Skip to main content

Jellyfin sidecar plugin

Alpha, in active development

Anything can change between plugin releases: settings, data, URLs, and behavior. There is no backward compatibility between plugin versions and no promised upgrade path. If an update misbehaves, uninstall the plugin, delete plugins/configurations/Foreseerr in Jellyfin's data folder, and install again. Report plugin problems in the plugin repository.

This is an optional third-party Jellyfin plugin for Jellyfin 10.11 and newer, developed in selmant/jellyfin-plugin-foreseerr. It is not in the official Jellyfin catalog. It starts a bun-compiled Foreseerr process on 127.0.0.1, reverse-proxies it at /Foreseerr, and signs the current Jellyfin Web user in without a password.

Standalone Docker and compiled binaries remain the supported ways to run Foreseerr on its own.

What you get​

  • Foreseerr UI at https://your-jellyfin/Foreseerr/, including Jellyfin servers on a subpath such as /jellyfin/Foreseerr/. Anyone signed in to Jellyfin Web in that browser can open it, including from links and bookmarks.
  • Jellyfin hostname, libraries, API key, and first admin imported from this server (setup wizard skipped)
  • Foreseerr admin rights for Jellyfin administrators. Removing administrator in Jellyfin takes back only rights the plugin granted, not ones you grant in Foreseerr.
  • Crash restart of the sidecar and a plugin page with its status and last error
  • A Foreseerr button in the Jellyfin Web header if you install File Transformation
  • Better Trakt: if that plugin is loaded and no direct Trakt app is set up, Foreseerr uses it for Trakt actions

Radarr, Sonarr, notifications, and other integrations are configured inside Foreseerr Settings. The plugin will not overwrite those.

Install​

  1. Dashboard → Plugins → Repositories → add https://selmant.github.io/jellyfin-plugin-foreseerr/manifest.json.
  2. Install Foreseerr from the catalog and restart Jellyfin. Jellyfin picks the build that matches its version.
  3. Dashboard → Plugins → Foreseerr: set Public Jellyfin URL to the address people use for Jellyfin, for example https://jellyfin.example.com. Links in notifications point there. You can skip this if Jellyfin's Published Server URIs (Networking) has an all= or external= entry, or if you set Application URL in Foreseerr instead.
  4. Open Foreseerr as a Jellyfin administrator first; that account becomes the Foreseerr owner. Configure Radarr/Sonarr there.
  5. Share https://your-jellyfin/Foreseerr/ with your users, or install File Transformation for a header button.

The plugin has its own version, separate from Foreseerr's, and its releases each bundle a specific Foreseerr version, named in the release title.

To install manually, extract foreseerr-jellyfin-10.11.zip or foreseerr-jellyfin-12.zip from a plugin release into Jellyfin's plugins/Foreseerr/ folder and restart Jellyfin.

Sidecar config and SQLite live under Jellyfin plugin configuration (…/plugins/configurations/Foreseerr/foreseerr). They are kept when the plugin updates, but during the alpha a new version may not read them correctly.

How Foreseerr differs inside Jellyfin​

Foreseerr uses the Jellyfin sign-in, so a few things look different from a standalone install:

  • The user menu has Back to Jellyfin instead of Sign Out. Signing out of Jellyfin also ends the Foreseerr session.
  • Settings → Jellyfin shows that the plugin manages the server address and API key, with a link to the plugin page. Libraries and scans work as usual.
  • There are no local users, passwords, or login method settings. Settings → Users → Enable New Jellyfin Sign-In decides whether Jellyfin users who were not imported can open Foreseerr; if it is off, they see a message asking them to request access.
  • Web push notifications are not available. Use another notification agent.
  • Updates come from Dashboard → Plugins in Jellyfin.

Reverse proxies​

Forward /Foreseerr and /ForeseerrPlugin to Jellyfin like any other path. Add your proxy to Jellyfin's Known Proxies so Jellyfin sees HTTPS requests; otherwise the Foreseerr session cookie is not marked Secure.

Limits​

Jellyfin Web (desktop browser) is the supported UI. Official Android TV / mobile apps do not load this SPA. The sidecar ships for Linux (x64, arm64) and Windows (x64).

Foreseerr's own CSRF protection is off in plugin mode. The plugin replaces it: the Foreseerr session is bound to the Jellyfin login, rechecked on every request, and write requests must come from the same origin.

On the first start, Foreseerr downloads its anime mapping data and can be unresponsive for a minute or two while it stores it.

Open implementation gaps are listed in the plugin README.