Plugins

Feature plugins (off by default; implies skills, adds an async HTTP client, and runs git).

A marketplace publishes a catalog in the Claude Code marketplace.json format, such as AgentHub. Each entry points at a git repository holding the plugin. Two of the things a plugin can ship work in any agent, not only Claude Code: MCP servers and skills.

use orion_core::plugins::{Catalog, PluginStore};

let catalog = Catalog::fetch("agenthub", "https://agenthub.nullorder.org/plugins.json").await?;
let entry = catalog.get("superpowers-chrome").expect("listed");

let store = PluginStore::new(PluginStore::default_root().expect("home directory"));
let prepared = store.prepare(&catalog.name, entry)?; // blocking
for (name, server) in &prepared.contents.mcp_servers {
    println!("MCP server {name}: {:?} {:?}", server.command, server.args);
}
let installed = store.commit(prepared)?;

Catalogs

Catalog::parse takes a marketplace.json object or a bare array of entries, and Catalog::fetch downloads one. Entries keep every field the format defines, and every source shape: github, url and git-subdir (each with an optional ref or sha), npm, and a path inside the marketplace. An entry that does not parse is skipped, so one bad entry does not hide the rest.

Catalog::search matches every word of a query against names, descriptions, tags, categories and authors. PluginEntry::components reads the component types from the tags, and is_portable says whether a plugin ships anything an agent outside Claude Code can use.

The store

PluginStore installs plugins into one directory, ~/.agents/plugins by default, which any tool can read:

installed.json               every installed plugin, with its pinned commit
<marketplace>/<plugin>/      its git checkout
catalogs/<marketplace>.json  the last fetched catalog

Installs take two steps. prepare fetches the plugin into a staging area (a shallow checkout, sparse for a plugin in a subfolder) at the entry’s sha, or the tip of its ref or default branch, and reads what it ships. Nothing from the plugin runs, git never asks for credentials, and only https:// (and file://) repositories are fetched. Show the user what the plugin’s MCP servers run, then commit to move it into place, or cancel.

latest_commit reports the commit an install would fetch now; compare it with InstalledPlugin::commit to offer updates. remove uninstalls. Store operations block, so run them under spawn_blocking in async code.

Contents

PluginContents::read reads a plugin folder:

• MCP servers from plugin.json mcpServers (inline, or a path to a file), else a root .mcp.json, plus any the catalog entry declares. Files may wrap the map in mcpServers or not. ${CLAUDE_PLUGIN_ROOT} is filled in and passed to stdio servers as an environment variable, as Claude Code does.
• Skills through discover_skills.
• Claude Code-only parts (commands, agents, hooks, language servers), so you can say what is left out.

required_programs lists what the stdio servers run (npx, node, uvx, …) so you can check they are installed first.