ADS3-Design-System/ARCHITECTURE.md

ARCHITECTURE.md — ADS 3.0 Design System

This is the living architecture document for the ADS 3.0 design system. All structural decisions are recorded here. Update this document when the architecture evolves — never let the codebase and this document drift apart.

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1. Overview

ADS 3.0 Design System is a React component library implementing the ADS 3.0 (Adaptive Design System) design language. It provides tokens, primitives, and composite components as a shared foundation. Application-specific screens and domain logic belong in downstream forks of this repo.

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2. Token Pipeline

Figma (design tool)
  ↓  Figma MCP / get_variable_defs
src/tokens/tokens.css (@theme block)
  ↓  Tailwind CSS v4 reads @theme
  ↓  Generates utility classes + CSS custom properties
Components (use Tailwind utilities or var() references)
  ↓  Rendered in
Storybook (visual verification)

Token Layers

Tokens are structured in three layers:

1. Palette — raw colour values (--color-blue-01, --color-grey-03). Not used directly in components.
2. Semantic — purpose-based aliases (--color-primary, --color-error, --color-text). General UI usage.
3. Form control — shared interactive-state tokens for all form components (--color-control-border, --color-control-checked, --color-control-label, etc.). Ensures consistent styling across Input, Checkbox, Radio, Switch, Select, and future form primitives.
4. Button — dedicated tokens for the Button component's intent system (--color-button-default, --color-button-danger, --color-button-neutral, --color-button-subtle-bg, --color-button-subtle-text).
5. Badge — status colour tokens for the Badge component's variant system (--color-badge-info, --color-badge-success, --color-badge-error, --color-badge-warning, --color-badge-neutral, --color-badge-text).
6. Chip — tokens for the Chip component's border/fill states (--color-chip-border, --color-chip-text, --color-chip-bg, --color-chip-selected-bg, --color-chip-selected-text).
7. Tag — colour tokens for the Tag component's 11-colour system (--color-tag-navy, --color-tag-blue, --color-tag-green, --color-tag-red, --color-tag-orange, --color-tag-grey, --color-tag-teal, --color-tag-brown, --color-tag-purple, --color-tag-fuchsia, --color-tag-yellow, plus -light variants for each).
8. Alert — background, border, and icon colour tokens for 5 alert variants (--color-alert-{variant}-bg, --color-alert-{variant}-border, --color-alert-{variant}-icon for info, warning, error, success, neutral).
9. Switch — dedicated on-state tokens (--color-switch-on, --color-switch-on-hover) using success green per ADS 3.0.
10. Avatar — background and text colour tokens (--color-avatar, --color-avatar-text).
11. TopBar — background colour token (--color-topbar).
12. SideNav — navigation-specific tokens (--color-nav-bg, --color-nav-text, --color-nav-icon, --color-nav-active, --color-nav-divider).

Token Categories

• Palette colours: --color-{palette}-{shade} — 10 families (blue, red, orange, green, teal, brown, purple, fuchsia, yellow, grey) × 4 shades each
• Semantic colours: --color-{purpose} (e.g., --color-primary = navy, --color-info = bright blue, --color-error, --color-text)
• Form control colours: --color-control-{role} (e.g., --color-control-border, --color-control-checked)
• Button colours: --color-button-{intent} (e.g., --color-button-default, --color-button-danger)
• Badge colours: --color-badge-{variant} (e.g., --color-badge-info, --color-badge-error)
• Chip colours: --color-chip-{role} (e.g., --color-chip-border, --color-chip-selected-bg)
• Tag colours: --color-tag-{color} and --color-tag-{color}-light (e.g., --color-tag-blue, --color-tag-blue-light)
• Radii: --radius-* (sm, default, lg, full)
• Shadows: --shadow-* (default, md)

How Tailwind v4 @theme Works

Declaring --color-primary: #2563eb inside @theme in tokens.css automatically generates utilities like bg-primary, text-primary, border-primary. No JavaScript config file needed — the CSS file is the config.

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3. Component Taxonomy

src/components/atoms/ — Atoms

Single-purpose, atomic building blocks. Each wraps a single native element or interaction pattern with no domain logic.

• Button, IconButton
• Input, Textarea, Select, Autocomplete
• Checkbox, Radio/RadioGroup, Switch
• Slider, RangeSlider
• FileInput
• Badge, Tag, Chip
• Tabs (TabList, Tab, TabPanel)
• List (ListItem, ListSubheader, ListDivider)
• Avatar, Tooltip

src/components/molecules/ — Molecules

Small compositions of atoms into reusable units. May combine icons, text, buttons, or other atoms.

• Alert, Accordion, Card, Dialog, Popover
• DataTable

src/components/organisms/ — Organisms

Larger compositions that carry domain semantics or define page-level regions. Built from atoms and molecules.

• TopBar, SideNav, PageHeader
• (planned) DatePicker

src/components/templates/ — Templates

Page-level layout components that define the shell and content structure. Templates accept typed slot props (ReactNode) for their sections, making them composable by AI agents and developers. They do not own content — they define where content goes.

• AppShell — TopBar + SideNav + scrollable content area. All pages render inside this.
• DashboardPage — PageHeader + stat cards row + responsive 2-column content grid
• ListPage — PageHeader + stat cards + list header with actions + scrollable item list
• FormPage — PageHeader + optional action bar + optional vertical stepper + constrained-width form content
• DetailPage — PageHeader + optional action bar (e.g. tabs) + single-column constrained content for viewing records/profiles/documents

Templates have Storybook stories tagged ['autodocs', 'template'] that show realistic "recipe" compositions — full pages built from real components with sample data. These serve as reference implementations for AI coding agents.

Which Tier Does a Component Belong To?

Question	If yes →
Does it wrap a single native element or a single interaction pattern (button, input, toggle)?	atoms/
Does it compose 2+ atoms into a reusable unit (e.g., Alert = icon + text + close button)?	molecules/
Does it carry domain-specific naming or logic (e.g., ThemeCard, ParticipantRow)?	organisms/
Does it define a page-level region or shell (header, sidebar, content area)?	organisms/
Does it define the layout structure of a full page (slot-based, no owned content)?	templates/

When in doubt: start in atoms/. Promote to molecules/ when a component begins importing other atoms.

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4. Styling Approach

• Primary: Tailwind utility classes
• Conditional classes: cn() from @/lib/utils (clsx + tailwind-merge)
• Token values: Always from src/tokens/tokens.css, never hardcoded
• Token discipline: Components reference semantic or domain-specific tokens (form-control, button), not palette tokens. If the needed token doesn't exist, add it to tokens.css before using a raw palette value.
• No CSS modules, no styled-components, no inline styles (except truly dynamic values)
• Class ordering: Enforced by prettier-plugin-tailwindcss

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5. Storybook Conventions

• Every component has a co-located .stories.tsx file
• All stories use tags: ['autodocs'] for auto-generated docs
• Stories cover: default state, all variants, edge cases, disabled/error states
• A11y addon runs on all stories — violations should be addressed
• MCP addon enabled at localhost:6006/mcp for AI-assisted development

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6. Project Structure

src/
├── components/
│   ├── atoms/            # Single-purpose elements
│   ├── molecules/        # Small compositions of atoms
│   ├── organisms/        # Domain-aware / page-level components
│   └── templates/        # Page-level layout components (slot-based)
├── tokens/
│   └── tokens.css        # Design tokens (@theme block)
├── styles/
│   └── global.css        # Tailwind imports + base styles
├── lib/
│   └── utils.ts          # cn() utility
├── hooks/                # Custom React hooks
├── App.tsx               # Root component
└── main.tsx              # Vite entry point

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7. Design Tool Integration

Figma

• Project file: https://www.figma.com/design/mrabO6AtxN3ektGiTk0I9c/ResearchInsights (file key: mrabO6AtxN3ektGiTk0I9c)
• MCP server: Official Figma Remote MCP at https://mcp.figma.com/mcp (HTTP transport, OAuth auth)
• Key tools: get_design_context, get_variable_defs, get_screenshot, search_design_system, use_figma
• Design tokens extracted via get_variable_defs → mapped to @theme values in tokens.css

Code Connect

• Links Figma components to their React implementations
• Once linked, get_design_context returns actual component code instead of generic markup
• Mapped as we build each component via add_code_connect_map (label: "React")

Storybook MCP

• Available at localhost:6006/mcp when Storybook dev server is running
• Provides: component listing, documentation retrieval, story generation, a11y testing
• @storybook/addon-designs embeds Figma frames in the story panel for side-by-side comparison
• @storybook/addon-mcp serves the MCP endpoint

claude2figma Skills

• 4 skills in .claude/skills/ that enforce design system compliance when writing to Figma
• figma-preflight: Validates MCP connection, audits libraries, builds a Token Map of all styles/variables
• component-rules: Library-first lookup, Auto Layout conventions, semantic node naming
• figma-style-binding: All visual values must bind to Figma Styles or Variables, never hardcoded; includes post-write QA
• reference-interpreter: Converts screenshots/references into structured Design Briefs mapped to design tokens