Next.js 15 App Router + React 19 Server Actions .cursorrules
Transforms Cursor, Windsurf, and Claude into an elite Next.js 15 Staff Frontend Engineer. Enforces zero waterfall fetches, server-first data architecture, and optimistic UI.
Parametric Customizer & Compiler Live Tool
Adjust the variables below. The prompt code and API payload update dynamically in real time.
Specifies stateful mutation pattern.
You are a Principal Frontend Architect specializing in Next.js 15 App Router and React 19. STACK MANDATES: - Framework: Next.js 15 (Turbopack, async Request APIs, headers() and cookies() as async Promises) - UI Library: React 19 Server Components by default; only add 'use client' for interactive state or browser events - Form & Mutation Architecture: React 19 useActionState with optimistic updates via useOptimistic - Styling: Tailwind CSS v4 with mobile-first semantic classes - Validation: Strict Zod schemas for all Server Action inputs and route parameters STRICT CODING RULES: 1. ASYNC REQUEST APIS: In Next.js 15, `cookies()`, `headers()`, `params`, and `searchParams` are asynchronous Promises. Always await them. 2. NO UNINTENTIONAL CLIENT BUNDLES: Keep data fetching exclusively on the server. Never pass sensitive keys or huge payload objects across the RSC serialization boundary. 3. ERROR BOUNDARIES: Always colocate `error.tsx`, `loading.tsx`, and `not-found.tsx` for each route segment. 4. SAFE ACTION CLIENT: Wrap all Server Actions in a type-safe action client handling session auth and input validation.
Supercharge Next.js 15 development with full codebase indexing in Cursor.
Leonardo Phoenix & Flux: Generate photorealistic studio assets with 150 daily free credits. Zero setup required.
πΈ Real Sample Outputs & Verified Results
Visual evidence and benchmark responses generated using this exact prompt formula.
π¬ Prompt Engineering Anatomy
Why this prompt consistently delivers high-tier results: technical parameter breakdown.
Next.js 15 Async Params Resolution In Next.js 15, route `params` is a Promise. Synchronously accessing `props.params.slug` will throw a runtime error in Turbopack.
React 19 useActionState Hook Replaces legacy `useFormState` from ReactDOM. Accepts an action function and initial state, returning `[state, formAction, isPending]`.
π¬ Frequently Asked Questions
Troubleshooting common edge cases, model incompatibilities, and best practices.
Does this work with Cursor and Windsurf?
Yes! Save this into `.cursorrules` in your Next.js project root, and Cursor will automatically enforce Next.js 15 syntax without hallucinating Next.js 13/14 deprecated methods.
How are cookies handled in Next.js 15?
In Next.js 15, `const cookieStore = await cookies()` requires an await before calling `.get()` or `.set()`.
Cursor AI & Claude 3.5 Sonnet Pro Bundle
Supercharge your workflow with instant codebase indexing, multi-file edits, and automated system rules.
Explore Related AI Coding & Architecture Prompts View all β
Claude 3.5 Sonnet Senior Staff Full-Stack Refactoring Architect
Specialized prompt framework for Claude 3.5 Sonnet and Claude 3.7. Transforms messy legacy codebases into modular, testable, high-performance systems with automated regression tests.
cursorCursor AI (.cursorrules) for Next.js 15, React 19 & Tailwind CSS
Stops Cursor from writing outdated Next.js 13 patterns, Pages Router syntax, or deprecated React hooks. Enforces strict TypeScript, Server Actions, and modular clean architecture.
deepseekDeepSeek-R1 Autonomous Deep Research & Synthesis Engine
DeepSeek-R1 chain-of-thought framework designed to force deep reflection, counterfactual auditing, and hypothesis testing before producing production-ready research reports.