Composition Patterns

---
name: vercel-composition-patterns
description: "Use this skill when working with `composition-patterns` tasks in the `engineering_agentops` domain."
  React composition patterns that scale. Use when refactoring components with
  boolean prop proliferation, building flexible component libraries, or
  designing reusable APIs. Triggers on tasks involving compound components,
  render props, context providers, or component architecture. Includes React 19
  API changes.
license: MIT
metadata:
  author: vercel
  version: '1.0.0'
skill_id: engineering_agentops.composition_patterns
executor: LLM_BEHAVIOR
status: ADOPTED
security: { level: standard, pii: false, approval_required: false }
anchors:
  - engineering
  - agent
  - orchestration
tier: 1
input_schema:
  - name: code_or_task
    type: string
    description: "Code snippet, script, or task description to process"
    required: true
  - name: context
    type: string
    description: "Additional context or background information"
    required: false
output_schema:
  - name: result
    type: string
    description: "Generated or refactored code output"
  - name: explanation
    type: string
    description: "Explanation of changes or implementation decisions"
what_if_fails: >
  FALLBACK: If Vercel Composition Patterns cannot complete, provide partial results with
  explicit gaps noted. Never block workflow silently.
  ESCALATE: If core capability is unavailable, suggest nearest alternative skill.
  RULE: Always explain what failed and what manual steps can substitute.
---

# 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.

## 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

| Priority | Category                | Impact | Prefix          |
| -------- | ----------------------- | ------ | --------------- |
| 1        | Component Architecture  | HIGH   | `architecture-` |
| 2        | State Management        | MEDIUM | `state-`        |
| 3        | Implementation Patterns | MEDIUM | `patterns-`     |
| 4        | React 19 APIs           | MEDIUM | `react19-`      |

## 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`

## Why This Skill Exists
<!-- TODO: describe why this skill was created and what problem it solves -->
Provides specialized `composition-patterns` capability to the APEX system.

## When to Use
<!-- TODO: describe when to invoke this skill vs alternatives -->
Use this skill when working with `composition-patterns` tasks in the `engineering_agentops` domain.

## What If Fails
<!-- TODO: describe fallback behavior -->
FALLBACK: Use a related skill in the `engineering_agentops` domain.
RULE: Never block workflow — always suggest manual alternative.