Vercel Composition Patterns

React Composition Patterns

Composition patterns for building flexible, maintainable React components. Avoid boolean prop proliferation by using compound components, lifting state, and composing internals. These patterns make codebases easier for both humans and AI agents to work with as they scale.

Triggers

• composition
• layout
• grid
• flexbox
• responsive
• breakpoint
• container
• spacing
• alignment
• structure
• page layout
• component composition

When to Apply

Reference these guidelines when:

• Refactoring components with many boolean props
• Building reusable component libraries
• Designing flexible component APIs
• Reviewing component architecture
• Working with compound components or context providers

Rule Categories by Priority

Quick Reference

1. Component Architecture (HIGH)

• architecture-avoid-boolean-props - Don't add boolean props to customize behavior; use composition
• architecture-compound-components - Structure complex components with shared context

2. State Management (MEDIUM)

• state-decouple-implementation - Provider is the only place that knows how state is managed
• state-context-interface - Define generic interface with state, actions, meta for dependency injection
• state-lift-state - Move state into provider components for sibling access

3. Implementation Patterns (MEDIUM)

• patterns-explicit-variants - Create explicit variant components instead of boolean modes
• patterns-children-over-render-props - Use children for composition instead of renderX props

4. React 19 APIs (MEDIUM)

⚠️ React 19+ only. Skip this section if using React 18 or earlier.

• react19-no-forwardref - Don't use forwardRef; use use() instead of useContext()

How to Use

Read individual rule files for detailed explanations and code examples:

rules/architecture-avoid-boolean-props.md
rules/state-context-interface.md

Each rule file contains:

• Brief explanation of why it matters
• Incorrect code example with explanation
• Correct code example with explanation
• Additional context and references

Full Compiled Document

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

Verify

• The change was rendered in a browser/simulator and a screenshot or DOM snapshot was captured, not just code-reviewed
• Layout was checked at the breakpoints the composition-patterns guide calls out (mobile + desktop minimum); evidence of each is attached
• Color, typography, and spacing values used come from the project's design tokens / theme, not hard-coded ad-hoc values
• Keyboard navigation and focus order were exercised on every interactive element introduced
• Reduced-motion / dark-mode (when supported) variants were verified, not assumed to inherit
• No console errors or hydration warnings were emitted during the verification render