diff --git a/src/app/api/md/[...slug]/route.ts b/src/app/api/md/[...slug]/route.ts
index 5c8866022..51a3d8de6 100644
--- a/src/app/api/md/[...slug]/route.ts
+++ b/src/app/api/md/[...slug]/route.ts
@@ -1,8 +1,19 @@
 import {allPosts} from 'contentlayer/generated';
-import {NextRequest, NextResponse} from 'next/server';
+import {NextResponse} from 'next/server';
+
+// Prerender every post's markdown at build time; unknown slugs 404 without
+// invoking a function.
+export const dynamicParams = false;
+
+export function generateStaticParams() {
+	// The root index.mdx has an empty path; a catch-all needs at least one segment.
+	return allPosts
+		.filter(post => post._raw.flattenedPath !== '')
+		.map(post => ({slug: post._raw.flattenedPath.split('/')}));
+}
 
 export async function GET(
-	_: NextRequest,
+	_: Request,
 	{params}: {params: {slug: string[]}}
 ) {
 	const docPath = params.slug.join('/');
diff --git a/vercel.json b/vercel.json
index 1625d94ae..7e1c6b897 100644
--- a/vercel.json
+++ b/vercel.json
@@ -1,4 +1,5 @@
 {
 	"$schema": "https://openapi.vercel.sh/vercel.json",
+	"fluid": true,
 	"ignoreCommand": "git diff --quiet HEAD^ HEAD -- . ':(exclude).github' ':(exclude).agents' ':(exclude).amp' ':(exclude).vscode' ':(exclude)AGENTS.md' ':(exclude)README.md' ':(exclude).gitignore' ':(exclude)cspell*'"
 }