Next Devtools Mcp

io.github.vercelPublished by GitHub account vercelv0.3.6Updated Oct 24, 2026

Next.js development tools MCP server with stdio transport

The publisher's own server: Vercel Mcp

VerifiedSTDIODesktop onlyBrowser AutomationDeveloper Tools

Overview

AI-generated overview

Connects coding agents to a running Next.js 16+ dev server so they can read live errors, routes and logs, and points them to bundled docs and browser tooling.

What you can do
  • Discover running Next.js dev servers and list their built-in runtime tools
  • Query a discovered server for build, runtime and type errors, dev logs, page and project metadata, and Server Action sources
  • Locate version-accurate Next.js documentation bundled in the installed package, with fallback guidance when docs are missing
  • Point the agent at the agent-browser CLI for browser automation, with install steps when it is absent
When to use it
Useful when an agent is working on a Next.js 16+ project and needs to see the real state of the running dev server — errors, routes, logs — instead of guessing. Also handy for steering the agent to docs matching the installed Next.js version.
Requirements
Runs locally over stdio via npx; needs Node.js v20.19 or newer and npm or pnpm. The discovery and call tools require a Next.js 16+ dev server running (its MCP endpoint at /_next/mcp is enabled by default). No accounts, API keys or headers are declared.
Before you install
Collects anonymous usage telemetry (tool names, error events, session ID, timestamps, OS and Node.js version) and stores local files under the user's home directory; opt out with NEXT_TELEMETRY_DISABLED. It scans common local ports to find dev servers and reads project files to locate bundled docs. The docs and browser tools only return instructions, so the agent may then run commands such as a global npm install.

Installation

In SourceWeft

  1. Open Next Devtools Mcp in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

Next.js DevTools MCP

[npm next-devtools-mcp package]

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:

bash
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:

json
{  "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
bash
amp mcp add next-devtools -- npx next-devtools-mcp@latest

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

Claude Code
bash
claude mcp add next-devtools npx next-devtools-mcp@latest

Or edit your MCP settings file with the config above.

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

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

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
bash
# Projectgemini mcp add next-devtools npx next-devtools-mcp@latest
# Globalgemini mcp add -s user next-devtools npx next-devtools-mcp@latest
Google Antigravity

Add to .gemini/antigravity/mcp_config.json:

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

See the Antigravity MCP docs.

VS Code / Copilot
bash
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:

bash
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 routesNext 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

ToolWhat it does
nextjs_indexDiscover running Next.js dev servers and list each one's runtime MCP tools.
nextjs_callCall a runtime tool on a discovered server (errors, routes, logs, Server Actions).
nextjs_docsGateway. Point the agent at version-accurate docs in node_modules/next/dist/docs/.
browser_evalGateway. 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
jsonc
{ "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 fetch docs. Recent Next.js releases bundle their docs (markdown, matching your installed version) at node_modules/next/dist/docs/. This tool checks for those files before returning reading instructions. If an installed release has no bundled docs (including early 16.x releases), it offers https://nextjs.org/docs as a fallback and asks the agent to verify APIs against the installed version. Missing dependencies receive installation guidance instead. On Next.js below 16, it recommends npx @next/codemod@latest upgrade latest.

Input: topic (optional), project_path (optional, defaults to cwd). The tool resolves next/package.json from that project, including hoisted workspace dependencies, and returns an absolute docsPath for the installed package.

browser_eval — set up browser automation

Does not drive the browser. It detects whether agent-browser is installed and returns either the entry point (agent-browser skills get core --full) or the install steps (npm install -g agent-browser, then agent-browser install), so the agent runs the CLI directly.

Input: task (optional) — used only to tailor the guidance.

Migrating from 0.3.x

Starting in 0.4.0, next-devtools-mcp is a thin connector.

Changed:

  • nextjs_docs no longer fetches docs over the network. It points the agent at the docs Next.js bundles at node_modules/next/dist/docs/ (or recommends upgrading). The nextjs-docs://llms-index resource is removed.

Removed:

  • init tool — it only enforced the old docs-fetch workflow.
  • upgrade_nextjs_16 and enable_cache_components tools and their prompts — now distributed as agent skills.
  • All cache-components://, nextjs16://, and nextjs-fundamentals:// resources — superseded by the bundled docs.

What remains: nextjs_index, nextjs_call, nextjs_docs, and browser_eval.

Privacy & Telemetry

next-devtools-mcp collects anonymous usage telemetry to improve the tool:

  • Tool usage — which MCP tools are invoked (e.g. nextjs_index, nextjs_call)
  • Error events — anonymous error messages when tools fail
  • Session metadata — session ID, timestamps, basic environment (OS, Node.js version)

Not collected: your code, file contents or paths, personal data, credentials, or tool arguments (only tool names).

Local files live under ~/.next-devtools-mcp/ (anonymous telemetry-id, telemetry-salt, and a debug log mcp.log).

Opt out by setting the environment variable (add it to ~/.zshrc / ~/.bashrc to persist):

bash
export NEXT_TELEMETRY_DISABLED=1

Delete local telemetry data anytime:

bash
rm -rf ~/.next-devtools-mcp

Troubleshooting

ERR_MODULE_NOT_FOUND referencing next-devtools-mcp/dist — clear your npx cache and restart your MCP client. The server reinstalls fresh.

[error] No server info found — nextjs_index / nextjs_call need a running Next.js 16+ dev server:

  1. Start it: npm run dev
  2. Confirm Next.js 16+ (the /_next/mcp endpoint only exists there)
  3. Verify it started without errors

browser_eval and nextjs_docs work without a dev server.

Local Development

bash
git clone https://github.com/vercel/next-devtools-mcp.gitcd next-devtools-mcppnpm installpnpm build

Point your MCP client at the local build:

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

Or with Codex:

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

See the Next.js MCP documentation for how MCP works with Next.js and coding agents.

License

MIT

Source: README.md at commit 1e8dcfa

Tools

0
SourceWeft has not started this package in its sandbox yet, so its tools are not known.

Version history

1
  1. v0.3.6LatestSep 16, 2026

Score

40% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 days25 pts

    Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.

  • Auth declared10 pts

    Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.

  • Tools listed15 pts

    Answer tools/list without a credential, or ship a package that starts in a sandbox without one.

  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts

    Declare a license in the repository or the registry entry.

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