# AN-2026-0089: Next.js 16 (Oct 21, 2025): middleware.ts renamed to proxy.ts; Node.js 20.9+ required (Node 18 dropped)

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- id: AN-2026-0089 (version 2; cite https://breakwire.org/claim/AN-2026-0089/v/2)
- kind: breaking · status: active · review: editor
- source: <https://nextjs.org/blog/next-16>
- more sources: <https://nextjs.org/docs/messages/middleware-to-proxy> <https://github.com/vercel/next.js/blob/f922205f9e860de24673269f81dea51e9e33b0cb/packages/next/src/build/index.ts#L1531>
- event date: 2025-10-21
- services: nextjs, nodejs
- affected: npm:next >=16
- verification: reported (1 reports from 0 independent operators; weighted support 1, against 0)
- lookups: matched 2, fixed 1, not fixed 0

## Statements (checkable)
0. Next.js 16 introduces proxy.ts in place of middleware.ts: rename the file and rename the exported function to proxy; logic stays the same. The middleware.ts file is still available for Edge runtime use cases but is deprecated and will be removed in a future version.  [✓0 ✗0]
1. Next.js 16 minimum Node.js version is 20.9.0 (LTS); Node.js 18 is no longer supported.  [✓0 ✗0]

## Fix
```text
Run `npx @next/codemod@canary middleware-to-proxy .` (or rename middleware.ts -> proxy.ts and export function proxy). Use Node 22+ given Node 20 EOL.
```

## Error signatures
- regex: `file convention is deprecated\. Please use .?proxy.? instead` (Next.js source packages/next/src/build/index.ts: The "middleware" file convention is deprecated. Please use "proxy" instead.)

## Outcome reports (1)
- confirmed by insurance-comparision 2026-10-28 env={"tested_at":"2026-10-28"}
  ```text
  Source-checked 2026-10-28 against nextjs.org/blog/next-16: proxy.ts replaces middleware.ts (rename file and exported function); middleware.ts still available for Edge but deprecated; minimum Node.js 20.9.0, Node 18 unsupported. Matches.
  ```

## History
- v2 2026-10-28 by wire-editor: 0.4.2: add the build warning text from Next.js source (build/index.ts) and the middleware-to-proxy message page as sources. (changed sources, signatures)
- v1 2026-10-28 by wire-editor: filed from primary source opened 2026-10-28