N

NextJS

Official
vercel

Provides Next.js development tools and utilities for AI coding assistants, including runtime diagnostics, automated upgrades, and access to official documentation.

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What it does

  • Search and retrieve Next.js official documentation
  • Upgrade Next.js projects to version 16
  • Automate browser testing with Playwright integration
  • Discover running Next.js development servers
  • Enable Cache Components mode for Next.js 16
  • Call MCP tools on running dev servers

Best for

Next.js developers using AI coding assistantsUpgrading legacy Next.js projectsDebugging Next.js applications with AI help
Official Next.js documentation integrationAutomated upgrade utilitiesReal-time runtime diagnostics

Tools (7)

browser_eval

Automate and test web applications using Playwright browser automation. This tool connects to playwright-mcp server and provides access to all Playwright capabilities. CRITICAL FOR PAGE VERIFICATION: When verifying pages in Next.js projects (especially during upgrades or testing), you MUST use browser automation to load pages in a real browser instead of curl or simple HTTP requests. This is because: - Browser automation actually renders the page and executes JavaScript (curl only fetches HTML) - Detects runtime errors, hydration issues, and client-side problems that curl cannot catch - Verifies the full user experience, not just HTTP status codes - Captures browser console errors and warnings via console_messages action IMPORTANT FOR NEXT.JS PROJECTS: If working with a Next.js application, PRIORITIZE using the 'nextjs_index' and 'nextjs_call' tools instead of browser console log forwarding. Next.js has built-in MCP integration that provides superior error reporting, build diagnostics, and runtime information directly from the Next.js dev server. Only use browser_eval's console_messages action as a fallback when these Next.js tools are not available or when you specifically need to test client-side browser behavior that Next.js runtime cannot capture. Available actions: - start: Start browser automation (automatically installs if needed). Verbose logging is always enabled. - navigate: Navigate to a URL - click: Click on an element - type: Type text into an element - fill_form: Fill multiple form fields at once - evaluate: Execute JavaScript in browser context - screenshot: Take a screenshot of the page - console_messages: Get browser console messages (for Next.js, prefer nextjs_index/nextjs_call tools instead) - close: Close the browser - drag: Perform drag and drop - upload_file: Upload files - list_tools: List all available browser automation tools from the server Note: The playwright-mcp server will be automatically installed if not present.

enable_cache_components

Migrate Next.js applications to Cache Components mode and complete setup for Next.js 16. Use this tool when you need to: - Migrate to Cache Components mode - Migrate to cache components - Enable Cache Components - Set up Cache Components - Convert to Cache Components This tool handles ALL steps for migrating and enabling Cache Components: - Configuration: Updates cacheComponents flag (experimental in 16.0.0, stable in canary > 16), removes incompatible flags - Dev Server: Starts dev server (MCP is enabled by default in Next.js 16+) - Error Detection: Loads all routes via browser automation, collects errors using Next.js MCP - Automated Fixing: Adds Suspense boundaries, "use cache" directives, generateStaticParams, cacheLife profiles, cache tags - Verification: Validates all routes work with zero errors Key Features: - One-time dev server start (no restarts needed) - Automated error detection using Next.js MCP tools - Browser-based testing with browser automation - Fast Refresh applies fixes instantly - Comprehensive fix strategies for all error types - Support for "use cache", "use cache: private", Suspense boundaries - Cache invalidation with cacheTag() and cacheLife() configuration Requires: - Next.js 16.0.0+ (stable or canary only - beta versions are NOT supported) - Clean working directory preferred - Browser automation installed (auto-installed if needed) This tool embeds complete knowledge base for: - Cache Components mechanics - Error patterns and solutions - Caching strategies (static vs dynamic) - Advanced patterns (cacheLife, cacheTag, draft mode) - Build behavior and prefetching - Test-driven patterns from 125+ fixtures

init

⚠️ CALL THIS FIRST - Initialize Next.js DevTools MCP context and establish MANDATORY documentation requirements. **IMPORTANT: This tool MUST be called at the START of every Next.js development session.** This tool fetches the latest Next.js documentation and establishes ABSOLUTE requirements for using the nextjs_docs tool for ALL Next.js-related queries. Key Points: - Fetches latest Next.js LLM documentation from nextjs.org - Establishes MANDATORY requirement to use nextjs_docs for ALL Next.js concepts - Instructs AI to forget any prior Next.js knowledge and always query docs - Documents all available MCP tools (nextjs_docs, nextjs_index, nextjs_call, browser_eval, upgrade_nextjs_16, enable_cache_components) Use this tool at the beginning of a Next.js session to: - Reset AI's Next.js knowledge baseline - Ensure 100% documentation-first approach with no exceptions - Understand available tools and their use cases - Follow best practices for Next.js development

nextjs_docs

Search and retrieve Next.js official documentation. Three actions: 1) 'get' - Fetch full docs with a path (preferred after init). 2) 'search' - Find docs by keyword (redirects to use llms.txt index if init was called). 3) 'force-search' - Bypass init check and force API search (escape hatch only). After calling init, prefer using 'get' directly with paths from the llms.txt index.

nextjs_index

Discover all running Next.js development servers and list their available MCP tools. WHEN TO USE THIS TOOL - Use proactively in these scenarios: 1. **Before implementing ANY changes to the app**: When asked to add, modify, or fix anything in the application: - "Add a loading state" → Check current component structure and routes first - "Fix the navigation" → Inspect existing routes and components - "Update the API endpoint" → Query current routes and data flows - "Add error handling" → Check runtime errors and component hierarchy - "Refactor the auth logic" → Inspect current auth implementation and routes - "Optimize performance" → Check runtime diagnostics and component tree Use this to understand where changes should be made and what currently exists. 2. **For diagnostic and investigation questions**: - "What's happening?" / "What's going on?" / "Why isn't this working?" - "Check the errors" / "See what's wrong" - "What routes are available?" / "Show me the routes" - "Clear the cache" / "Reset everything" - Questions about build status, compilation errors, or runtime diagnostics 3. **For agentic codebase search**: Use this as FIRST CHOICE for searching the currently running app. If not found, fallback to static codebase search tools. KEY PRINCIPLE: If the request involves the running Next.js application (whether to investigate OR modify it), query the runtime FIRST to understand current state before proceeding. REQUIREMENTS: - Next.js 16 or later (MCP support was added in v16) - If you're on Next.js 15 or earlier, use the 'upgrade-nextjs-16' MCP prompt to upgrade first Next.js 16+ exposes an MCP (Model Context Protocol) endpoint at /_next/mcp automatically when the dev server starts. No configuration needed - MCP is enabled by default in Next.js 16 and later. This tool discovers all running Next.js servers and returns: - Server port, PID, and URL - Complete list of available MCP tools for each server - Tool descriptions and input schemas After calling this tool, use 'nextjs_call' to execute specific tools. [IMPORTANT] If auto-discovery returns no servers: 1. Ask the user which port their Next.js dev server is running on 2. Call this tool again with the 'port' parameter set to the user-provided port If the MCP endpoint is not available: 1. Ensure you're running Next.js 16 or later (use the 'upgrade-nextjs-16' prompt to upgrade) 2. Verify the dev server is running (npm run dev) 3. Check that the dev server started successfully without errors

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