Next.js DevTools MCP

next-devtools-mcp is a Model Context Protocol (MCP) server that connects coding agents like Claude and Cursor to your running Next.js dev server.

It is a thin connector. It discovers running Next.js 16+ dev servers and proxies their built-in MCP endpoint (/_next/mcp) so agents get live runtime errors, routes, and logs. It also ships two gateways that point agents at tools they run directly: version-accurate docs and the agent-browser CLI.

[!NOTE] Docs and migration workflows no longer live in this server. Next.js bundles its own docs at node_modules/next/dist/docs/, and upgrade / Cache Components workflows are distributed as agent skills. See Migrating from 0.3.x.

Requirements

• Node.js v20.19 or a newer LTS version
• npm or pnpm
• Next.js 16+ with a running dev server (for nextjs_index / nextjs_call)

Install

Install for all your coding agents with add-mcp:

npx add-mcp next-devtools-mcp@latest

Add -y to skip the prompt and install to all detected agents. Add -g to install globally across all projects.

Or add the config to your MCP client manually:

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

[!NOTE] next-devtools-mcp@latest keeps your client on the latest version.

Client-specific setup

Amp

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

Or follow Amp's MCP docs with the config above.

Claude Code

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

Or edit your MCP settings file with the config above.

Codex

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

Windows 11: add environment variables and a longer startup timeout to .codex/config.toml:

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

Cursor

Install in Cursor

Or go to Cursor Settings → MCP → New MCP Server and use the config above.

Gemini

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

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

Google Antigravity

Add to .gemini/antigravity/mcp_config.json:

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

See the Antigravity MCP docs.

VS Code / Copilot

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

Or follow the official VS Code MCP setup guide.

Warp

Settings | AI | Manage MCP Servers → + Add:

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

Quick Start

Start your Next.js dev server:

npm run dev

Next.js 16+ enables its MCP endpoint by default at http://localhost:3000/_next/mcp. next-devtools-mcp discovers and connects to it automatically — no config needed.

Then ask your agent about the running app:

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?

The agent calls nextjs_index to discover servers, then nextjs_call to query their real state.

Tools

Tool	What it does
nextjs_index	Discover running Next.js dev servers and list each one's runtime MCP tools.
nextjs_call	Call a runtime tool on a discovered server (errors, routes, logs, Server Actions).
nextjs_docs	Gateway. Point the agent at version-accurate docs in node_modules/next/dist/docs/.
browser_eval	Gateway. Point the agent at the agent-browser CLI for browser automation.

The gateways do not do the work themselves — they tell the agent where the docs are or how to install/run the CLI, and the agent runs it directly (faster than proxying through MCP).

nextjs_index — discover servers

Scans common ports for running Next.js 16+ dev servers and lists each server's built-in runtime tools at /_next/mcp. No parameters.

Runtime tools exposed by Next.js (varies by version):

• get_errors — current build, runtime, and type errors
• get_logs — path to the dev log file (browser console + server output)
• get_page_metadata — routes, pages, component metadata
• get_project_metadata — project structure, config, dev server URL
• get_server_action_by_id — resolve a Server Action ID to its source file

Output: JSON listing discovered servers (port, PID, URL) and their tools.

nextjs_call — run a runtime tool

Calls one runtime tool on a discovered server. Run nextjs_index first to find the port and tool name.

Input:

• port (required) — dev server port
• toolName (required) — runtime tool to invoke
• args (optional) — arguments object, only if the tool requires them

{ "port": 3000, "toolName": "get_errors" }

Output: JSON with the tool's result. Upstream requests, including response-body reads, have a 60-second deadline. Cancelling an MCP request aborts its upstream network work; discovery also releases response bodies used only to detect the protocol.

nextjs_docs — find version-accurate docs

Does **not