diff --git a/api/discord/oauth/callback.ts b/api/discord/oauth/callback.ts
index 9bca3a5f..66634eb0 100644
--- a/api/discord/oauth/callback.ts
+++ b/api/discord/oauth/callback.ts
@@ -369,10 +369,21 @@ export default async function handler(req: any, res: any) {
           ? "/onboarding"
           : "/dashboard";
 
-    const redirectUrl = new URL(
-      nextPath,
-      process.env.VITE_API_BASE || "https://aethex.dev",
-    );
+    // Determine the base URL from environment or request origin
+    let baseUrl = process.env.VITE_API_BASE || process.env.API_BASE;
+
+    if (!baseUrl && req.headers.referer) {
+      // Extract base URL from referer header as fallback
+      const refererUrl = new URL(req.headers.referer);
+      baseUrl = refererUrl.origin;
+    }
+
+    // Final fallback - should not be needed if env vars are set
+    if (!baseUrl) {
+      baseUrl = "https://aethex.dev";
+    }
+
+    const redirectUrl = new URL(nextPath, baseUrl);
     res.redirect(redirectUrl.toString());
   } catch (error) {
     console.error("[Discord OAuth] Callback error:", error);