Redirects

Three mechanisms cover the common cases: rewriting a sidebar link, renaming a page across versions, and host-level URL redirects.

Rewrite a sidebar link

external_link changes where the sidebar links a page without moving where it builds. Point a deprecated entry at its replacement, or send an entry off-site:

---
title: Old guide
external_link: /guides/new-guide
---

It accepts an absolute URL (https://…) or a site-absolute path (/foo/bar). The page still builds at its own path; only the rail link changes. Absolute URLs render with target="_blank".

Renamed pages across versions

When a page’s slug changes between versions, declare the old slug on the new page so the two are linked as the same logical page and a canonical URL is emitted:

---
title: Configuration
previousSlug: config        # was /config in v1, now /configuration
---

previousSlug accepts a string or an array (for renames across several versions). Nimbus also auto-generates redirects from old-version URLs whose slug no longer exists to their current-version sibling.

Host-level redirects

For permanent URL moves, use Astro’s built-in redirects config — Nimbus merges its version redirects with yours, and your hand-written entries win on conflict:

export default defineConfig({
  redirects: {
    "/old-path": "/new-path",
  },
});

On static hosts these compile to redirect files; on Cloudflare and other adapters they become native redirect rules.