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+# Plugin Systems Comparison: Ours vs Claude vs emes
+
+> **Date:** 2026-01-09
+> **Status:** Living document
+> **Related:** [ADR-005](../adr/005-dual-publish-plugin-architecture.md)
+
+## Overview
+
+Three plugin/skill systems for AI coding agents:
+
+| System | Origin | Focus |
+|--------|--------|-------|
+| **Ours** | This repo | Cross-agent portability |
+| **Claude Plugins** | Anthropic (Oct 2025) | Claude Code extensibility |
+| **emes** | [evil-mind-evil-sword](https://github.com/evil-mind-evil-sword) | Mechanical quality enforcement |
+
+## Feature Comparison
+
+| Aspect | **Our System** | **Claude Plugins** | **emes** |
+|--------|---------------|-------------------|----------|
+| Primary file | `SKILL.md` | `plugin.json` + `skills/*.md` | `plugin.json` + tools |
+| Distribution | Nix + `deploy-skill.sh` | `/plugin install` + marketplace | `/plugin install @emes` |
+| Discovery | Symlink to `~/.claude/skills/` | Auto-discovery from `skills/` | Auto-discovery |
+| Multi-agent | ✅ Gemini, OpenCode, Claude | ❌ Claude only | ❌ Claude only |
+| Hooks | ❌ None | ✅ 9 lifecycle events | ✅ Uses hooks heavily |
+| Issue tracking | beads | N/A | tissue (their own) |
+| Quality gates | ❌ Manual | ✅ Hooks possible | ✅ idle (blocks exit) |
+| Messaging | N/A | N/A | jwz (async, identity-aware) |
+
+## Architectural Principles
+
+| Principle | Ours | Claude | emes |
+|-----------|------|--------|------|
+| Context injection | Push (SKILL.md loaded upfront) | Push (skill loaded upfront) | **Pull on-demand** |
+| Enforcement | Prompt-based ("please do X") | Hooks available but optional | **Mechanical (hooks required)** |
+| Content style | Inline markdown | Inline markdown | **References to files** |
+| Interface | Human-readable | Human-readable | **Machine-first (JSON)** |
+
+## Unique Strengths
+
+### What We Have (that others don't)
+
+1. **Cross-agent support** - Works with Gemini, OpenCode, not just Claude
+2. **Nix deployment** - Declarative, reproducible, system-level
+3. **Lenses pattern** - Multi-pass focused review (bloat, security, coupling, etc.)
+4. **beads integration** - Issue tracking across sessions
+
+### What Claude Has (that others don't)
+
+1. **Official support** - Anthropic-maintained, documented
+2. **Marketplace ecosystem** - Community plugins, discovery
+3. **Scope control** - user/project/local installation
+4. **9 lifecycle hooks** - SessionStart, PostToolUse, PreCompact, etc.
+
+### What emes Has (that others don't)
+
+1. **idle** - Quality gate that mechanically blocks exit until reviewer approves
+2. **tissue** - Issue tracker designed for agents (JSON, non-interactive)
+3. **jwz** - Async messaging with git context and identity
+4. **alice** - Adversarial reviewer agent (Opus-based)
+5. **Mechanical enforcement** - Hooks enforce policy, not prompts
+
+## emes Tool Details
+
+| Tool | Purpose | Language |
+|------|---------|----------|
+| **idle** | Quality gate - blocks exit until alice reviews | Shell + hooks |
+| **tissue** | Git-native issue tracking, machine-first | Zig |
+| **jwz** | Async messaging with identity/git context | Zig |
+| **marketplace** | Plugin distribution registry | JSON |
+| **alice** | Read-only Opus reviewer, creates issues | Agent |
+
+### emes Key Principles
+
+From their architecture:
+
+1. **Pull context on-demand** - Don't inject large prompts upfront
+2. **Mechanical enforcement** - Use hooks to enforce, not prompt instructions
+3. **References over inline** - Point to files, don't embed content
+4. **Machine-first interfaces** - JSON output, non-interactive CLIs
+
+## Philosophical Stances
+
+| System | Core Belief |
+|--------|-------------|
+| **Ours** | "Skills should work everywhere" - agent-agnostic |
+| **Claude** | "Plugins extend Claude Code" - platform-specific |
+| **emes** | "Enforce quality mechanically" - trust hooks, not prompts |
+
+## Integration Points
+
+### We Could Adopt from emes
+
+- [ ] **idle pattern** - Quality gate for code-review skill (skills-9jk)
+- [ ] **tissue** - Alternative to beads? (probably not, beads is good)
+- [ ] **Pull on-demand** - Reduce upfront context injection
+- [ ] **Machine-first** - JSON output modes for scripts
+
+### We Could Adopt from Claude
+
+- [x] **plugin.json** - Already doing via dual-publish
+- [x] **marketplace.json** - Already created
+- [ ] **Hooks** - Add to skills that need lifecycle events
+- [ ] **Scope control** - Let users choose install scope
+
+## Current Strategy: Dual-Publish
+
+We maintain both systems:
+
+```
+skills/my-skill/
+├── .claude-plugin/
+│   └── plugin.json        # Claude plugin system
+├── skills/
+│   └── my-skill.md        # Claude auto-discovery
+├── SKILL.md               # Nix deployment (cross-agent)
+└── README.md
+```
+
+**Rationale:** Cross-agent support is important. Gemini can't use Claude plugins (skills-bo8).
+
+## Open Questions
+
+1. Should we adopt tissue or stick with beads?
+2. How much of emes philosophy (mechanical enforcement) should we adopt?
+3. Can we make lenses work as Claude plugin hooks?
+4. Should skills output JSON for machine consumption?
+
+## References
+
+- [Claude Code Plugin Docs](https://code.claude.com/docs/en/plugins)
+- [emes org](https://github.com/evil-mind-evil-sword)
+- [emes idle](https://github.com/evil-mind-evil-sword/idle)
+- [emes tissue](https://github.com/evil-mind-evil-sword/tissue)
+- [Anthropic marketplace](https://github.com/anthropics/claude-code/blob/main/.claude-plugin/marketplace.json)