase as this plugin and declares its types in the same LetterboxdSync namespace. Jellyfin caches XML serializers in one dictionary shared by every loaded plugin, keyed by the type's full name — so whichever plugin loaded first had its serializer handed to the other one, and GET /Plugins/{guid}/Configuration failed with:

System.InvalidCastException: [A]LetterboxdSync.Configuration.PluginConfiguration
cannot be cast to [B]LetterboxdSync.Configuration.PluginConfiguration

Since v2.2.0 this plugin lives under Jellyfin.Plugin.LetterboxdSync, so the two can be enabled side by side. Details in #7.

Before v2.1.1 this surfaced as an endless loading spinner with no error at all, which is why upgrading is worth it even if you don't run Jellyscribe.

Upgrading

To 2.2.0

• Your accounts and settings carry over — the update itself does not touch them.
• If you were hit by the Jellyscribe conflict above, you may have to sign in to Letterboxd once more. That is not caused by the update: the failed save truncated LetterboxdSync.xml while the conflict was active, which can wipe the stored token. Re-enter the account password in the plugin settings and it re-links.
• The plugin's three scheduled tasks get new internal ids, because Jellyfin derives them from the type name. If you customised when they run, set those schedules again under Scheduled Tasks; the sync itself is unaffected.

From 1.x

• No more cookies. The Raw Cookies / Cloudflare workaround is gone — you can clear that field. Just make sure you sign in with your username (not email).
• Existing configurations keep working: on the next sync the plugin swaps your stored password for a refresh token automatically.