Track upstream Claude Code skill portability limitations

[kdeldycke]

Repomatic manages Claude Code skills for downstream repos via repomatic init skills. These skills work in Claude Code (CLI and Desktop Code tab) but are not portable to other Claude surfaces due to multiple upstream limitations.

Skill systems

Claude has three separate skill registries that do not share state:

Surface	Discovery	Status
Claude Code (CLI + Desktop Code tab)	~/.claude/skills/ and .claude/skills/	Works. Skills auto-discovered, invocable via /. Desktop panel doesn't display them (cosmetic bug).
Desktop chat / claude.ai	Server-side container at /mnt/skills/	Broken. Upload via Customize > Skills panel is the only path. Uploaded skills register metadata in the system prompt but SKILL.md files are often not mounted on disk.
Cowork	Session container mount of project .claude/skills/	Partial. Files are readable on disk but not registered as / commands. Manual "read and follow SKILL.md" works.

Workaround

package-skills.sh packages each skill as an individual ZIP for manual upload to the Desktop Customize > Skills panel. This is the only upload path: there is no batch import, no API, and no local storage to write to (the Desktop Electron app sends ZIPs to Anthropic's servers). As of April 2026, the upload itself is unreliable due to server-side mount failures.

For Cowork, opening a project that contains .claude/skills/ exposes the skills on disk. They are not auto-registered but can be invoked by asking Cowork to read the SKILL.md file directly.

Upstream issues

All open as of 2026-04-11:

• [BUG] Skills from ~/.claude/skills/ and plugins not shown in Customize -> Skills panel anthropics/claude-code#31597 - Skills from ~/.claude/skills/ not shown in Desktop Customize > Skills panel
• Skill portability between Claude Code and Claude.ai anthropics/claude-code#37487 - Skill portability between Claude Code and claude.ai
• [FEATURE] Sync Skills between Claude Desktop and Claude Code CLI anthropics/claude-code#20697 - Sync skills between Desktop and CLI
• No native way to sync Claude Code config and skills across machines anthropics/claude-code#36693 - No native cross-machine sync for skills and config
• [BUG] User and Organization Skills — Metadata Registered in System Prompt but SKILL.md Files Not Mounted in Container anthropics/claude-code#26254 - User/org skills metadata registered but SKILL.md not mounted in container
• [BUG] Skills upload returns "Internal server error" on Claude Web and Desktop anthropics/claude-code#26310 - Skills upload returns "Internal server error"
• Cowork: skills visible in Customize but not loaded in chat (context budget) anthropics/claude-code#40774 - Cowork: skills visible in Customize but not loaded in chat

[kdeldycke]

Retested against Claude Code 2.1.220 and the current Desktop app: the "Desktop chat / claude.ai" row is out of date. A plugin now installs directly into Desktop, and its skills and agents are usable in chat.

What changed

Desktop has a Plugins panel of its own under Customize > Plugins, separate from Customize > Skills. It accepts a plugin archive through Add > Upload plugin.

I uploaded repomatic-plugin.zip from the v7.6.0 release, unmodified and with no repackaging:

• It installs as "Repomatic", enabled, carrying both a Skills tab and an Agents tab.
• The skills are listed and invocable by typing / in chat.
• Agents ship in the same upload, which the per-skill archive route never supported.

Anthropic's help center matches: plugins install in Claude web, the Desktop Chat tab, and Cowork, and "the skills bundled in a plugin work across all three". Hooks and sub-agents run only in Cowork and appear greyed out in chat.

Consequences for the table

The row reading Broken, with "Upload via Customize > Skills panel is the only path", is wrong on both counts. The plugin path works, and it delivers more than the Skills panel can accept.

.claude/package-skills.sh is superseded for the bulk case, and the "cannot be merged" rationale in its header no longer holds.

Still open

Whether Desktop can sync a marketplace rather than only accept an upload. Adding kdeldycke/dotfiles, whose plugin entry uses a "./" relative-path source, failed with a bare "Marketplace sync failed" on both the owner/repo and full-URL forms. I ruled out repository visibility, anonymous reachability, symlink loops and repository size: the same manifest adds and installs cleanly through claude plugin marketplace add, which clones over SSH and resolves the path locally. The anthropics/claude-plugins-community registry uses only remote url sources with pinned SHAs and never a relative path, so relative-path sources may not be supported app-side at all. Untested with repomatic's own archive source.

This matters because an uploaded plugin reports its source as Uploaded from file with no update channel, so every release needs a fresh upload. Working marketplace sync would remove that.

Documentation updated in docs/plugin.md.