claude.ai skills can arrive as plugins, and skills replaced by a plugin point to it

What

Skills are reusable sets of instructions Claude Code can run. Plugins are add-on packages that can bundle skills and other features. Plugin sync is the step that brings plugins from your claude.ai account into Claude Code. It can now ask for skills that have been converted into plugins, and several related pieces changed:

• convertedSkillsAsPlugins: under certain session conditions, the sync asks the plugin listing to include converted skills. Results that match plugins you already have locally are listed first.
• Plugin loading now remembers which files it has already loaded (loadedPaths) and skips a file it has seen before, comparing by the file's real location on disk. The step that merges plugins together can also hold a plugin back by marking it disabled.
• hiddenBehindPlugin: a synced skill that now belongs to a plugin is hidden. Running it gives a message saying it "is now part of the plugin" and points to the plugin skill. If that plugin is turned off, the message says "Check /plugin to turn it on and run it". Hidden skills are left out of skill lists and are not counted as your own skills.
• skillOverrides, the setting that hides or collapses a skill, now applies to skills that come from plugins. Before, plugin skills were always treated as on. An organization-level lookup was added, and a skill hidden behind a plugin counts as off.
• Setting a claude.ai skill to "off" or "user-invocable-only" now also turns off the synced plugin that provides it, in your local settings. If saving that change fails, the plugin is held off each time it loads instead.
• Built-in plugins don't appear in claude plugin list. The plugin details screen and the not-found error now say so and tell you to run /plugin and open the Installed tab.

Why

If you use skills from claude.ai, some may now show up as plugins, and the old skill name will point you to the plugin instead of running. Turning a skill off in claude.ai also turns its plugin off locally, so if something seems missing, /plugin and its Installed tab are the place to look.