Your AI assistant can now read the Next.js dev server

What it does

next-devtools-mcp is a Model Context Protocol server from Vercel that plugs AI coding agents into Next.js projects. It bundles three things: a searchable interface to official Next.js documentation, Playwright-driven browser automation, and—if you’re running Next.js 16+—live runtime diagnostics pulled straight from the dev server. Agents query your actual app state rather than guessing from static files.

The interesting bit

Next.js 16+ enables an MCP endpoint at /_next/mcp by default; this server auto-discovers it and exposes tools that let agents query the running dev server directly. That means your assistant can ask what errors just fired, inspect routes, or read logs without you copy-pasting stack traces.

Key highlights

• Auto-discovers local Next.js 16+ dev servers for real-time runtime introspection via nextjs_index and nextjs_call
• Built-in nextjs_docs tool searches and retrieves official Next.js documentation with App Router or Pages Router filtering
• browser_eval wraps Playwright to navigate, screenshot, and capture console messages during verification
• On-demand knowledge base resources for Cache Components and Next.js 16 migration to avoid stuffing the context window
• Supports a wide roster of agents: Claude, Cursor, Codex, Gemini, VS Code Copilot, Warp, and others

Caveats

• Full runtime diagnostics require Next.js 16+; older projects get documentation and automation tools only
• Every session must start with an explicit init tool call unless you manually configure auto-initialization rules in your agent’s config

Verdict

Worth adding if you routinely ask AI agents to debug Next.js apps and want them to stop hallucinating API changes. Skip it if you don’t use an MCP-compatible coding agent or your framework of choice is something else entirely.