From 0b8e4484126f79dc512a852f328c83d5329a44dc Mon Sep 17 00:00:00 2001
From: Richard Solomou <richard@solomou.io>
Date: Sat, 4 Oct 2025 08:38:49 +0300
Subject: [PATCH] fix immutable headers error

---
 src/react-start/index.ts | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/react-start/index.ts b/src/react-start/index.ts
index b55f3c1..94b7a2d 100644
--- a/src/react-start/index.ts
+++ b/src/react-start/index.ts
@@ -120,6 +120,15 @@ export const reactStartHandler = (
     throw new Error("VITE_CONVEX_SITE_URL is not set");
   }
   const nextUrl = `${convexSiteUrl}${requestUrl.pathname}${requestUrl.search}`;
-  request.headers.set("accept-encoding", "application/json");
-  return fetch(nextUrl, new Request(request, { redirect: "manual" }));
+
+  const headers = new Headers(request.headers);
+  headers.set("accept-encoding", "application/json");
+
+  return fetch(nextUrl, {
+    ...request,
+    headers,
+    redirect: "manual",
+    // @ts-ignore - duplex is required for streaming request bodies
+    duplex: 'half',
+  });
 };