diff --git a/.env.example b/.env.example
new file mode 100644
index 0000000..76bd9ee
--- /dev/null
+++ b/.env.example
@@ -0,0 +1,4 @@
+# -----------------------------------------------------------------------------
+# App
+# -----------------------------------------------------------------------------
+NEXT_PUBLIC_APP_URL=http://localhost:3000
diff --git a/env.mjs b/env.mjs
new file mode 100644
index 0000000..4043621
--- /dev/null
+++ b/env.mjs
@@ -0,0 +1,15 @@
+import { createEnv } from "@t3-oss/env-nextjs";
+import { z } from "zod";
+
+export const env = createEnv({
+  server: {
+    // This is optional because it's only used in development.
+    // See https://next-auth.js.org/deployment.
+  },
+  client: {
+    NEXT_PUBLIC_APP_URL: z.string().min(1),
+  },
+  runtimeEnv: {
+    NEXT_PUBLIC_APP_URL: process.env.NEXT_PUBLIC_APP_URL,
+  },
+});