Next - DevTools - MCP: MCP Server Integrating Claude & Cursor for Next.js Dev & Diagnosis

Next Devtools MCP

The Next.js development tools MCP server provides Next.js development tools and utilities for AI programming assistants such as Claude and Cursor, including runtime diagnostics, development automation, and document access functions.

Developer tools Artificial intelligence chatbots #Next.js Development #AI Assistant Tools #Development Automation #Runtime Diagnostics .TypeScript

rating : 5 points

downloads : 6.2K

update time : 2025-12-29

Open Site

What is Next.js DevTools MCP?

Next.js DevTools MCP is a bridge server that connects AI programming assistants with the Next.js development environment. It allows AI assistants to directly access the state of a running Next.js application, query official documentation, perform automated upgrade tasks, and conduct browser testing. It is particularly suitable for use with AI programming tools such as Claude Code, Cursor, and VS Code Copilot.

How to use Next.js DevTools MCP?

The usage is divided into three simple steps: 1) Add the server to the MCP configuration of the AI assistant; 2) Start the Next.js development server (Next.js 16+); 3) Invoke various tools through the AI assistant for development, debugging, and document query. For Next.js 16+ projects, the server will automatically discover and connect to the running application.

Use cases

It is most suitable for the following scenarios: 1) Developing Next.js projects using an AI assistant; 2) Needing real-time diagnosis of application errors and status; 3) Upgrading the Next.js version to 16+; 4) Enabling and configuring the Cache Components feature; 5) Querying the official Next.js documentation and best practices; 6) Automating browser testing and verification.

🚀 Next.js DevTools MCP

next-devtools-mcp is a Model Context Protocol (MCP) server that offers Next.js development tools and utilities for coding agents such as Claude and Cursor. It serves as a bridge between coding agents and Next.js development resources, enabling seamless interaction and enhanced development experiences.

🚀 Quick Start

Requirements

Node.js v20.19 or a newer latest maintenance LTS version
npm or pnpm

Add the following configuration to your MCP client:

{
  "mcpServers": {
    "next-devtools": {
      "command": "npx",
      "args": ["-y", "next-devtools-mcp@latest"]
    }
  }
}

⚠️ Important Note

Using next-devtools-mcp@latest ensures that your MCP client will always use the latest version of the Next.js DevTools MCP server.

MCP Client Configuration

Amp

Using Amp CLI:

amp mcp add next-devtools -- npx next-devtools-mcp@latest

Or configure manually: Follow Amp's MCP documentation and apply the standard configuration shown above.

Claude Code

Use the Claude Code CLI to add the Next.js DevTools MCP server:

claude mcp add next-devtools npx next-devtools-mcp@latest

Alternatively, manually configure Claude by editing your MCP settings file and adding the configuration shown above.

Codex

Using Codex CLI:

codex mcp add next-devtools -- npx next-devtools-mcp@latest

Or configure manually: Follow the MCP setup guide with the standard configuration format:

Command: npx
Arguments: -y, next-devtools-mcp@latest

Windows 11 Special Configuration: Update .codex/config.toml with environment variables and increased startup timeout:

env = { SystemRoot="C:\\Windows", PROGRAMFILES="C:\\Program Files" }
startup_timeout_ms = 20_000

Cursor

Click the button to install: Install in Cursor

Or install manually: Go to Cursor Settings → MCP → New MCP Server. Use the config provided above.

Gemini

Using Gemini CLI:

Project-wide installation:

gemini mcp add next-devtools npx next-devtools-mcp@latest

Global installation:

gemini mcp add -s user next-devtools npx next-devtools-mcp@latest

Or configure manually: Follow the MCP setup guide with these parameters:

Command: npx
Arguments: -y, next-devtools-mcp@latest

VS Code / Copilot

Using VS Code CLI:

code --add-mcp '{"name":"next-devtools","command":"npx","args":["-y","next-devtools-mcp@latest"]}'

Or configure manually: Follow the official VS Code MCP server setup guide and add the Next.js DevTools server through VS Code settings.

Warp

Using Warp UI: Navigate to Settings | AI | Manage MCP Servers and select + Add to register a new MCP server with the following configuration:

Name: next-devtools
Command: npx
Arguments: -y, next-devtools-mcp@latest

For Next.js 16+ Projects (Recommended)

To unlock the full power of runtime diagnostics, start your Next.js dev server:

npm run dev

Next.js 16+ has MCP enabled by default at http://localhost:3000/_next/mcp (or whichever port your dev server uses). The next-devtools-mcp server will automatically discover and connect to it.

⚠️ IMPORTANT: Start every Next.js session by calling the init tool to set up proper context:

Use the init tool to set up Next.js DevTools context

This initializes the MCP context and ensures the AI assistant uses official Next.js documentation for all queries.

After initialization, try these prompts to explore runtime diagnostics:

Next Devtools, what errors are in my Next.js application?

Next Devtools, show me the structure of my routes

Next Devtools, what's in the development server logs?

Your coding agent will use the nextjs_index and nextjs_call tools to query your running application's actual state.

For All Next.js Projects

You can use the development automation and documentation tools regardless of Next.js version:

Next Devtools, help me upgrade my Next.js app to version 16

Next Devtools, enable Cache Components in my Next.js app

Next Devtools, search Next.js docs for generateMetadata

💡 Pro Tip: Auto-Initialize on Every Session

To make your AI assistant automatically call the init tool at the start of every Next.js session without being asked, add this instruction to your agent's configuration file:

Claude Code / Claude Desktop

Add to ~/.claude/CLAUDE.md (global) or ./.claude/CLAUDE.md (project-specific):

**When starting work on a Next.js project, ALWAYS call the `init` tool from
next-devtools-mcp FIRST to set up proper context and establish documentation
requirements. Do this automatically without being asked.**

Cursor

Add to .cursorrules in your project root or global Cursor settings:

When working with Next.js, always call the init tool from next-devtools-mcp
at the start of the session to establish proper context and documentation requirements.

Codex / Other AI Coding Assistants

Add to your agent's configuration file (e.g., .codex/instructions.md, agent.md, or similar):

**Next.js Initialization**: When starting work on a Next.js project, automatically
call the `init` tool from the next-devtools-mcp server FIRST. This establishes
proper context and ensures all Next.js queries use official documentation.

Why this matters:

✅ Ensures consistent context across all Next.js work
✅ Automatically establishes the documentation-first requirement
✅ No need to manually call init every time
✅ Works across all your Next.js projects

✨ Features

This MCP server provides coding agents with comprehensive Next.js development capabilities through three primary mechanisms:

1. Runtime Diagnostics & Live State Access (Next.js 16+)

Connect directly to your running Next.js dev server's built-in MCP endpoint to query:

Real-time build and runtime errors
Application routes, pages, and component metadata
Development server logs and diagnostics
Server Actions and component hierarchies

2. Development Automation

Tools for common Next.js workflows:

Automated Next.js 16 upgrades with official codemods
Cache Components migration and setup with error detection and automated fixes
Browser testing integration via Playwright for visual verification

3. Knowledge Base & Documentation

Curated Next.js 16 knowledge base (12 focused resources on Cache Components, async APIs, etc.)
Direct access to official Next.js documentation via search API
Pre-configured prompts for upgrade guidance and Cache Components enablement

💡 Usage Tip

See the Next.js MCP documentation for details on how MCP servers work with Next.js and coding agents.

📦 Installation

Local Development

To run the MCP server locally for development:

Clone the repository
Install dependencies:
```
pnpm install
pnpm build
```

Configure your MCP client to use the local version:

{
  "mcpServers": {
    "next-devtools": {
      "command": "node",
      "args": ["/absolute/path/to/next-devtools-mcp/dist/index.js"]
    }
  }
}

Note: Replace /absolute/path/to/next-devtools-mcp with the actual absolute path to your cloned repository.

or manually add, e.g. with codex:

codex mcp add next-devtools-local -- node dist/index.js

💻 Usage Examples

Using the `init` Tool

Use the init tool to set up Next.js DevTools context

Exploring Runtime Diagnostics

Next Devtools, what errors are in my Next.js application?

Next Devtools, show me the structure of my routes

Next Devtools, what's in the development server logs?

Development Automation

Next Devtools, help me upgrade my Next.js app to version 16

Next Devtools, enable Cache Components in my Next.js app

Searching Documentation

Next Devtools, search Next.js docs for generateMetadata

📚 Documentation

MCP Resources

The knowledge base resources are automatically available to your coding agent and are split into focused sections for efficient context management. Current resource URIs:

📚 Available Knowledge Base Resources (click to expand)

Cache Components (12 sections):
- cache-components://overview
- cache-components://core-mechanics
- cache-components://public-caches
- cache-components://private-caches
- cache-components://runtime-prefetching
- cache-components://request-apis
- cache-components://cache-invalidation
- cache-components://advanced-patterns
- cache-components://build-behavior
- cache-components://error-patterns
- cache-components://test-patterns
- cache-components://reference
Next.js 16 migration:
- nextjs16://migration/beta-to-stable
- nextjs16://migration/examples
Next.js fundamentals:
- nextjs-fundamentals://use-client

Resources are loaded on-demand by your coding agent, providing targeted knowledge without overwhelming the context window.

MCP Prompts

Pre-configured prompts to help with common Next.js development tasks:

💡 Available Prompts (click to expand)

upgrade-nextjs-16 - Guide for upgrading to Next.js 16
enable-cache-components - Migrate and enable Cache Components mode for Next.js 16

MCP Tools

init

Initialize Next.js DevTools MCP context and establish documentation requirements.

Capabilities:

Sets up proper context for AI assistants working with Next.js
Establishes requirement to use nextjs_docs for ALL Next.js-related queries
Documents all available MCP tools and their use cases
Provides best practices for Next.js development with MCP
Includes example workflows and quick start checklist

When to use:

At the beginning of a Next.js development session
To understand available tools and establish proper context
To ensure documentation-first approach for Next.js development

Input:

project_path (optional) - Path to Next.js project (defaults to current directory)

Output:

Comprehensive initialization context and guidance for Next.js development with MCP tools

nextjs_docs

Search and retrieve Next.js official documentation and knowledge base.

Capabilities:

Two-step process: 1) Search for docs by keyword to get paths, 2) Fetch full markdown content by path
Uses official Next.js documentation search API
Provides access to comprehensive Next.js guides, API references, and best practices
Supports filtering by router type (App Router, Pages Router, or both)

Input:

action (required) - Action to perform: search to find docs, get to fetch full content
query (optional) - Required for search. Keyword search query (e.g., 'metadata', 'generateStaticParams', 'middleware')
path (optional) - Required for get. Doc path from search results (e.g., '/docs/app/api-reference/functions/refresh')
anchor (optional) - Optional for get. Anchor/section from search results (e.g., 'usage')
routerType (optional) - For search only. Filter by: app, pages, or all (default: all)

Output:

Search results with doc titles, paths, content snippets, sections, and anchors
Full markdown content for specific documentation pages

browser_eval

Automate and test web applications using Playwright browser automation.

When to use:

Verifying pages in Next.js projects (especially during upgrades or testing)
Testing user interactions and flows
Taking screenshots for visual verification
Detecting runtime errors, hydration issues, and client-side problems
Capturing browser console errors and warnings

Important: For Next.js projects, prioritize using the nextjs_index and nextjs_call tools instead of browser console log forwarding. Only use browser_eval's console_messages action as a fallback when these tools are not available.

Available actions:

start - Start browser automation (automatically installs if needed)
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
close - Close the browser
drag - Perform drag and drop
upload_file - Upload files
list_tools - List all available browser automation tools from the server

Input:

action (required) - The action to perform
browser (optional) - Browser to use: chrome, firefox, webkit, msedge (default: chrome)
headless (optional) - Run browser in headless mode (default: true)
Action-specific parameters (see tool description for details)

Output:

JSON with action result, screenshots (base64), console messages, or error information

nextjs_index

Discover all running Next.js dev servers and list their available MCP tools.

What this tool does:

Automatically discovers all running Next.js 16+ dev servers on your machine and lists the runtime diagnostic tools available from each server's built-in MCP endpoint at /_next/mcp.

No parameters required - Just call the tool and it will scan for servers.

Available Next.js Runtime Tools (varies by Next.js version):

get_errors - Get current build, runtime, and type errors
get_logs - Get path to development log file (browser console + server output)
get_page_metadata - Query application routes, pages, and component metadata
get_project_metadata - Get project structure, config, and dev server URL
get_server_action_by_id - Look up Server Actions by ID to find source files

Requirements:

Next.js 16+ (MCP enabled by default)
Running dev server (npm run dev)

Output:

JSON with list of discovered servers, each containing:
- Port, PID, URL
- Available tools with descriptions and input schemas

Example prompts:

"Next Devtools, what servers are running?"
"Next Devtools, show me available diagnostic tools"

nextjs_call

Execute a specific MCP tool on a running Next.js dev server.

What this tool does:

Calls a specific runtime diagnostic tool on a Next.js 16+ dev server's built-in MCP endpoint at /_next/mcp.

Input Parameters:

port (required) - Dev server port (use nextjs_index first to discover)
toolName (required) - Name of the Next.js tool to invoke
args (optional) - Arguments object for the tool (only if required by that tool)

Requirements:

Next.js 16+ (MCP enabled by default)
Running dev server (npm run dev)
Use nextjs_index first to discover available servers and tools

Typical workflow:

// Step 1: Discover servers and tools
// (call nextjs_index first)

// Step 2: Call a specific tool
{
  "port": 3000,
  "toolName": "get_errors"
  // args is optional and only needed if the tool requires parameters
}

Output:

JSON with tool execution results

Example prompts that use this tool:

"Next Devtools, what errors are in my Next.js app?"
"Next Devtools, show me my application routes"
"Next Devtools, what's in the dev server logs?"
"Next Devtools, find the Server Action with ID xyz"

upgrade_nextjs_16

Guides through upgrading Next.js to version 16 with automated codemod execution.

Capabilities:

Runs official Next.js codemod automatically (requires clean git state)
Handles async API changes (params, searchParams, cookies, headers)
Migrates configuration changes
Updates image defaults and optimization
Fixes parallel routes and dynamic segments
Handles deprecated API removals
Provides guidance for React 19 compatibility

Input:

project_path (optional) - Path to Next.js project (defaults to current directory)

Output:

Structured JSON with step-by-step upgrade guidance

enable_cache_components

Complete Cache Components setup, enablement, and migration for Next.js 16 with automated error detection and fixing. This tool is used for migrating Next.js applications to Cache Components mode.

Capabilities:

Pre-flight checks (package manager, Next.js version, configuration)
Enable Cache Components configuration
Start dev server with MCP enabled
Automated route verification and error detection
Automated error fixing with intelligent boundary setup (Suspense, caching directives, static params)
Final verification and build testing

Input:

project_path (optional) - Path to Next.js project (defaults to current directory)

Output:

Structured JSON with complete setup guidance and phase-by-phase instructions

Example Usage:

With Claude Code:

Next Devtools, help me enable Cache Components in my Next.js 16 app

With other agents or programmatically:

{
  "tool": "enable_cache_components",
  "args": {
    "project_path": "/path/to/project"
  }
}

🔧 Technical Details

How It Works

This package provides a bridge MCP server that connects your coding agent to Next.js development tools:

Coding Agent
      ↓
  next-devtools-mcp (this package)
      ↓
      ├─→ Next.js Dev Server MCP Endpoint (/_next/mcp) ← Runtime diagnostics
      ├─→ Playwright MCP Server ← Browser automation
      └─→ Knowledge Base & Tools ← Documentation, upgrades, setup automation

Key Architecture Points:

For Next.js 16+ projects: This server automatically discovers and connects to your running Next.js dev server's built-in MCP endpoint at http://localhost:PORT/_next/mcp. This gives coding agents direct access to runtime errors, routes, logs, and application state.
For all Next.js projects: Provides development automation tools (upgrades, Cache Components setup), documentation access, and browser testing capabilities that work independently of the runtime connection.
Simple workflow: Call nextjs_index to see all servers and available tools, then call nextjs_call with the specific port and tool name you want to execute.