Design Bridge

Runtime companion. Lives between DESIGN.md and findings.md.

When you (Claude) should run this skill

You are running this skill when ANY of the following is true:

1. The active phase in task_plan.md mentions UI keywords (button, card, modal, layout, color, typography, spacing, dialog, navigation, form, input, page, screen, theme, brand, design, component, header, footer, sidebar, hero, cta).
2. The user just asked you to build, change, or review a UI element.
3. The PreToolUse hook fired before a Write or Edit against a file matching .tsx|.jsx|.vue|.svelte|.html|.css|*.scss.
4. The user explicitly ran /mddesign:inject.

What to do

Step 1: Detect DESIGN.md

• Glob for DESIGN.md at the project root (CWD).
• If absent, do nothing. Surface a one-line note ONLY if the user explicitly invoked the skill: "No DESIGN.md found at project root. Run /mddesign:harvest to generate one from your codebase."

Step 2: Detect the relevant token slice

• Read DESIGN.md once.
• Identify the token categories the current task touches. Heuristics:

- "button|cta|link" → components.button, colors.primary, colors.secondary, typography (button), rounded - "card|panel|tile" → components.card, colors.surface, rounded, spacing - "modal|dialog|overlay" → components.modal, colors.surface, rounded, elevation - "form|input|field" → components.input, colors.border, typography (body), rounded - "color|theme|palette" → all colors - "type|font|heading" → all typography - "layout|grid|spacing" → spacing scale, layout section - default → colors (primary, secondary), typography (heading, body)

Step 3: Find the existing "## Design Context" block in findings.md

• Read findings.md.
• Look for a section header ## Design Context (case-sensitive).
• If absent, you will append a fresh block.
• If present, you will replace the block contents.

Step 4: Build the new block

The block format:

## Design Context

> Auto-injected by MDDesign on <ISO timestamp>. Source: DESIGN.md.
> Phase trigger: <phase id or "manual">

### Tokens in scope
<bulleted list of token references with values, format `colors.primary = #3B82F6`>

### Component specs in scope
<for each touched component, copy its spec from DESIGN.md verbatim>

### Do's and Don'ts (relevant excerpt)
<copy the relevant Do/Don't lines from DESIGN.md if any>

> If you stray from these tokens, name the deviation explicitly in findings.md before writing code.

Step 5: Write the block back to findings.md

• Use Edit with the old block as oldstring and your new block as newstring.
• If no existing block, use Edit to append: oldstring is the file's last existing line, newstring is the same line followed by \n\n## Design Context\n....

What you must never do

• Never Write or Edit DESIGN.md. Reading only. Harvest is a different skill.
• Never Write or Edit task_plan.md. Read only.
• Never extract or invent tokens not present in DESIGN.md. If a token is missing, surface it under ### Open token questions in findings.md.
• Never run if DESIGN.md is absent and the user did not explicitly invoke this skill.

Example

task_plan.md Phase 3 says "Build the primary CTA button on the landing page." DESIGN.md declares colors.primary = #4F46E5, components.button.backgroundColor = {colors.primary}, rounded.md = 6px. After this skill runs, findings.md gains:

## Design Context

> Auto-injected by MDDesign on 2026-04-23T10:14:00Z. Source: DESIGN.md.
> Phase trigger: phase-3

### Tokens in scope
- `colors.primary = #4F46E5`
- `colors.text-on-primary = #FFFFFF`
- `rounded.md = 6px`
- `typography.button = { fontFamily: Inter, fontSize: 16px, fontWeight: 600 }`

### Component specs in scope
**Button** (from DESIGN.md):
- backgroundColor: `{colors.primary}`
- textColor: `{colors.text-on-primary}`
- typography: `{typography.button}`
- rounded: `{rounded.md}`
- hover.backgroundColor: `{colors.primary-700}`

### Do's and Don'ts (relevant excerpt)
- Always use the primary color for the main page CTA.
- Never set fontSize on buttons outside the declared typography.button token.

> If you stray from these tokens, name the deviation explicitly in findings.md before writing code.

The agent now sees these constraints on every subsequent prompt because findings.md is in the planning-with-files attention loop.