Next.js Knowledge Patch (15.3 – 16.x)

Supplementary knowledge for Next.js features released after Claude's training cutoff. Covers versions 15.3 through 16.1 (April 2025 – January 2026).

Request Interception: proxy.ts

Next.js 16 replaces middleware.ts with proxy.ts. Rename the file and export a proxy function instead of middleware. Runs on Node.js runtime by default.

// proxy.ts (project root)
import { NextRequest, NextResponse } from 'next/server';

export function proxy(request: NextRequest) {
  return NextResponse.next();
}

middleware.ts still works (Edge runtime) but is deprecated and will be removed.