Remote sessions can load skills from a host skill catalog via CLAUDE_CODE_HOST_SKILL_CATALOG

What

Skills are packaged instructions Claude can load for particular tasks. Claude Code gains a new place to get them from: a catalog supplied by the host, the program or service running the session.

• CLAUDE_CODE_HOST_SKILL_CATALOG: a new environment variable (a setting passed in from outside the program), absent from the previous build. Its value must be JSON of the form {"skills": [...]} with 1 to 64 folder names made of ASCII letters, digits, ., _ or -. An invalid value is ignored with a warning. The result is a set of allowed skill names that the skill list is filtered against.
• It is picked up only in a remote session (when CLAUDE_CODE_REMOTE_SESSION_ID is set) that is not a child session, and the variable is then removed from the environment.
• A path constant changed from a bundled file to /mnt/skills/public, so skills may now come from a folder mounted by the host.
• Skill loading includes the host catalog as an extra source, active only when a new check passes. When the check fails and a catalog is present, the catalog is recorded as held back.
• A host skill is skipped if your account already syncs a skill with the same name, or if another skills folder links to the same file.

Why

A host running Claude Code remotely can decide which skills are offered. The skip rules mean a skill your account already syncs wins over a host copy of the same name. None of this applies unless the host sets the variable.