Support default locale without prefix only for root path

[oleh-dutchenko]

I’m trying to configure next-intl v4 with custom routing.

Requirements
• Default locale is uk (Ukrainian).
• Root / should serve Ukrainian content without a prefix.
• Other locales (e.g. en) should always use a prefix (/en).
• All other pages should still include the prefix (/uk/..., /en/...).

Current attempt

import { defineRouting } from 'next-intl/routing';

export const routing = defineRouting({
  locales: ['uk', 'en'],
  defaultLocale: 'uk',
  localePrefix: 'always',
  pathnames: {
    '/': {
      uk: '/',
      en: '/en'
    }
  }
});

Problem
• pathnames only affects localized slugs, but does not control whether a prefix is added.
• With localePrefix: 'always', the root becomes /uk instead of /.
• With localePrefix: 'as-needed', all Ukrainian routes lose the prefix, not just the root.

Question
• Is there a supported way in next-intl to make only the root path (/) skip the locale prefix, while all other pages keep /uk/...?
• Or is the only workaround to handle this in middleware.ts (rewrite / → /uk and redirect /uk → /)?

[oleh-dutchenko]

My current working solution is implemented via a custom middleware.ts.
I delegate everything to next-intl/middleware, but add two rules for the root path and default locale redirect:

// src/services/i18n/routing.ts

import { defineRouting } from 'next-intl/routing';

export const routing = defineRouting({
  locales: ['uk', 'en'],
  defaultLocale: 'uk',
  localePrefix: 'always',
});

// src/services/i18n/middleware.ts

import createMiddleware from 'next-intl/middleware';
import { NextRequest, NextResponse } from 'next/server';
import { routing } from './routing';

export function createI18nMiddleware(request: NextRequest): NextResponse {
  const { pathname } = request.nextUrl;

  if (pathname === `/${routing.defaultLocale}` || pathname === `/${routing.defaultLocale}/`) {
    const url = request.nextUrl.clone();
    url.pathname = '/';
    return NextResponse.redirect(url, 308);
  }

  if (pathname === '/' || pathname === '') {
    const url = request.nextUrl.clone();
    url.pathname = `/${routing.defaultLocale}`;
    return NextResponse.rewrite(url);
  }

  const handleI18nRouting = createMiddleware(routing);
  return handleI18nRouting(request);
}

This works as expected:
• / serves content in Ukrainian (defaultLocale) without a prefix.
• /uk redirects to / (canonical).
• All other routes still follow the localePrefix: 'always' rule.

[amannn]

That looks like what I'd suggest too!

Alternate links is maybe something you want to adapt in this case or provide your own implementation (e.g. in a sitemap).

[oleh-dutchenko]

Thanks for confirming!
Good to know that handling this via middleware.ts is the viable approach