Feature Request: Support Async Route Params in Nested sitemap.ts Files

[bennajah]

Currently, sitemap.ts files in the app directory cannot access or resolve dynamic route parameters, especially in nested or localized routes.

For example, when using a folder structure like this:

app/
[locale]/
sitemap.ts
page.tsx

There’s no way to access the [locale] param inside app/[locale]/sitemap.ts.
This prevents developers from generating localized sitemaps for multilingual or multi-region setups.

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💡 Proposed Solution

Allow sitemap.ts to accept and resolve async route params, similar to how generateMetadata and generateStaticParams work.

Example:

// app/[locale]/sitemap.ts
import type { MetadataRoute } from "next";

export default async function sitemap({
  params,
}: {
  params: Promise<{ locale: string }>;
}): Promise<MetadataRoute.Sitemap> {
  const { locale } = await params;

  return [
    {
      url: `https://example.com/${locale}/about`,
      lastModified: new Date(),
    },
    {
      url: `https://example.com/${locale}/contact`,
      lastModified: new Date(),
    },
  ];
}

Then, the root sitemap could reference all localized sitemaps:

// app/sitemap.ts
import type { MetadataRoute } from "next";

export default function sitemap(): MetadataRoute.Sitemap {
  return [
    { url: "https://example.com/en/sitemap.xml" },
    { url: "https://example.com/fr/sitemap.xml" },
    { url: "https://example.com/es/sitemap.xml" },
  ];
}

---

✅ Benefits

Enables localized SEO by generating per-locale sitemaps.

Keeps sitemap logic consistent with other async functions like generateMetadata.

Reduces duplication and improves maintainability in internationalized projects.

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🧠 Use Case Example

International websites ([locale]/page.tsx) need locale-specific URLs and metadata.

Each locale should have its own sitemap for better indexing by search engines.

Root sitemap.ts should list all localized sitemaps.