[BUG] Next 16 proxy (former middleware) not supported

[fbuireu]

NextJS 16 Proxy file not supported

Looks like the new proxy (new name for middleware in Next 16) file is not supported.

09:23:45.487 | ✘ [ERROR] A request to the Cloudflare API (/accounts/xxxxxx/workers/scripts/xxxxxxx/versions) failed.
-- | --
09:23:45.487 |  
09:23:45.487 | Uncaught TypeError: The argument 'path' The argument must be a file URL object, a file URL string, or an absolute path string.. Received 'undefined'
09:23:45.487 | at null.<anonymous> (node:module:34:15) in createRequire
09:23:45.487 | at null.<anonymous> (file:///opt/buildhome/repo/.open-next/middleware/handler.mjs:1:242)
09:23:45.487 | [code: 10021]
09:23:45.487 | To learn more about this error, visit: https://developers.cloudflare.com/workers/observability/errors/#validation-errors-10021

Steps to reproduce

1. Upgrade to Next 16
2. Rename middleware.ts (or .js) to proxy.ts (or .js)
3. Deploy with opennextjs

Expected behavior

I expect to deploy my site without issues

@opennextjs/cloudflare version

1.11.0

Wrangler version

4.44.0

next info output

Operating System:
  Platform: darwin
  Arch: arm64
  Version: Darwin Kernel Version 24.6.0: Mon Aug 11 21:16:52 PDT 2025; root:xnu-11417.140.69.701.11~1/RELEASE_ARM64_T8112
  Available memory (MB): 24576
  Available CPU cores: 8
Binaries:
  Node: 24.6.0
  npm: 11.6.2
  Yarn: 1.22.22
  pnpm: 10.18.3
Relevant Packages:
  next: 16.0.0 // Latest available version is detected (16.0.0).
  eslint-config-next: N/A
  react: 19.2.0
  react-dom: 19.2.0
  typescript: 5.9.3
Next.js Config:
  output: N/A

Additional context

No response

[nomandhoni-cs]

getting the same problem over here? Found any fix??

[jonra1993]

Hi @nomandhoni-cs I was able to make it deploy using nextjs 16 with the following changes. "This is a temporal solution"

1. Rename proxy.ts by middleware.ts and rename name of function to middleware

This causes just a warning

 ⚠ The "middleware" file convention is deprecated. Please use "proxy" instead. Learn more: https://nextjs.org/docs/messages/middleware-to-proxy

import { updateSession } from "@utils/supabase/proxy";
import type { NextRequest } from "next/server";

export async function middleware(request: NextRequest) {
  const result = await updateSession(request);
  return result;
}

export const config = {
  matcher: [
    /*
     * Match all request paths except for the ones starting with:
     * - _next/static (static files)
     * - _next/image (image optimization files)
     * - favicon.ico (favicon file)
     * Feel free to modify this pattern to include more paths.
     */
    "/((?!_next/static|_next/image|favicon.ico|.*\\.(?:svg|png|jpg|jpeg|gif|webp)$).*)",
  ],
};

2. Edit build script to not use turbo reference

   "build": "next build --webpack",

  "scripts": {
    "dev": "cross-env NODE_OPTIONS=--max_old_space_size=4096 refine dev",
    "build": "refine build --webpack",
    "start": "refine start",
    "lint": "next lint",
    "refine": "refine",
    "generate-types": "node genSupaTypes.js",
    "build:cloudflare": "opennextjs-cloudflare build",
    "preview": "opennextjs-cloudflare build && opennextjs-cloudflare preview",
    "deploy": "opennextjs-cloudflare build && opennextjs-cloudflare deploy",
    "upload": "opennextjs-cloudflare build && opennextjs-cloudflare upload",
    "cf-typegen": "wrangler types --env-interface CloudflareEnv cloudflare-env.d.ts"
  },

[fbuireu]

Hi @nomandhoni-cs I was able to make it deploy using nextjs 16 with the following changes.

1. Rename proxy.ts by middleware.ts and rename name of function to middleware

This causes just a warning

⚠ The "middleware" file convention is deprecated. Please use "proxy" instead. Learn more: https://nextjs.org/docs/messages/middleware-to-proxy
import { updateSession } from "@utils/supabase/proxy";
import type { NextRequest } from "next/server";

export async function middleware(request: NextRequest) {
const result = await updateSession(request);
return result;
}

export const config = {
matcher: [
/*
* Match all request paths except for the ones starting with:
* - _next/static (static files)
* - _next/image (image optimization files)
* - favicon.ico (favicon file)
* Feel free to modify this pattern to include more paths.
/
"/((?!_next/static|_next/image|favicon.ico|.\.(?:svg|png|jpg|jpeg|gif|webp)$).*)",
],
};
2. Edit build script to not use turbo reference
"build": "next build --webpack",

  "scripts": {
    "dev": "cross-env NODE_OPTIONS=--max_old_space_size=4096 refine dev",
    "build": "refine build --webpack",
    "start": "refine start",
    "lint": "next lint",
    "refine": "refine",
    "generate-types": "node genSupaTypes.js",
    "build:cloudflare": "opennextjs-cloudflare build",
    "preview": "opennextjs-cloudflare build && opennextjs-cloudflare preview",
    "deploy": "opennextjs-cloudflare build && opennextjs-cloudflare deploy",
    "upload": "opennextjs-cloudflare build && opennextjs-cloudflare upload",
    "cf-typegen": "wrangler types --env-interface CloudflareEnv cloudflare-env.d.ts"
  },

This solution is only temporary because, although Next.js currently supports both middleware.ts and proxy.ts for backward compatibility, middleware.ts will be discontinued in upcoming versions.

[jonra1993]

Hi @fbuireu Yes I totally agree this is going to work on nextjs 16.0.1 if they remove support to middleware in future releases this is not going to work anymore. The real long term solution is that opennextjs add support to proxy

[vicb]

See #972