use vercel preset

.tests/test.vercel.ts

@@ -18,7 +18,7 @@ test("dev", async ({ page, $ }) => {
   const port = await getPort();
   const dev = $(`pnpm dev`, { env: { PORT: String(port) } });
 
-  const url = await matchLine(dev.stdout, urlRegex.custom);
+  const url = await matchLine(dev.stdout, urlRegex.viteDev);
   await workflow({ page, url });
   expect(withoutHmrPortError(dev.buffer.stderr)).toBe("");
 });

vercel/app/routes/home.tsx

@@ -9,7 +9,7 @@ export function meta({}: Route.MetaArgs) {
 }
 
 export function loader({ context }: Route.LoaderArgs) {
-  return { message: context.VALUE_FROM_VERCEL };
+  return { message: "Hello from Vercel" };
 }
 
 export default function Home({ loaderData }: Route.ComponentProps) {

vercel/package.json

@@ -2,28 +2,26 @@
   "private": true,
   "type": "module",
   "scripts": {
-    "build": "react-router build && node vercel/prepare.js",
-    "dev": "cross-env NODE_ENV=development node ./dev-server.js",
+    "build": "react-router build",
+    "dev": "react-router dev",
+    "start": "react-router-serve ./build/server/index.js",
     "typecheck": "react-router typegen && tsc"
   },
   "dependencies": {
-    "@react-router/express": "*",
-    "@react-router/node": "*",
-    "@vercel/node": "^3.2.25",
-    "express": "^4.21.1",
+    "@react-router/node": "^7.1.5",
     "isbot": "^5.1.17",
     "react": "^19.0.0",
     "react-dom": "^19.0.0",
-    "react-router": "*"
+    "react-router": "^7.1.5"
   },
   "devDependencies": {
-    "@react-router/dev": "*",
+    "@react-router/dev": "^7.1.5",
     "@tailwindcss/vite": "^4.0.0",
-    "@types/express": "^5.0.0",
     "@types/node": "^20",
     "@types/react": "^19.0.1",
     "@types/react-dom": "^19.0.1",
-    "cross-env": "^7.0.3",
+    "@vercel/node": "^5.1.2",
+    "@vercel/react-router": "^1.0.2",
     "tailwindcss": "^4.0.0",
     "typescript": "^5.7.2",
     "vite": "^5.4.11",

vercel/react-router.config.ts

@@ -1,7 +1,9 @@
 import type { Config } from "@react-router/dev/config";
+import { vercelPreset } from "@vercel/react-router/vite";
 
 export default {
   // Config options...
   // Server-side render by default, to enable SPA mode set this to `false`
   ssr: true,
+  presets: [vercelPreset()],
 } satisfies Config;

vercel/vite.config.ts

@@ -3,14 +3,7 @@ import tailwindcss from "@tailwindcss/vite";
 import { defineConfig } from "vite";
 import tsconfigPaths from "vite-tsconfig-paths";
 
-export default defineConfig(({ isSsrBuild, command }) => ({
-  build: {
-    rollupOptions: isSsrBuild
-      ? {
-          input: "./server/app.ts",
-        }
-      : undefined,
-  },
+export default defineConfig(({ command }) => ({
   ssr: {
     noExternal: command === "build" ? true : undefined,
   },