Cross-engine support: Agency plugin (MCP + hooks) → public Claude Code plugin

Summary

Expand brag-sheet from Copilot CLI-only to work across both Copilot CLI and Claude Code, using Agency as the internal distribution layer and MCP as the universal tool protocol.

Product Strategy

Phase 1: Agency Plugin (internal Microsoft)

• Goal: All MSFT employees using Agency can auto-track work
• Distribution: XPASS marketplace (skill-only PR already open)
• Build: MCP server wrapping lib/ modules (3 tools) + hooks.json for session lifecycle
• Key insight: Agency abstracts the engine — one plugin works with both agency copilot and agency claude

Phase 2: Public Claude Code Plugin

• Goal: External visibility, works for any Claude Code user
• Distribution: Claude Code plugin marketplace, npm

Architecture

• lib/ (shared core, zero deps) — already done
• mcp-server.mjs (NEW) — MCP stdio server exposing 3 tools
• hooks.json (NEW) — session start/end lifecycle
• .claude-plugin/plugin.json (NEW) — plugin manifest
• extension.mjs — continues working for standalone Copilot CLI

What needs building

1. MCP server (~100-150 lines)
2. hooks.json for session lifecycle
3. Plugin manifest (.claude-plugin/plugin.json)

References

• Agency plugin docs: 1esgitops/_git/agency
• awesome-copilot skill: merged (PR #1428)
• Copilot CLI bug #3023

Start by reading the shared modules in lib/ and the existing extension.mjs entry point. Add mcp-server.mjs, hooks.json, and .claude-plugin/plugin.json as described, exposing the three tools and session lifecycle. Done means the Agency plugin supports both Copilot and Claude Code while standalone Copilot CLI continues to work.