fix(nextjs): Bind wrapper isolation scope to pages-router API transaction

The wrapper forks a fresh isolation scope via withIsolationScope, but the
transaction is now the Next.js auto-instrumentation root span, which captured
a different scope. Request data, tags, and breadcrumbs set during the handler
were therefore lost from the transaction. Bind the wrapper's scope to the
active root span so they land on it again.

Author: logaretm

packages/nextjs/src/common/pages-router-instrumentation/wrapApiHandlerWithSentry.ts

@@ -1,4 +1,14 @@
-import { captureException, debug, httpRequestToRequestData, objectify, withIsolationScope } from '@sentry/core';
+import {
+  captureException,
+  debug,
+  getActiveSpan,
+  getCurrentScope,
+  getRootSpan,
+  httpRequestToRequestData,
+  objectify,
+  setCapturedScopesOnSpan,
+  withIsolationScope,
+} from '@sentry/core';
 import type { NextApiRequest } from 'next';
 import type { AugmentedNextApiResponse, NextApiHandler } from '../types';
 import { flushSafelyWithTimeout } from '../utils/responseEnd';
@@ -48,6 +58,15 @@ export function wrapApiHandlerWithSentry(apiHandler: NextApiHandler, parameteriz
         isolationScope.setSDKProcessingMetadata({ normalizedRequest: httpRequestToRequestData(req) });
         isolationScope.setTransactionName(`${reqMethod}${parameterizedRoute}`);
 
+        // We no longer create the transaction ourselves: it's the Next.js root span, which captured a different
+        // isolation scope than the one forked here. Bind this scope to that span so the request data and anything
+        // set on the scope during the handler (tags, breadcrumbs) land on the transaction.
+        const activeSpan = getActiveSpan();
+        const rootSpan = activeSpan ? getRootSpan(activeSpan) : undefined;
+        if (rootSpan) {
+          setCapturedScopesOnSpan(rootSpan, getCurrentScope(), isolationScope);
+        }
+
         try {
           return await wrappingTarget.apply(thisArg, args);
         } catch (e) {

packages/nextjs/src/edge/wrapApiHandlerWithSentry.ts

@@ -1,4 +1,12 @@
-import { captureException, winterCGRequestToRequestData, withIsolationScope } from '@sentry/core';
+import {
+  captureException,
+  getActiveSpan,
+  getCurrentScope,
+  getRootSpan,
+  setCapturedScopesOnSpan,
+  winterCGRequestToRequestData,
+  withIsolationScope,
+} from '@sentry/core';
 import { flushSafelyWithTimeout } from '../common/utils/responseEnd';
 import type { EdgeRouteHandler } from './types';
 
@@ -27,6 +35,15 @@ export function wrapApiHandlerWithSentry<H extends EdgeRouteHandler>(
           isolationScope.setTransactionName(`handler (${parameterizedRoute})`);
         }
 
+        // We no longer create the transaction ourselves: it's the Next.js `Node.runHandler` root span, which
+        // captured a different isolation scope than the one forked here. Bind this scope to that span so the
+        // request data and anything set on the scope during the handler (tags, breadcrumbs) land on the transaction.
+        const activeSpan = getActiveSpan();
+        const rootSpan = activeSpan ? getRootSpan(activeSpan) : undefined;
+        if (rootSpan) {
+          setCapturedScopesOnSpan(rootSpan, getCurrentScope(), isolationScope);
+        }
+
         try {
           return await wrappingTarget.apply(thisArg, args);
         } catch (error) {