composition-patterns

A set of design patterns for building reusable React components, the building blocks of React interfaces. It covers compound components, shared context, state organization, and React 19 APIs.

In plain words
What is it for?
Use it when designing component libraries, refactoring complex components, reviewing component structure, or building flexible component interfaces.
Why use it?
It helps replace components crowded with many yes-or-no settings with clearer ways to combine and reuse them.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/practicalswan/agent-skills/composition-patterns
Any agent
npx skills add PracticalSwan/agent-skills --skill composition-patterns
Clone the repo
git clone --depth 1 https://github.com/PracticalSwan/agent-skills

Made for: Claude Code, Codex.

Per session 55 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,152 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00055 $0.01152
Opus 5 $0.00028 $0.00576
Sonnet 5 $0.00011 $0.00230
Haiku 4.5 $0.00006 $0.00115

Measured 2d ago against content hash 9899c40783a4, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

composition-patterns scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

composition-patterns/SKILL.md · 133 lines

How it starts

The opening of the file, as written. The whole thing — 133 lines — stays where its author put it; the contents beside it link to each section on GitHub.

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()

Read the full file on GitHub · 133 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 133 lines · 55 tokens per session scan A 9899c40783a4

Subscribe to this mod's changes

composition-patterns is a skill published in the GitHub repository PracticalSwan/agent-skills (11 stars, last pushed 3d ago), licensed MIT. It adds 55 tokens to every session and 1,152 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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