nextjs-otel-node-middleware-parent/solution/gold.patch

diff --git a/packages/next/src/server/lib/trace/tracer.ts b/packages/next/src/server/lib/trace/tracer.ts
index 8866835fd7..c6289289fd 100644
--- a/packages/next/src/server/lib/trace/tracer.ts
+++ b/packages/next/src/server/lib/trace/tracer.ts
@@ -242,6 +242,19 @@ class NextTracerImpl implements NextTracer {
     return trace.getSpan(context?.active())
   }
 
+  /**
+   * Run `fn` with the active span cleared, so spans created inside become new
+   * roots (or parent to incoming propagated context). Used for in-process
+   * Node.js middleware so its span is a sibling of the request span, matching
+   * edge middleware which runs in a detached sandbox.
+   */
+  public runWithDetachedContext<T>(fn: () => T): T {
+    if (!NEXT_OTEL_PERFORMANCE_PREFIX && !this.isTracingEnabled()) {
+      return fn()
+    }
+    return context.with(ROOT_CONTEXT, fn)
+  }
+
   public withPropagatedContext<T, C>(
     carrier: C,
     fn: () => T,
diff --git a/packages/next/src/server/next-server.ts b/packages/next/src/server/next-server.ts
index 4b9eb7cb47..4ab6b5c088 100644
--- a/packages/next/src/server/next-server.ts
+++ b/packages/next/src/server/next-server.ts
@@ -1730,19 +1730,25 @@ export default class NextNodeServer extends BaseServer<
         Boolean(requestData.body)
 
       try {
-        result = await adapterFn({
-          handler:
-            middlewareModule.proxy ||
-            middlewareModule.middleware ||
-            middlewareModule,
-          request: {
-            ...requestData,
-            body: hasRequestBody
-              ? requestData.body.cloneBodyStream()
-              : undefined,
-          },
-          page: 'middleware',
-        })
+        // Node.js middleware runs in-process, inside the active
+        // `handleRequest` span. Detach that span so the middleware span
+        // becomes a sibling root (or parents to an incoming traceparent),
+        // matching edge middleware which runs in a detached sandbox.
+        result = await getTracer().runWithDetachedContext(() =>
+          adapterFn({
+            handler:
+              middlewareModule.proxy ||
+              middlewareModule.middleware ||
+              middlewareModule,
+            request: {
+              ...requestData,
+              body: hasRequestBody
+                ? requestData.body.cloneBodyStream()
+                : undefined,
+            },
+            page: 'middleware',
+          })
+        )
       } finally {
         if (hasRequestBody) {
           await requestData.body.finalize()