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name: component-building description: Component building guidelines for creating high-quality, accessible, and composable registry components. Triggers on tasks involving building a component, adding or building a block, new block, registry component. Use when working in src/registry/. license: MIT metadata: author: shadcraft version: "1.0.0"

Component Building Guidelines

Comprehensive component authoring guide for building registry components that follow shadcn/ui patterns, emphasizing composition, accessibility, type safety, and maintainability.

When to Apply

Reference these guidelines when:

• Creating new components in src/registry/
• Building blocks that compose shadcn/ui primitives
• Reviewing component code for patterns and best practices
• Refactoring existing registry components

Rule Categories

Quick Reference

Core Principles

1. Default to shadcn/ui + Radix primitives - Don't rebuild what exists
2. Composition over configuration - Split into focused parts (Root, Trigger, Content)
3. Semantic HTML first - Use appropriate elements, add ARIA only when needed
4. Single element wrapping - Each component wraps one element for composability
5. Extend native attributes - Use React.ComponentProps<'element'> patterns
6. Data attributes for state - Use data-state, data-slot instead of prop explosion
7. Semantic tokens - Never hardcode colors; use design tokens

Naming Conventions

Follow established patterns from shadcn/ui and Radix UI:

• Root, Trigger, Content - For interactive compositions
• Header, Body, Footer - For structural layouts
• Title, Description - For text content areas

Key Patterns

• Controlled + Uncontrolled: Support both via useControllableState
• asChild + Slot: Merge props onto child elements without wrapper DOM
• CVA: Use Class Variance Authority for variant-heavy components
• cn(): Merge classes with Tailwind conflict resolution

How to Use

Read individual rule files for detailed explanations and examples:

Copyrules/composition.md
rules/accessibility.md
rules/typescript-patterns.md

Each rule file contains:

• DO patterns with references to components.build guides
• DON'T anti-patterns to avoid
• Links to source documentation

Full Compiled Document

For the complete guide with all rules expanded: AGENTS.md