MDDesign

Glue layer for AI coding agents. Composes planning-with-files, Google's DESIGN.md, memory routing, agent teams, and session handoff into one orchestrator. Cross-IDE. No replacements.

---

What it does

You already use planning-with-files. You already use DESIGN.md (or want to). You already manage memory and agent dispatch by hand. MDDesign is the missing layer that wires them together so your agent sees the right design tokens at the right moment, dispatches the right subagent for the right phase, and never loses context after /clear.

It does not replace any underlying tool. It composes them.

Commands

Command	What it does
/mddesign:setup	Detect missing dependencies, print exact install steps for your platform
/mddesign:doctor	Six-probe diagnostic. Use when something is broken
/mddesign:compose	One-shot wiring check at the start of a project
/mddesign:harvest	Scan your codebase, write a structurally valid DESIGN.md at project root
/mddesign:critique	Five-pass audit: structural / drift / a11y / completeness / consistency
/mddesign:fix <id>	Apply one finding from the critique. HITL gated. Re-lints after every edit.
/mddesign:inject	Manually inject DESIGN.md tokens into the active phase's findings.md
/mddesign:handoff	Force a session catchup or memory promotion. Survives /clear.
/mddesign:memory	Three-tier memory: scratch / WHERE (QMD) / WHY (MemPalace)
/mddesign:team	Dispatch a phase to a specialist subagent via PhaseSpec v1

What you get over raw planning-with-files

• Design tokens follow you. Every UI prompt sees the relevant slice of DESIGN.md injected into findings.md. No more agents inventing hex codes.
• Code-to-DESIGN.md harvest. Most repos do not have a DESIGN.md. /mddesign:harvest scans your existing code and writes one. The on-ramp for every existing project, not just greenfield.
• Sessions survive /clear. Stop hook stamps a handoff. SessionStart hook reads the last stamp + the most recent decisions from MemPalace and rebuilds context in one paragraph.
• Decisions persist forever. Three-tier memory: scratch (file-tier, fast), WHERE (QMD, locational), WHY (MemPalace, decisions). Promotions to WHY are HITL gated.
• Specialist subagents on demand. Hand a phase to a design-archeologist for harvest, a memory-keeper for classification, an executor for the rest. PhaseSpec v1 is the only handoff format.

Quickstart

1. Install

# Add the marketplace
/plugin marketplace add OthmanAdi/MDDesign

# Install the plugin
/plugin install mddesign@mddesign

2. Verify dependencies

/mddesign:setup

This walks you through every missing dependency with exact install steps. Safe to run multiple times.

Required:

• Node + npx (for @google/design.md lint)
• planning-with-files skill

Optional but recommended:

• code-memory-router skill (powers WHY/WHERE tiers)
• MemPalace MCP (powers WHY tier persistence)
• QMD MCP (powers WHERE tier search)

3. Use it

# In any project
/mddesign:compose          # check the wiring
/mddesign:harvest          # generate DESIGN.md from your existing code
/mddesign:critique         # audit it for drift, a11y, completeness

That is the whole inner loop.

How the pieces fit

your existing code
   │
   ▼
/mddesign:harvest ──► DESIGN.md  (Google Labs spec, lint-validated)
                        │
                        ▼
                   /mddesign:critique  ──► DESIGN.md.critique.md
                        │
                        ▼
on every UI phase, design-bridge auto-injects the relevant token slice
into findings.md "## Design Context" — your agent reads it on every turn

                        │
                        ▼
       /mddesign:team dispatch  ──► specialist subagent (PhaseSpec v1)
                        │
                        ▼
       /mddesign:memory   scratch  ◄── session ends, Stop hook fires
                          WHERE   ◄── QMD via code-memory-router
                          WHY     ◄── MemPalace, HITL gated

                        │
                        ▼
         /mddesign:handoff  ── SessionStart catchup pulls last
                              decisions back into context

Full architecture: docs/architecture.md.

Core preservation rules

These are load-bearing. MDDesign exists because it does not violate them.

1. planning-with-files core untouched. Never write to task_plan.md.
2. DESIGN.md only written under explicit user action (/mddesign:harvest or /mddesign:fix).
3. Memory is a layer on top of code-memory-router, never a replacement.
4. Subagents share state via markdown on disk. No in-memory shared store.
5. Structural DESIGN.md validation delegated to npx @google/design.md lint. Never reimplement Google's linter.

IDE support

IDE	Sync dir	Skills	Agents	Commands	Hooks
Claude Code	(canonical)	yes	yes	yes	yes
Cursor	.cursor/	yes	yes	yes	manual
Codex CLI	.codex/	yes	yes	yes	manual
Windsurf	.windsurf/	yes	yes	yes	manual
Cline	.clinerules/	yes	no	no	n/a
OpenCode	.opencode/	yes	yes	yes	manual

Mirrors regenerated by python scripts/sync-ide-folders.py before each release.

Example

A walkthrough is in examples/basic-react-app/ showing what task_plan.md, findings.md (with the auto-injected ## Design Context block), and a harvested DESIGN.md actually look like for a small React project.

Project layout

MDDesign/
├── README.md
├── LICENSE                          Apache-2.0
├── CONTRIBUTING.md
├── CHANGELOG.md
├── .claude-plugin/
│   ├── plugin.json
│   └── marketplace.json
├── hooks/
│   ├── hooks.json
│   ├── session-start/
│   ├── prompt-submit/
│   ├── pre-tool-use/
│   └── stop/
├── skills/
│   ├── design-bridge/SKILL.md       runtime: DESIGN.md → findings.md
│   ├── design-harvest/SKILL.md      harvest + critique + fix
│   ├── memory-layer/SKILL.md        three-tier memory
│   ├── session-handoff/SKILL.md     catchup + promote
│   └── team-dispatch/SKILL.md       PhaseSpec v1 dispatch
├── commands/                        slash commands (10)
├── agents/                          subagent definitions
├── docs/architecture.md
├── examples/basic-react-app/        walkthrough
├── tests/                           smoke tests (bash + PowerShell)
└── scripts/sync-ide-folders.py

Contributing

See CONTRIBUTING.md. Short version: feature-branch PRs, no Co-Authored-By, smoke tests must pass on both bash and PowerShell.

License

Apache-2.0. Same as Google Labs DESIGN.md and planning-with-files.