Support installable Agent Plugins

[sentry-junior]

Intent

Adopt Agent Plugins 1.0 as a portable plugin format that Junior can install and use without a deploy. This complements Junior's native plugin format; it does not replace native hooks, routes, tasks, credentials, migrations, runtime dependencies, or provider behavior.

Broad plan

• Add local schema validation for plugin.json, skills, and mcp.json, including the specification's path-containment and component-level failure rules.
• Add durable install, list, update, and remove operations for workspace-scoped Agent Plugins.
• Store source and version metadata so installed packages survive deploys and can be reproduced.
• Feed installed skills into Junior's normal skill discovery and matching.
• Feed supported MCP servers into Junior's normal deferred tool discovery.
• Keep native-only capabilities in Junior's native plugin format.
• Show installed Agent Plugins with integrations, not user-created tasks.

Delivery slices

1. Install and use skill-only Agent Plugins.
2. Add remote streamable HTTP MCP servers through Junior's current MCP runtime.
3. Add stdio MCP servers through the sandbox runtime.
4. Add update UX and optional update checks.

“Automatically use” means skills and MCP tools join Junior's existing discovery paths. It does not mean all plugin instructions and tools enter every prompt.

Requested by David Cramer.

--

View Junior Session [Sentry]