diff --git a/apps/docs/app/api/guides-md/[...slug]/route.ts b/apps/docs/app/api/guides-md/[...slug]/route.ts
index b942ff2f73..3e877b3181 100644
--- a/apps/docs/app/api/guides-md/[...slug]/route.ts
+++ b/apps/docs/app/api/guides-md/[...slug]/route.ts
@@ -1,14 +1,15 @@
-import { promises as fs } from 'fs'
-import path from 'path'
+import { promises as fs } from 'node:fs'
+import path from 'node:path'
+import { BASE_PATH, IS_PRODUCTION, PROD_URL } from '~/lib/constants'
 import { NextResponse } from 'next/server'
 
-export async function GET(_request: Request, { params }: { params: Promise<{ slug: string[] }> }) {
+export async function GET(request: Request, { params }: { params: Promise<{ slug: string[] }> }) {
   const { slug } = await params
   const baseDir = path.join(process.cwd(), 'public/docs/guides')
   const filePath = path.join(baseDir, `${slug.join('/')}.md`)
 
   if (!filePath.startsWith(baseDir + path.sep) && filePath !== baseDir) {
-    return new NextResponse('Not found', { status: 404 })
+    return notFoundResponse(request, slug)
   }
 
   try {
@@ -20,6 +21,86 @@ export async function GET(_request: Request, { params }: { params: Promise<{ slu
       },
     })
   } catch {
-    return new NextResponse('Not found', { status: 404 })
+    return notFoundResponse(request, slug)
   }
 }
+
+/**
+ * Resolves the docs base URL from trusted sources only.
+ * Avoids host-header-driven SSRF from request origin.
+ */
+function resolveDocsBaseUrl() {
+  if (IS_PRODUCTION) return PROD_URL
+  if (process.env.VERCEL_URL) return `https://${process.env.VERCEL_URL}${BASE_PATH}`
+  if (process.env.NEXT_PUBLIC_SITE_URL) return `${process.env.NEXT_PUBLIC_SITE_URL}${BASE_PATH}`
+  return undefined
+}
+
+async function notFoundResponse(_request: Request, slug: string[]) {
+  const baseUrl = resolveDocsBaseUrl()
+  const query = slug.join(' ').replace(/[_-]/g, ' ')
+  const suggestions = baseUrl ? await searchForSuggestions(baseUrl, query) : []
+  const markdown = buildNotFoundMarkdown(slug, suggestions)
+  return new NextResponse(markdown, {
+    status: 404,
+    headers: {
+      'Content-Type': 'text/markdown; charset=utf-8',
+      'Cache-Control': 'no-store',
+    },
+  })
+}
+
+interface SearchSuggestion {
+  title: string
+  href: string
+}
+
+async function searchForSuggestions(baseUrl: string, query: string): Promise<SearchSuggestion[]> {
+  try {
+    const response = await fetch(`${baseUrl}/api/graphql`, {
+      method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({
+        query: `
+          query SearchDocs($query: String!) {
+            searchDocs(query: $query, limit: 5) {
+              nodes {
+                title
+                href
+              }
+            }
+          }
+        `,
+        variables: { query },
+      }),
+    })
+
+    if (!response.ok) return []
+
+    const data = await response.json()
+    return (data?.data?.searchDocs?.nodes ?? []).filter(
+      (n: Partial<SearchSuggestion>): n is SearchSuggestion => !!n.title && !!n.href
+    )
+  } catch {
+    return []
+  }
+}
+
+function buildNotFoundMarkdown(slug: string[], suggestions: SearchSuggestion[]): string {
+  const pagePath = slug.join('/')
+
+  const suggestionsMd =
+    suggestions.length > 0
+      ? `## You might be looking for...\n\n${suggestions
+          .map(({ title, href }) => `- [${title}](${href}.md)`)
+          .join('\n')}\n`
+      : ''
+
+  return `# 404 - Page Not Found
+
+The page \`/docs/guides/${pagePath}.md\` does not exist.
+
+${suggestionsMd}
+See also: [Changelog](https://supabase.com/changelog.md)
+`
+}
diff --git a/apps/docs/turbo.jsonc b/apps/docs/turbo.jsonc
index 3c1148eb29..b025460e4a 100644
--- a/apps/docs/turbo.jsonc
+++ b/apps/docs/turbo.jsonc
@@ -30,6 +30,7 @@
         "VERCEL",
         "VERCEL_ENV",
         "VERCEL_GIT_COMMIT_SHA",
+        "VERCEL_URL",
         // These envs are used in the packages
         "NEXT_PUBLIC_STORAGE_KEY",
         "NEXT_PUBLIC_AUTH_DEBUG_KEY",