nextjs - 💡(How to fix) Fix Proxy file build error: “Route segment config is not allowed in Proxy file at './proxy.ts'” with no config export present [1 comments, 2 participants]

Link to the code that reproduces this issue

https://github.com/vercel/next.js/issues

To Reproduce

I am experiencing a persistent build error with Next.js 16.x (tried 16.0.10 and 16.0.8):

My proxy.ts file does not contain any export const config or similar config export. I have only one proxy.ts in my project root, and no proxy.js or middleware.ts files.

Error: Route segment config is not allowed in Proxy file at "./proxy.ts". Proxy always runs on Node.js runtime. Learn more: https://nextjs.org/docs/messages/middleware-to-proxy

proxy.ts:

import { auth } from "@/auth"; import { NextResponse } from "next/server";

export const runtime = "nodejs";

const publicRoutes = [ "/", "/products", "/auth/login", "/auth/register", "/auth/forgot-password", "/auth/reset-password", "/auth/verify-email", "/admin/login", "/user/login", ];

export default auth(async (req) => { const { nextUrl } = req; const isLoggedIn = !!req.auth; const userRole = req.auth?.user?.role as string | undefined; const userId = req.auth?.user?.id;

const isApiAuthRoute = nextUrl.pathname.startsWith("/api/auth"); const isAuthRoute = nextUrl.pathname.startsWith("/auth"); const isAdminRoute = nextUrl.pathname.startsWith("/admin"); const isUserRoute = nextUrl.pathname.startsWith("/user"); const isProtectedRoute = nextUrl.pathname.startsWith("/account") || nextUrl.pathname.startsWith("/orders") || nextUrl.pathname.startsWith("/checkout") || nextUrl.pathname.startsWith("/wishlist");

if (isApiAuthRoute || publicRoutes.includes(nextUrl.pathname)) { return NextResponse.next(); }

// ...rest of logic... return NextResponse.next(); });

Used 1 reference Here’s a ready-to-use template for your GitHub issue to report the persistent proxy.ts build error to the Next.js team:

Current vs. Expected behavior

What I’ve tried:

Removed all config exports from proxy.ts Ensured only one proxy.ts exists in the project root Deleted .next, node_modules, and package-lock.json, then reinstalled everything Tried both Next.js 16.0.10 and 16.0.8 Restarted my IDE and checked for hidden files No proxy.js or middleware.ts present Expected behavior: The build should succeed since there is no config export in proxy.ts.

Actual behavior: Build fails with the above error, even after all cleanups and version changes.

Steps to reproduce:

Use the above proxy.ts in a Next.js 16.x project Run npm run build Environment:

Next.js version: 16.0.10 (also tried 16.0.8) Node.js version: (your version here) OS: (your OS here) Deployment: Local and Render

Steps to reproduce:

Use the above proxy.ts in a Next.js 16.x project Run npm run build Environment:

Next.js version: 16.0.10 (also tried 16.0.8) Node.js version: (your version here) OS: (your OS here) Deployment: Local and Render

Provide environment information

OS windows 11
visual studio code
next and node js
postgres

error occured at npm run build

Which area(s) are affected? (Select all that apply)

Not sure

Which stage(s) are affected? (Select all that apply)

Other (Deployed)

Additional context

Steps to reproduce:

Use the above proxy.ts in a Next.js 16.x project Run npm run build Environment:

Next.js version: 16.0.10 (also tried 16.0.8) Node.js version: (your version here) OS: (your OS here) Deployment: Local and Render