Add support for the Agent Plugins specification (plugin.json / mcp.json / skills) #1349

What problem are you trying to solve?

Google publishes agent skills and plugins for Google Cloud at google/skills. Its README says the repo "bundles Google product plugins (Skills + MCP servers) for agent harnesses" and gives each harness a direct install: claude plugin marketplace add google/skills, codex plugin marketplace add google/skills, agy plugin install <url>.

Freebuff has no equivalent. There is no plugin command in the CLI, so a spec-conformant plugin is invisible to it.

Only the skills half can be installed today, via the generic npx skills add. I verified that half works end to end in freebuff.

The plugin as a unit is unsupported: the plugin.json manifest is unread, and the mcp.json servers are never configured.

What would you like to happen?

Support the Agent Plugins spec v1.0.0 with a plugin CLI surface, for example freebuff plugins install <repo-or-path>: parse plugin.json, discover skills/ and mcp.json at the spec's fixed locations, and map mcp.json onto the native MCP config.

This is closer than it sounds. Audited against main at b0ec8028c: the skill parser is already agentskills.io-compatible, and common/src/mcp/client.ts already speaks the transports the spec requires (stdio, and Streamable HTTP).

Missing:

• manifest loading
• plugin-root discovery
• the mcp.json mapping
• PLUGIN_ROOT/PLUGIN_DATA handling
• the section 4.1 path containment

Related: #1039 asks for this kind of extensibility; #767 (closed stale) is history on bundled skill files.

Area

CLI (terminal client)

Contribution

• I would be willing to open a PR for this