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design-brief

nexu-io/open-design

Parse design briefs into concrete specs using structured I-Lang protocol format.

What is design-brief?

Converts vague design requests into explicit, unambiguous specifications across 8 dimensions: palette, typography, layout, mood, density, and constraints. Use this when you need to eliminate ambiguity from natural language design briefs and generate a concrete DESIGN.md file.

  • Accepts design briefs in I-Lang structured format or natural language and converts them to explicit specifications
  • Maps natural language phrases (e.g., 'clean minimal dark mode') to closed-vocabulary design dimensions
  • Resolves 8 orthogonal design dimensions: color palette, accent color, body typography, display typography, layout model, mood, density, and constraints
  • Generates DESIGN.md with concrete design tokens (colors, fonts, spacing, sizing rules)
  • Produces optional HTML preview of the design brief
  • Validates all dimensions against closed vocabulary and prompts for clarification on unrecognized values

How to install design-brief

npx skills add https://github.com/nexu-io/open-design --skill design-brief
Claude Code
Cursor
Windsurf
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How to use design-brief

  1. 1.Provide a design brief in either I-Lang structured format or natural language (e.g., 'dark mode, minimal, Inter font, spacious layout')
  2. 2.The skill maps natural language phrases to the 8 design dimensions using the provided mapping table
  3. 3.Review the resolved dimensions; if any are unspecified, sensible defaults are applied
  4. 4.The skill generates DESIGN.md with concrete design tokens (hex colors, font families, spacing values, sizing rules)
  5. 5.Optionally view the brief-preview.html to see a visual representation of the design decisions
  6. 6.Use the generated DESIGN.md as input to downstream design or layout skills

Use cases

Good for
  • Creating a landing page brief: convert 'I need a clean, minimal dark-mode SaaS landing page with Inter font' into structured specs
  • Standardizing design requests across a team by enforcing explicit dimension choices instead of vague terms like 'professional'
  • Generating design system documentation (DESIGN.md) that downstream skills can consume for consistent implementation
  • Disambiguating design feedback by mapping subjective phrases ('spacious', 'playful', 'brutalist') to concrete token values
  • Onboarding new designers by showing how natural language translates to the 8-dimension framework
Who it's for
  • Product designers and design leads creating briefs for developers or design systems
  • Agents and coding assistants that need to generate design specifications from user requests
  • Teams standardizing design language across multiple projects
  • Design system maintainers documenting design decisions in machine-readable format

design-brief FAQ

What if I provide a design value that isn't in the closed vocabulary?

The skill will prompt you for clarification and list the valid options for that dimension. For example, if you say 'ocean blue palette', it will ask if you meant navy_and_white, monochrome_dark, light_clean, or earth_tones.

Can I mix I-Lang structured format with natural language?

Yes. The skill accepts either pure I-Lang format, pure natural language, or a hybrid. It will parse and normalize all input to the 8-dimension framework.

What happens if I don't specify all 8 dimensions?

The skill applies sensible defaults for any missing dimensions. You can review these defaults in the generated DESIGN.md and adjust if needed.

What is I-Lang protocol format?

I-Lang is a structured notation for design briefs using key=value pairs (e.g., palette=navy_and_white, mood=professional_minimal). It eliminates ambiguity by forcing explicit choices from a closed vocabulary.

Can I use this skill to generate design tokens for a custom design system?

Yes. The skill resolves symbolic values (e.g., palette=navy_and_white) to concrete design tokens (hex colors, font families, spacing values) that you can use in your design system or CSS.

Full instructions (SKILL.md)

Source of truth, from nexu-io/open-design.


name: design-brief description: | Parse a structured design brief written in I-Lang protocol format into a concrete design spec. Eliminates ambiguity from vague requests like "make it professional" by requiring explicit dimensions: palette, typography, layout, mood, density, and constraints. Trigger keywords: "design brief", "create a design brief", "ilang brief", "structured brief". triggers:

  • "design brief"
  • "create a design brief"
  • "ilang brief"
  • "structured brief" od: mode: design-system platform: desktop scenario: planning preview: type: html entry: brief-preview.html reload: debounce-100 design_system: requires: false generates: true sections: [visual-theme, color-palette, typography, component-stylings, layout, depth-elevation, dos-and-donts, responsive, agent-prompt-guide] inputs:
    • name: brief type: string required: true description: "I-Lang formatted design brief or natural language description" outputs: primary: DESIGN.md secondary: brief-preview.html capabilities_required:
    • file_write

Design Brief Skill

Parse a structured design brief into a concrete DESIGN.md and optional visual preview. Agent, follow this workflow exactly.

Background

The 8 dimensions in this skill were derived from OpenDesign's original 71-system catalog; 71 is the research sample, not the current bundled-system count. Every DESIGN.md in design-systems/ still resolves at minimum: color palette, accent, typography, display font, layout model, and component style. We distilled these into 8 orthogonal dimensions that cover the decisions a designer makes before any pixel is placed. Mood and density were added because they are the two most common sources of ambiguity in natural language briefs ("make it clean" means different things to different people).

Dimensions intentionally excluded from the brief level: animation timing, responsive strategy, and accessibility contrast. These are enforced at the template level by individual skills (e.g., saas-landing handles its own responsive logic), though the generated DESIGN.md includes sensible breakpoint defaults for downstream consumption.

1. Accept input

The user provides a design brief in one of two formats:

Option A: I-Lang structured brief

[PLAN:@DESIGN|type=saas_landing]
  |palette=navy_and_white|accent=coral
  |typography=inter|display=space_grotesk
  |layout=single_column|max_width=1200px
  |mood=professional_minimal
  |density=spacious|section_gap=96px
  |hero=headline+subhead+cta
  |sections=features,pricing,testimonials,footer
  |exclude=animations,parallax,gradients
  |responsive=mobile_first

Option B: Natural language

"I need a landing page for a developer tool. Clean, minimal, dark mode. Inter font. No flashy animations."

If the user provides Option B, convert it to the structured format using the mapping table below, then proceed. Identify every dimension explicitly stated and flag dimensions that were left unspecified.

Natural language → I-Lang mapping

For each sentence in the natural language input, identify dimension keywords and map to the closest structured value:

Natural language phraseDimensionI-Lang value
"dark mode", "dark theme"palettemonochrome_dark
"light", "white background"palettelight_clean
"earthy", "warm tones"paletteearth_tones
"pop of color", "vibrant"accentelectric_blue (default) or coral
"subtle accent"accentmuted_sage (default) or slate
"clean", "minimal", "simple"moodprofessional_minimal
"playful", "fun", "friendly"moodplayful
"bold", "brutalist", "raw"moodbrutalist
"editorial", "magazine-like"moodeditorial
"spacious", "lots of whitespace"densityspacious
"compact", "dense", "information-rich"densitycompact
"Inter", "system font"typographyinter (default) or system_ui
"serif", "traditional"typographygeorgia (default) or playfair
"monospace", "code-like"typographyjetbrains_mono
"no animations", "static"excludeanimations
"no gradients"excludegradients
"no stock photos"excludestock_photos
"single page"layoutsingle_column
"two columns", "sidebar"layouttwo_column
"mobile first"responsivemobile_first

When a phrase maps to multiple dimensions (e.g. "clean dark landing page" → mood=professional_minimal + palette=monochrome_dark + layout=single_column), resolve each dimension independently. When multiple values are listed for a single mapping, the first is the default; the agent may select the alternative only if surrounding context strongly favors it.

2. Validate dimensions

Every design brief must resolve these 8 dimensions. If any are missing from the input, select sensible defaults using the rules in Section 2.2.

The values listed below form a closed vocabulary. Only values in this table have concrete token mappings in Section 2.1. If the user provides a value not listed here, the agent must prompt for clarification rather than guessing.

#DimensionKeyExample values
1Color palettepalettenavy_and_white, earth_tones, monochrome_dark, light_clean
2Accent coloraccentcoral, electric_blue, emerald, muted_sage
3Body typographytypographyinter, system_ui, dm_sans, georgia
4Display typographydisplayspace_grotesk, clash_display, same_as_body, playfair
5Layout modellayoutsingle_column, two_column, asymmetric
6Moodmoodprofessional_minimal, playful, brutalist, editorial
7Densitydensitycompact, balanced, spacious
8Constraintsexcludeanimations, gradients, stock_photos, carousel

2.1 Symbolic → concrete token resolution

Each symbolic value maps to concrete design tokens. The agent must resolve these before writing DESIGN.md:

Symbolic valueConcrete tokens
palette=navy_and_whiteBackground: #0F172A, Surface: #1E293B, Text: #F8FAFC, Secondary: #94A3B8
palette=monochrome_darkBackground: #09090B, Surface: #18181B, Text: #FAFAFA, Secondary: #A1A1AA
palette=light_cleanBackground: #FFFFFF, Surface: #F8FAFC, Text: #0F172A, Secondary: #64748B
palette=earth_tonesBackground: #FFFBEB, Surface: #FEF3C7, Text: #451A03, Secondary: #92400E
accent=coralAccent: #F97316, Hover: #EA580C
accent=electric_blueAccent: #3B82F6, Hover: #2563EB
accent=emeraldAccent: #10B981, Hover: #059669
accent=muted_sageAccent: #84A98C, Hover: #6B8F73
accent=slateAccent: #64748B, Hover: #475569
typography=interBody: Inter, 400, 1rem/1.6
typography=system_uiBody: system-ui, 400, 1rem/1.6
typography=dm_sansBody: DM Sans, 400, 1rem/1.6
typography=georgiaBody: Georgia, 400, 1.125rem/1.7
display=space_groteskDisplay: Space Grotesk, 700, clamp(2rem, 5vw, 3.5rem)
display=clash_displayDisplay: Clash Display, 700, clamp(2rem, 5vw, 3.5rem)
display=playfairDisplay: Playfair Display, 700, clamp(2rem, 5vw, 3.5rem)
display=same_as_bodyDisplay inherits body font family, weight 600
density=compactSection spacing: 48px, Content padding: 16px/24px
density=balancedSection spacing: 72px, Content padding: 24px/40px
density=spaciousSection spacing: 96px, Content padding: 24px/48px

Symbolic values not in this table are not valid. If the user provides an unrecognized value (e.g., palette=ocean_blue), the agent must prompt for clarification: "I don't recognize palette=ocean_blue. Did you mean navy_and_white, monochrome_dark, light_clean, or earth_tones?"

2.2 Default resolution rules

When a dimension is unspecified, defaults are selected based on mood compatibility:

Unspecified dimensionDefault rule
paletteIf mood=editorial → light_clean. If mood=brutalist → monochrome_dark. Otherwise → light_clean.
accentIf palette is dark → coral. If palette is light → electric_blue.
typographyAlways → inter (highest cross-platform legibility).
displayIf mood=editorial → playfair. If mood=brutalist → space_grotesk. Otherwise → same_as_body.
layoutAlways → single_column (safest responsive default).
moodAlways → professional_minimal (least opinionated).
densityAlways → balanced.
excludeAlways → none (no constraints unless specified).

If mood is also unspecified, all defaults fall back to the safe neutral set: palette=light_clean, accent=electric_blue, typography=inter, display=same_as_body, layout=single_column, mood=professional_minimal, density=balanced, exclude=none.

3. Generate DESIGN.md

This skill generates a new DESIGN.md from scratch based on the resolved brief dimensions. If a DESIGN.md already exists in the working directory, the agent should ask the user whether to overwrite or skip.

Produce a DESIGN.md using the nine-section outline below. This outline is the skill's portable standalone output, inherited from OpenDesign's original upstream baseline; it is not the current repository package schema. Current bundled packages also carry manifest.json, tokens.css, and optional rich resources, while legacy and user-installed DESIGN.md-only content remains readable. All color hex values, font stacks, and spacing values must come from the resolved tokens in Section 2.1 — do not invent values outside the resolution table.

# [Project Name] Design System

## Visual Theme & Atmosphere
- Mood: [resolved from mood]
- Feel: [derived from mood — e.g., professional_minimal → "Clean, confident, restrained"]
- References: [if mood=editorial → "Magazine layouts, Monocle, Cereal"; if mood=brutalist → "Exposed structure, raw typography"]

## Color Palette & Roles
- Background: [resolved from palette]
- Surface: [resolved from palette]
- Text primary: [resolved from palette]
- Text secondary: [resolved from palette]
- Accent: [resolved from accent]
- Accent hover: [resolved from accent]

## Typography Rules
- Display: [resolved from display], 700, clamp(2rem, 5vw, 3.5rem)
- Body: [resolved from typography], 400, 1rem/1.6
- Mono: JetBrains Mono, 400, 0.875rem

## Component Stylings
- Buttons: [if mood=playful → "rounded-full", otherwise → "rounded-md"], accent bg, contrast text
- Cards: surface bg, subtle border, 12px radius
- Inputs: [if mood=brutalist → "thick border", otherwise → "transparent bg, bottom border"]

## Layout Principles
- Max width: 1200px
- Grid: [resolved from layout]
- Section spacing: [resolved from density]
- Content padding: [resolved from density]

## Depth & Elevation
- Shadows: [if mood=brutalist → "hard 4px offset", if mood=professional_minimal → "none", otherwise → "subtle sm"]
- Borders: 1px solid [derived from palette, 8% opacity of text color]

## Do's and Don'ts
- DO use the declared color tokens exclusively.
- DO maintain consistent section spacing.
- DO ensure all text meets WCAG AA contrast ratio.
- DON'T invent colors outside the palette.
- DON'T add decorative shadows unless Depth & Elevation allows them.
- DON'T use more than 2 display/body typefaces (monospace is a utility face for code and data — it does not count toward this limit).

## Responsive Behavior
- Breakpoints: 640px (sm), 768px (md), 1024px (lg), 1280px (xl)
- Mobile: single column, stack all sections vertically
- Tablet: allow 2-column feature grids
- Desktop: full layout with max-width constraint
- Images: fluid, max-width 100%, maintain aspect ratio

## Agent Prompt Guide
- Do NOT invent colors outside this palette.
- Do NOT add box-shadows unless specified above.
- Accent color appears maximum 3 times per viewport.
- All interactive elements need :focus-visible outline.
- [if exclude contains items → list each as "Do NOT use {item}."]

4. Generate brief-preview.html

Create a single HTML file that visually renders the resolved design tokens. The preview must contain these 4 sections in order:

  1. Color palette swatches — A horizontal row of rectangles, each showing one color from the Color section. Label each with its role (Background, Surface, Text, Accent) and hex code.
  2. Typography specimens — Three text blocks showing Display, Body, and Mono fonts at their declared sizes. Use a sample sentence ("The quick brown fox...") for each.
  3. Spacing ruler — A visual ruler or stacked bars showing section spacing and content padding values, labeled with their px values.
  4. Component preview — Render 2–3 live components (a primary button, a card with title/body, a text input) using the resolved tokens. These should be functional HTML/CSS, not screenshots.

Style the preview itself with the resolved design system tokens (background color, font, spacing). The preview should look like a design system documentation page.

5. Report unspecified dimensions

At the end of output, list any dimensions the user did not specify and the defaults that were applied, including the rule that selected each default:

Dimensions resolved from defaults:
- display: set to "same_as_body" (rule: mood=professional_minimal → same_as_body)
- density: set to "balanced" (rule: static fallback, no spacing preference given)
- exclude: set to "none" (rule: no constraints unless specified)

This transparency prevents silent assumptions from propagating into the final design.