# Nextjs Server Components

> Use when deciding Server vs Client Component boundaries in Next.js 16, fetching data directly in components, or streaming with Suspense.

- Skill: `fusengine/nextjs-server-components` (Agent Skill, multi-file: 3 files)
- Install (CLI): `npx skillmds@latest add fusengine/nextjs-server-components`
- Raw SKILL.md: https://api.skillmd.com/api/skills/fusengine/nextjs-server-components/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Web & Frontend
- Author: fusengine (https://skillmd.com/u/fusengine)
- Updated: 2026-09-10
- Page: https://skillmd.com/skills/fusengine/nextjs-server-components

---


<objective>
Explains React Server Components as the default rendering model in Next.js 16 with React 19: when to add `'use client'` (hooks, events, browser APIs) versus staying server-only, async Server Components with direct database/file access (no API layer needed), serialization rules for props crossing the server/client boundary (no functions/classes/Dates), and streaming with Suspense boundaries.

Covers composition patterns (passing Server Components as `children` into Client Components), the `server-only` package to prevent accidental secret leakage, parallel data fetching with `Promise.all()`, and caching server computations with `use cache`. Does not cover Next.js routing/caching APIs generally (nextjs-16) or client-side data-fetching libraries (nextjs-tanstack-query) — this skill is specifically about the server/client component boundary itself.
</objective>

# Next.js Server Components

Server Components are the default rendering model in Next.js 16 with React 19.

## Agent Workflow (MANDATORY)

Before ANY implementation, spawn 3 agents in parallel, one `Agent` call each with a `name`:

1. **fuse-ai-pilot:explore-codebase** - Analyze existing component boundaries
2. **fuse-ai-pilot:research-expert** - Verify latest RSC docs via Context7/Exa
3. **mcp__context7__query-docs** - Check Next.js 16 RSC patterns

After implementation, run **fuse-ai-pilot:sniper** for validation.

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## Overview

### When to Use

- Deciding between Server and Client Components
- Fetching data directly in components without API routes
- Implementing streaming and progressive rendering
- Passing data across the server/client boundary
- Using async components with direct database access

### Why Server Components

| Feature | Benefit |
|---------|---------|
| Zero client JS | Components never ship to the browser bundle |
| Direct data access | Query databases, read files without API layer |
| Streaming | Progressive rendering with Suspense boundaries |
| Automatic code splitting | Client Components are lazy-loaded by default |
| SEO-friendly | Full HTML rendered on the server |

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## Critical Rules

1. **Server Components are default** - No directive needed
2. **`'use client'` only when needed** - Hooks, events, browser APIs
3. **Never import server-only into client** - Use `server-only` package
4. **Props must be serializable** - No functions, classes, or Dates across boundary
5. **Async components are server-only** - Client Components cannot be async
6. **Colocate data fetching** - Fetch where the data is consumed

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## Best Practices

1. **Push client boundaries down** - Keep `'use client'` as deep as possible
2. **Composition pattern** - Pass Server Components as `children` to Client
3. **Use `server-only`** - Prevent accidental client imports of secrets
4. **Parallel fetching** - Use `Promise.all()` for independent data
5. **Cache with `use cache`** - Cache expensive server computations
6. **Stream with Suspense** - Wrap slow components for progressive loading

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## Reference Guide

| Need | Reference |
|------|-----------|
| Server vs Client patterns | [rsc-patterns.md](references/rsc-patterns.md) |
| Streaming and Suspense | [streaming.md](references/streaming.md) |
| Data fetching in RSC | [rsc-patterns.md](references/rsc-patterns.md) |
| Loading states | [streaming.md](references/streaming.md) |