diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/constants.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/constants.ts
deleted file mode 100644
index ba3c35a08241..000000000000
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/constants.ts
+++ /dev/null
@@ -1,3 +0,0 @@
-// Corresponds to constants in featureFlags.ts, in browser utils.
-export const FLAG_BUFFER_SIZE = 100;
-export const MAX_FLAGS_PER_SPAN = 10;
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/featureFlags/onError/basic/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/featureFlags/onError/basic/test.ts
index 742cdd42109b..3233c9047649 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/featureFlags/onError/basic/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/featureFlags/onError/basic/test.ts
@@ -1,11 +1,11 @@
 import { expect } from '@playwright/test';
+import { _INTERNAL_FLAG_BUFFER_SIZE as FLAG_BUFFER_SIZE } from '@sentry/core';
 import { sentryTest } from '../../../../../../utils/fixtures';
 import {
   envelopeRequestParser,
   shouldSkipFeatureFlagsTest,
   waitForErrorRequest,
 } from '../../../../../../utils/helpers';
-import { FLAG_BUFFER_SIZE } from '../../../constants';
 
 sentryTest('Basic test with eviction, update, and no async tasks', async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest()) {
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/featureFlags/onSpan/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/featureFlags/onSpan/test.ts
index 476b76d03475..6516d8e36abb 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/featureFlags/onSpan/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/featureFlags/onSpan/test.ts
@@ -1,4 +1,5 @@
 import { expect } from '@playwright/test';
+import { _INTERNAL_MAX_FLAGS_PER_SPAN as MAX_FLAGS_PER_SPAN } from '@sentry/core';
 import { sentryTest } from '../../../../../utils/fixtures';
 import {
   type EventAndTraceHeader,
@@ -7,7 +8,6 @@ import {
   shouldSkipFeatureFlagsTest,
   shouldSkipTracingTest,
 } from '../../../../../utils/helpers';
-import { MAX_FLAGS_PER_SPAN } from '../../constants';
 
 sentryTest("Feature flags are added to active span's attributes on span end.", async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest() || shouldSkipTracingTest()) {
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/launchdarkly/onError/basic/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/launchdarkly/onError/basic/test.ts
index 1c1a04595187..bc3e0afdc292 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/launchdarkly/onError/basic/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/launchdarkly/onError/basic/test.ts
@@ -1,11 +1,11 @@
 import { expect } from '@playwright/test';
+import { _INTERNAL_FLAG_BUFFER_SIZE as FLAG_BUFFER_SIZE } from '@sentry/core';
 import { sentryTest } from '../../../../../../utils/fixtures';
 import {
   envelopeRequestParser,
   shouldSkipFeatureFlagsTest,
   waitForErrorRequest,
 } from '../../../../../../utils/helpers';
-import { FLAG_BUFFER_SIZE } from '../../../constants';
 
 sentryTest('Basic test with eviction, update, and no async tasks', async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest()) {
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/launchdarkly/onSpan/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/launchdarkly/onSpan/test.ts
index 965f00f91fa0..eb7eb003c838 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/launchdarkly/onSpan/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/launchdarkly/onSpan/test.ts
@@ -1,4 +1,5 @@
 import { expect } from '@playwright/test';
+import { _INTERNAL_MAX_FLAGS_PER_SPAN as MAX_FLAGS_PER_SPAN } from '@sentry/core';
 import { sentryTest } from '../../../../../utils/fixtures';
 import {
   type EventAndTraceHeader,
@@ -7,7 +8,6 @@ import {
   shouldSkipFeatureFlagsTest,
   shouldSkipTracingTest,
 } from '../../../../../utils/helpers';
-import { MAX_FLAGS_PER_SPAN } from '../../constants';
 
 sentryTest("Feature flags are added to active span's attributes on span end.", async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest() || shouldSkipTracingTest()) {
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/onError/basic/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/onError/basic/test.ts
index 84deca47415d..5953f1e0b087 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/onError/basic/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/onError/basic/test.ts
@@ -1,11 +1,11 @@
 import { expect } from '@playwright/test';
+import { _INTERNAL_FLAG_BUFFER_SIZE as FLAG_BUFFER_SIZE } from '@sentry/core';
 import { sentryTest } from '../../../../../../utils/fixtures';
 import {
   envelopeRequestParser,
   shouldSkipFeatureFlagsTest,
   waitForErrorRequest,
 } from '../../../../../../utils/helpers';
-import { FLAG_BUFFER_SIZE } from '../../../constants';
 
 sentryTest('Basic test with eviction, update, and no async tasks', async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest()) {
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/onError/errorHook/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/onError/errorHook/test.ts
index c2de7f54abd7..89654c82eda1 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/onError/errorHook/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/onError/errorHook/test.ts
@@ -1,11 +1,11 @@
 import { expect } from '@playwright/test';
+import { _INTERNAL_FLAG_BUFFER_SIZE as FLAG_BUFFER_SIZE } from '@sentry/core';
 import { sentryTest } from '../../../../../../utils/fixtures';
 import {
   envelopeRequestParser,
   shouldSkipFeatureFlagsTest,
   waitForErrorRequest,
 } from '../../../../../../utils/helpers';
-import { FLAG_BUFFER_SIZE } from '../../../constants';
 
 sentryTest('Flag evaluation error hook', async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest()) {
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/onSpan/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/onSpan/test.ts
index f3b43425477f..5ade5d01b3d5 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/onSpan/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/openfeature/onSpan/test.ts
@@ -1,4 +1,5 @@
 import { expect } from '@playwright/test';
+import { _INTERNAL_MAX_FLAGS_PER_SPAN as MAX_FLAGS_PER_SPAN } from '@sentry/core';
 import { sentryTest } from '../../../../../utils/fixtures';
 import {
   type EventAndTraceHeader,
@@ -7,7 +8,6 @@ import {
   shouldSkipFeatureFlagsTest,
   shouldSkipTracingTest,
 } from '../../../../../utils/helpers';
-import { MAX_FLAGS_PER_SPAN } from '../../constants';
 
 sentryTest("Feature flags are added to active span's attributes on span end.", async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest() || shouldSkipTracingTest()) {
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/onError/basic/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/onError/basic/test.ts
index 331dbb8ad433..134b29417d53 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/onError/basic/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/onError/basic/test.ts
@@ -1,11 +1,11 @@
 import { expect } from '@playwright/test';
+import { _INTERNAL_FLAG_BUFFER_SIZE as FLAG_BUFFER_SIZE } from '@sentry/core';
 import { sentryTest } from '../../../../../../utils/fixtures';
 import {
   envelopeRequestParser,
   shouldSkipFeatureFlagsTest,
   waitForErrorRequest,
 } from '../../../../../../utils/helpers';
-import { FLAG_BUFFER_SIZE } from '../../../constants';
 
 sentryTest('Basic test with eviction, update, and no async tasks', async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest()) {
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/onSpan/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/onSpan/test.ts
index dec534f9ffab..1ea192f98850 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/onSpan/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/statsig/onSpan/test.ts
@@ -1,4 +1,5 @@
 import { expect } from '@playwright/test';
+import { _INTERNAL_MAX_FLAGS_PER_SPAN as MAX_FLAGS_PER_SPAN } from '@sentry/core';
 import { sentryTest } from '../../../../../utils/fixtures';
 import {
   type EventAndTraceHeader,
@@ -7,7 +8,6 @@ import {
   shouldSkipFeatureFlagsTest,
   shouldSkipTracingTest,
 } from '../../../../../utils/helpers';
-import { MAX_FLAGS_PER_SPAN } from '../../constants';
 
 sentryTest("Feature flags are added to active span's attributes on span end.", async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest() || shouldSkipTracingTest()) {
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/onError/basic/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/onError/basic/test.ts
index 341bbbd03e96..6e2760b69600 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/onError/basic/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/onError/basic/test.ts
@@ -1,11 +1,11 @@
 import { expect } from '@playwright/test';
+import { _INTERNAL_FLAG_BUFFER_SIZE as FLAG_BUFFER_SIZE } from '@sentry/core';
 import { sentryTest } from '../../../../../../utils/fixtures';
 import {
   envelopeRequestParser,
   shouldSkipFeatureFlagsTest,
   waitForErrorRequest,
 } from '../../../../../../utils/helpers';
-import { FLAG_BUFFER_SIZE } from '../../../constants';
 
 sentryTest('Basic test with eviction, update, and no async tasks', async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest()) {
diff --git a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/onSpan/test.ts b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/onSpan/test.ts
index b2607ffa4c07..984bba3bc0e3 100644
--- a/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/onSpan/test.ts
+++ b/dev-packages/browser-integration-tests/suites/integrations/featureFlags/unleash/onSpan/test.ts
@@ -1,4 +1,5 @@
 import { expect } from '@playwright/test';
+import { _INTERNAL_MAX_FLAGS_PER_SPAN as MAX_FLAGS_PER_SPAN } from '@sentry/core';
 import { sentryTest } from '../../../../../utils/fixtures';
 import {
   type EventAndTraceHeader,
@@ -7,7 +8,6 @@ import {
   shouldSkipFeatureFlagsTest,
   shouldSkipTracingTest,
 } from '../../../../../utils/helpers';
-import { MAX_FLAGS_PER_SPAN } from '../../constants';
 
 sentryTest("Feature flags are added to active span's attributes on span end.", async ({ getLocalTestUrl, page }) => {
   if (shouldSkipFeatureFlagsTest() || shouldSkipTracingTest()) {
diff --git a/dev-packages/node-integration-tests/suites/featureFlags/featureFlagsIntegration/onError/basic/scenario.ts b/dev-packages/node-integration-tests/suites/featureFlags/featureFlagsIntegration/onError/basic/scenario.ts
new file mode 100644
index 000000000000..6d1b88137b87
--- /dev/null
+++ b/dev-packages/node-integration-tests/suites/featureFlags/featureFlagsIntegration/onError/basic/scenario.ts
@@ -0,0 +1,19 @@
+import { _INTERNAL_FLAG_BUFFER_SIZE as FLAG_BUFFER_SIZE } from '@sentry/core';
+import * as Sentry from '@sentry/node';
+import { loggingTransport } from '@sentry-internal/node-integration-tests';
+
+Sentry.init({
+  dsn: 'https://public@dsn.ingest.sentry.io/1337',
+  sampleRate: 1.0,
+  transport: loggingTransport,
+  integrations: [Sentry.featureFlagsIntegration()],
+});
+
+const flagsIntegration = Sentry.getClient()?.getIntegrationByName<Sentry.FeatureFlagsIntegration>('FeatureFlags');
+for (let i = 1; i <= FLAG_BUFFER_SIZE; i++) {
+  flagsIntegration?.addFeatureFlag(`feat${i}`, false);
+}
+flagsIntegration?.addFeatureFlag(`feat${FLAG_BUFFER_SIZE + 1}`, true); // eviction
+flagsIntegration?.addFeatureFlag('feat3', true); // update
+
+throw new Error('Test error');
diff --git a/dev-packages/node-integration-tests/suites/featureFlags/featureFlagsIntegration/onError/basic/test.ts b/dev-packages/node-integration-tests/suites/featureFlags/featureFlagsIntegration/onError/basic/test.ts
new file mode 100644
index 000000000000..74ff1c125b45
--- /dev/null
+++ b/dev-packages/node-integration-tests/suites/featureFlags/featureFlagsIntegration/onError/basic/test.ts
@@ -0,0 +1,31 @@
+import { _INTERNAL_FLAG_BUFFER_SIZE as FLAG_BUFFER_SIZE } from '@sentry/core';
+import { afterAll, test } from 'vitest';
+import { cleanupChildProcesses, createRunner } from '../../../../../utils/runner';
+
+afterAll(() => {
+  cleanupChildProcesses();
+});
+
+test('Flags captured on error with eviction, update, and no async tasks', async () => {
+  // Based on scenario.ts.
+  const expectedFlags = [{ flag: 'feat2', result: false }];
+  for (let i = 4; i <= FLAG_BUFFER_SIZE; i++) {
+    expectedFlags.push({ flag: `feat${i}`, result: false });
+  }
+  expectedFlags.push({ flag: `feat${FLAG_BUFFER_SIZE + 1}`, result: true });
+  expectedFlags.push({ flag: 'feat3', result: true });
+
+  await createRunner(__dirname, 'scenario.ts')
+    .expect({
+      event: {
+        exception: { values: [{ type: 'Error', value: 'Test error' }] },
+        contexts: {
+          flags: {
+            values: expectedFlags,
+          },
+        },
+      },
+    })
+    .start()
+    .completed();
+});
diff --git a/dev-packages/node-integration-tests/suites/featureFlags/featureFlagsIntegration/onError/withScope/scenario.ts b/dev-packages/node-integration-tests/suites/featureFlags/featureFlagsIntegration/onError/withScope/scenario.ts
new file mode 100644
index 000000000000..b6537011a87f
--- /dev/null
+++ b/dev-packages/node-integration-tests/suites/featureFlags/featureFlagsIntegration/onError/withScope/scenario.ts
@@ -0,0 +1,22 @@
+import type { Scope } from '@sentry/node';
+import * as Sentry from '@sentry/node';
+import { loggingTransport } from '@sentry-internal/node-integration-tests';
+
+Sentry.init({
+  dsn: 'https://public@dsn.ingest.sentry.io/1337',
+  sampleRate: 1.0,
+  transport: loggingTransport,
+  integrations: [Sentry.featureFlagsIntegration()],
+});
+
+const flagsIntegration = Sentry.getClient()?.getIntegrationByName<Sentry.FeatureFlagsIntegration>('FeatureFlags');
+flagsIntegration?.addFeatureFlag('shared', true);
+
+Sentry.withScope((_scope: Scope) => {
+  flagsIntegration?.addFeatureFlag('forked', true);
+  flagsIntegration?.addFeatureFlag('shared', false);
+  Sentry.captureException(new Error('Error in forked scope'));
+});
+
+flagsIntegration?.addFeatureFlag('main', true);
+throw new Error('Error in main scope');
diff --git a/dev-packages/node-integration-tests/suites/featureFlags/featureFlagsIntegration/onError/withScope/test.ts b/dev-packages/node-integration-tests/suites/featureFlags/featureFlagsIntegration/onError/withScope/test.ts
new file mode 100644
index 000000000000..947b299923e7
--- /dev/null
+++ b/dev-packages/node-integration-tests/suites/featureFlags/featureFlagsIntegration/onError/withScope/test.ts
@@ -0,0 +1,38 @@
+import { afterAll, test } from 'vitest';
+import { cleanupChildProcesses, createRunner } from '../../../../../utils/runner';
+
+afterAll(() => {
+  cleanupChildProcesses();
+});
+
+test('Flags captured on error are isolated by current scope', async () => {
+  await createRunner(__dirname, 'scenario.ts')
+    .expect({
+      event: {
+        exception: { values: [{ type: 'Error', value: 'Error in forked scope' }] },
+        contexts: {
+          flags: {
+            values: [
+              { flag: 'forked', result: true },
+              { flag: 'shared', result: false },
+            ],
+          },
+        },
+      },
+    })
+    .expect({
+      event: {
+        exception: { values: [{ type: 'Error', value: 'Error in main scope' }] },
+        contexts: {
+          flags: {
+            values: [
+              { flag: 'shared', result: true },
+              { flag: 'main', result: true },
+            ],
+          },
+        },
+      },
+    })
+    .start()
+    .completed();
+});
diff --git a/dev-packages/node-integration-tests/suites/featureFlags/featureFlagsIntegration/onSpan/scenario.ts b/dev-packages/node-integration-tests/suites/featureFlags/featureFlagsIntegration/onSpan/scenario.ts
new file mode 100644
index 000000000000..2c07e46b40ed
--- /dev/null
+++ b/dev-packages/node-integration-tests/suites/featureFlags/featureFlagsIntegration/onSpan/scenario.ts
@@ -0,0 +1,25 @@
+import { _INTERNAL_MAX_FLAGS_PER_SPAN as MAX_FLAGS_PER_SPAN } from '@sentry/core';
+import * as Sentry from '@sentry/node';
+import { loggingTransport } from '@sentry-internal/node-integration-tests';
+
+Sentry.init({
+  dsn: 'https://public@dsn.ingest.sentry.io/1337',
+  sampleRate: 1.0,
+  tracesSampleRate: 1.0,
+  transport: loggingTransport,
+  integrations: [Sentry.featureFlagsIntegration()],
+});
+
+const flagsIntegration = Sentry.getClient()?.getIntegrationByName<Sentry.FeatureFlagsIntegration>('FeatureFlags');
+
+Sentry.startSpan({ name: 'test-root-span' }, () => {
+  Sentry.startSpan({ name: 'test-span' }, () => {
+    Sentry.startSpan({ name: 'test-nested-span' }, () => {
+      for (let i = 1; i <= MAX_FLAGS_PER_SPAN; i++) {
+        flagsIntegration?.addFeatureFlag(`feat${i}`, false);
+      }
+      flagsIntegration?.addFeatureFlag(`feat${MAX_FLAGS_PER_SPAN + 1}`, true); // dropped flag
+      flagsIntegration?.addFeatureFlag('feat3', true); // update
+    });
+  });
+});
diff --git a/dev-packages/node-integration-tests/suites/featureFlags/featureFlagsIntegration/onSpan/test.ts b/dev-packages/node-integration-tests/suites/featureFlags/featureFlagsIntegration/onSpan/test.ts
new file mode 100644
index 000000000000..4a417a3c3959
--- /dev/null
+++ b/dev-packages/node-integration-tests/suites/featureFlags/featureFlagsIntegration/onSpan/test.ts
@@ -0,0 +1,33 @@
+import { _INTERNAL_MAX_FLAGS_PER_SPAN as MAX_FLAGS_PER_SPAN } from '@sentry/core';
+import { afterAll, expect, test } from 'vitest';
+import { cleanupChildProcesses, createRunner } from '../../../../utils/runner';
+
+afterAll(() => {
+  cleanupChildProcesses();
+});
+
+test('Flags captured on span attributes with max limit', async () => {
+  // Based on scenario.ts.
+  const expectedFlags: Record<string, boolean> = {};
+  for (let i = 1; i <= MAX_FLAGS_PER_SPAN; i++) {
+    expectedFlags[`flag.evaluation.feat${i}`] = i === 3;
+  }
+
+  await createRunner(__dirname, 'scenario.ts')
+    .expect({
+      transaction: {
+        spans: [
+          expect.objectContaining({
+            description: 'test-span',
+            data: expect.objectContaining({}),
+          }),
+          expect.objectContaining({
+            description: 'test-nested-span',
+            data: expect.objectContaining(expectedFlags),
+          }),
+        ],
+      },
+    })
+    .start()
+    .completed();
+});
diff --git a/packages/astro/src/index.server.ts b/packages/astro/src/index.server.ts
index ac222eca825b..750eb05d8b10 100644
--- a/packages/astro/src/index.server.ts
+++ b/packages/astro/src/index.server.ts
@@ -135,6 +135,8 @@ export {
   consoleLoggingIntegration,
   wrapMcpServerWithSentry,
   NODE_VERSION,
+  featureFlagsIntegration,
+  type FeatureFlagsIntegration,
 } from '@sentry/node';
 
 export { init } from './server/sdk';
diff --git a/packages/aws-serverless/src/index.ts b/packages/aws-serverless/src/index.ts
index 24513a325188..b13f69a9b6ce 100644
--- a/packages/aws-serverless/src/index.ts
+++ b/packages/aws-serverless/src/index.ts
@@ -121,6 +121,8 @@ export {
   consoleLoggingIntegration,
   wrapMcpServerWithSentry,
   NODE_VERSION,
+  featureFlagsIntegration,
+  type FeatureFlagsIntegration,
 } from '@sentry/node';
 
 export {
diff --git a/packages/browser/src/index.ts b/packages/browser/src/index.ts
index 2b2279c099b3..963d8ab38546 100644
--- a/packages/browser/src/index.ts
+++ b/packages/browser/src/index.ts
@@ -61,13 +61,13 @@ export {
   instrumentSupabaseClient,
   zodErrorsIntegration,
   thirdPartyErrorFilterIntegration,
+  featureFlagsIntegration,
 } from '@sentry/core';
-export type { Span } from '@sentry/core';
+export type { Span, FeatureFlagsIntegration } from '@sentry/core';
 export { makeBrowserOfflineTransport } from './transports/offline';
 export { browserProfilingIntegration } from './profiling/integration';
 export { spotlightBrowserIntegration } from './integrations/spotlight';
 export { browserSessionIntegration } from './integrations/browsersession';
-export { featureFlagsIntegration, type FeatureFlagsIntegration } from './integrations/featureFlags';
 export { launchDarklyIntegration, buildLaunchDarklyFlagUsedHandler } from './integrations/featureFlags/launchdarkly';
 export { openFeatureIntegration, OpenFeatureIntegrationHook } from './integrations/featureFlags/openfeature';
 export { unleashIntegration } from './integrations/featureFlags/unleash';
diff --git a/packages/browser/src/integrations/featureFlags/launchdarkly/integration.ts b/packages/browser/src/integrations/featureFlags/launchdarkly/integration.ts
index eeb20dc07cf9..822e4b1d7f80 100644
--- a/packages/browser/src/integrations/featureFlags/launchdarkly/integration.ts
+++ b/packages/browser/src/integrations/featureFlags/launchdarkly/integration.ts
@@ -1,6 +1,10 @@
 import type { Client, Event, EventHint, IntegrationFn } from '@sentry/core';
-import { defineIntegration } from '@sentry/core';
-import { addFeatureFlagToActiveSpan, copyFlagsFromScopeToEvent, insertFlagToScope } from '../../../utils/featureFlags';
+import {
+  _INTERNAL_addFeatureFlagToActiveSpan,
+  _INTERNAL_copyFlagsFromScopeToEvent,
+  _INTERNAL_insertFlagToScope,
+  defineIntegration,
+} from '@sentry/core';
 import type { LDContext, LDEvaluationDetail, LDInspectionFlagUsedHandler } from './types';
 
 /**
@@ -23,7 +27,7 @@ export const launchDarklyIntegration = defineIntegration(() => {
     name: 'LaunchDarkly',
 
     processEvent(event: Event, _hint: EventHint, _client: Client): Event {
-      return copyFlagsFromScopeToEvent(event);
+      return _INTERNAL_copyFlagsFromScopeToEvent(event);
     },
   };
 }) satisfies IntegrationFn;
@@ -45,8 +49,8 @@ export function buildLaunchDarklyFlagUsedHandler(): LDInspectionFlagUsedHandler
      * Handle a flag evaluation by storing its name and value on the current scope.
      */
     method: (flagKey: string, flagDetail: LDEvaluationDetail, _context: LDContext) => {
-      insertFlagToScope(flagKey, flagDetail.value);
-      addFeatureFlagToActiveSpan(flagKey, flagDetail.value);
+      _INTERNAL_insertFlagToScope(flagKey, flagDetail.value);
+      _INTERNAL_addFeatureFlagToActiveSpan(flagKey, flagDetail.value);
     },
   };
 }
diff --git a/packages/browser/src/integrations/featureFlags/openfeature/integration.ts b/packages/browser/src/integrations/featureFlags/openfeature/integration.ts
index 79dc97394cce..85aedbf779f9 100644
--- a/packages/browser/src/integrations/featureFlags/openfeature/integration.ts
+++ b/packages/browser/src/integrations/featureFlags/openfeature/integration.ts
@@ -14,8 +14,12 @@
  * ```
  */
 import type { Client, Event, EventHint, IntegrationFn } from '@sentry/core';
-import { defineIntegration } from '@sentry/core';
-import { addFeatureFlagToActiveSpan, copyFlagsFromScopeToEvent, insertFlagToScope } from '../../../utils/featureFlags';
+import {
+  _INTERNAL_addFeatureFlagToActiveSpan,
+  _INTERNAL_copyFlagsFromScopeToEvent,
+  _INTERNAL_insertFlagToScope,
+  defineIntegration,
+} from '@sentry/core';
 import type { EvaluationDetails, HookContext, HookHints, JsonValue, OpenFeatureHook } from './types';
 
 export const openFeatureIntegration = defineIntegration(() => {
@@ -23,7 +27,7 @@ export const openFeatureIntegration = defineIntegration(() => {
     name: 'OpenFeature',
 
     processEvent(event: Event, _hint: EventHint, _client: Client): Event {
-      return copyFlagsFromScopeToEvent(event);
+      return _INTERNAL_copyFlagsFromScopeToEvent(event);
     },
   };
 }) satisfies IntegrationFn;
@@ -36,15 +40,15 @@ export class OpenFeatureIntegrationHook implements OpenFeatureHook {
    * Successful evaluation result.
    */
   public after(_hookContext: Readonly<HookContext<JsonValue>>, evaluationDetails: EvaluationDetails<JsonValue>): void {
-    insertFlagToScope(evaluationDetails.flagKey, evaluationDetails.value);
-    addFeatureFlagToActiveSpan(evaluationDetails.flagKey, evaluationDetails.value);
+    _INTERNAL_insertFlagToScope(evaluationDetails.flagKey, evaluationDetails.value);
+    _INTERNAL_addFeatureFlagToActiveSpan(evaluationDetails.flagKey, evaluationDetails.value);
   }
 
   /**
    * On error evaluation result.
    */
   public error(hookContext: Readonly<HookContext<JsonValue>>, _error: unknown, _hookHints?: HookHints): void {
-    insertFlagToScope(hookContext.flagKey, hookContext.defaultValue);
-    addFeatureFlagToActiveSpan(hookContext.flagKey, hookContext.defaultValue);
+    _INTERNAL_insertFlagToScope(hookContext.flagKey, hookContext.defaultValue);
+    _INTERNAL_addFeatureFlagToActiveSpan(hookContext.flagKey, hookContext.defaultValue);
   }
 }
diff --git a/packages/browser/src/integrations/featureFlags/statsig/integration.ts b/packages/browser/src/integrations/featureFlags/statsig/integration.ts
index ee472d77669a..9aef234045b5 100644
--- a/packages/browser/src/integrations/featureFlags/statsig/integration.ts
+++ b/packages/browser/src/integrations/featureFlags/statsig/integration.ts
@@ -1,6 +1,10 @@
 import type { Client, Event, EventHint, IntegrationFn } from '@sentry/core';
-import { defineIntegration } from '@sentry/core';
-import { addFeatureFlagToActiveSpan, copyFlagsFromScopeToEvent, insertFlagToScope } from '../../../utils/featureFlags';
+import {
+  _INTERNAL_addFeatureFlagToActiveSpan,
+  _INTERNAL_copyFlagsFromScopeToEvent,
+  _INTERNAL_insertFlagToScope,
+  defineIntegration,
+} from '@sentry/core';
 import type { FeatureGate, StatsigClient } from './types';
 
 /**
@@ -33,13 +37,13 @@ export const statsigIntegration = defineIntegration(
 
       setup(_client: Client) {
         statsigClient.on('gate_evaluation', (event: { gate: FeatureGate }) => {
-          insertFlagToScope(event.gate.name, event.gate.value);
-          addFeatureFlagToActiveSpan(event.gate.name, event.gate.value);
+          _INTERNAL_insertFlagToScope(event.gate.name, event.gate.value);
+          _INTERNAL_addFeatureFlagToActiveSpan(event.gate.name, event.gate.value);
         });
       },
 
       processEvent(event: Event, _hint: EventHint, _client: Client): Event {
-        return copyFlagsFromScopeToEvent(event);
+        return _INTERNAL_copyFlagsFromScopeToEvent(event);
       },
     };
   },
diff --git a/packages/browser/src/integrations/featureFlags/unleash/integration.ts b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
index ee7e2a3a0d4d..699c797edecf 100644
--- a/packages/browser/src/integrations/featureFlags/unleash/integration.ts
+++ b/packages/browser/src/integrations/featureFlags/unleash/integration.ts
@@ -1,7 +1,13 @@
 import type { Client, Event, EventHint, IntegrationFn } from '@sentry/core';
-import { defineIntegration, fill, logger } from '@sentry/core';
+import {
+  _INTERNAL_addFeatureFlagToActiveSpan,
+  _INTERNAL_copyFlagsFromScopeToEvent,
+  _INTERNAL_insertFlagToScope,
+  defineIntegration,
+  fill,
+  logger,
+} from '@sentry/core';
 import { DEBUG_BUILD } from '../../../debug-build';
-import { addFeatureFlagToActiveSpan, copyFlagsFromScopeToEvent, insertFlagToScope } from '../../../utils/featureFlags';
 import type { UnleashClient, UnleashClientClass } from './types';
 
 type UnleashIntegrationOptions = {
@@ -41,7 +47,7 @@ export const unleashIntegration = defineIntegration(
       },
 
       processEvent(event: Event, _hint: EventHint, _client: Client): Event {
-        return copyFlagsFromScopeToEvent(event);
+        return _INTERNAL_copyFlagsFromScopeToEvent(event);
       },
     };
   },
@@ -64,8 +70,8 @@ function _wrappedIsEnabled(
     const result = original.apply(this, args);
 
     if (typeof toggleName === 'string' && typeof result === 'boolean') {
-      insertFlagToScope(toggleName, result);
-      addFeatureFlagToActiveSpan(toggleName, result);
+      _INTERNAL_insertFlagToScope(toggleName, result);
+      _INTERNAL_addFeatureFlagToActiveSpan(toggleName, result);
     } else if (DEBUG_BUILD) {
       logger.error(
         `[Feature Flags] UnleashClient.isEnabled does not match expected signature. arg0: ${toggleName} (${typeof toggleName}), result: ${result} (${typeof result})`,
diff --git a/packages/bun/src/index.ts b/packages/bun/src/index.ts
index 70104de6d7c3..14a44e2d38fc 100644
--- a/packages/bun/src/index.ts
+++ b/packages/bun/src/index.ts
@@ -15,6 +15,7 @@ export type {
   Stacktrace,
   Thread,
   User,
+  FeatureFlagsIntegration,
 } from '@sentry/core';
 
 export {
@@ -139,6 +140,7 @@ export {
   consoleLoggingIntegration,
   createSentryWinstonTransport,
   wrapMcpServerWithSentry,
+  featureFlagsIntegration,
 } from '@sentry/node';
 
 export {
diff --git a/packages/cloudflare/src/index.ts b/packages/cloudflare/src/index.ts
index 6754ffd04f7c..1a366aeb5dd0 100644
--- a/packages/cloudflare/src/index.ts
+++ b/packages/cloudflare/src/index.ts
@@ -8,6 +8,7 @@ export type {
   EventHint,
   ErrorEvent,
   Exception,
+  FeatureFlagsIntegration,
   Session,
   SeverityLevel,
   Span,
@@ -91,6 +92,7 @@ export {
   updateSpanName,
   wrapMcpServerWithSentry,
   consoleLoggingIntegration,
+  featureFlagsIntegration,
 } from '@sentry/core';
 
 export * as logger from './logs/exports';
diff --git a/packages/core/src/featureFlags.ts b/packages/core/src/featureFlags.ts
deleted file mode 100644
index f80e17ef7f9d..000000000000
--- a/packages/core/src/featureFlags.ts
+++ /dev/null
@@ -1 +0,0 @@
-export type FeatureFlag = { readonly flag: string; readonly result: boolean };
diff --git a/packages/core/src/index.ts b/packages/core/src/index.ts
index d418b8a28c19..fdbcd8bffbef 100644
--- a/packages/core/src/index.ts
+++ b/packages/core/src/index.ts
@@ -113,6 +113,7 @@ export { supabaseIntegration, instrumentSupabaseClient } from './integrations/su
 export { zodErrorsIntegration } from './integrations/zoderrors';
 export { thirdPartyErrorFilterIntegration } from './integrations/third-party-errors-filter';
 export { consoleIntegration } from './integrations/console';
+export { featureFlagsIntegration, type FeatureFlagsIntegration } from './integrations/featureFlags';
 
 export { profiler } from './profiling';
 export { instrumentFetchRequest } from './fetch';
@@ -123,7 +124,14 @@ export type { ReportDialogOptions } from './report-dialog';
 export { _INTERNAL_captureLog, _INTERNAL_flushLogsBuffer, _INTERNAL_captureSerializedLog } from './logs/exports';
 export { consoleLoggingIntegration } from './logs/console-integration';
 
-export type { FeatureFlag } from './featureFlags';
+export type { FeatureFlag } from './utils/featureFlags';
+export {
+  _INTERNAL_copyFlagsFromScopeToEvent,
+  _INTERNAL_insertFlagToScope,
+  _INTERNAL_addFeatureFlagToActiveSpan,
+  _INTERNAL_FLAG_BUFFER_SIZE,
+  _INTERNAL_MAX_FLAGS_PER_SPAN,
+} from './utils/featureFlags';
 
 export { applyAggregateErrorsToEvent } from './utils-hoist/aggregate-errors';
 export { getBreadcrumbLogLevelFromHttpStatusCode } from './utils-hoist/breadcrumb-log-level';
diff --git a/packages/browser/src/integrations/featureFlags/featureFlagsIntegration.ts b/packages/core/src/integrations/featureFlags/featureFlagsIntegration.ts
similarity index 69%
rename from packages/browser/src/integrations/featureFlags/featureFlagsIntegration.ts
rename to packages/core/src/integrations/featureFlags/featureFlagsIntegration.ts
index e11084c84c2d..fddc1944ceab 100644
--- a/packages/browser/src/integrations/featureFlags/featureFlagsIntegration.ts
+++ b/packages/core/src/integrations/featureFlags/featureFlagsIntegration.ts
@@ -1,6 +1,12 @@
-import type { Client, Event, EventHint, Integration, IntegrationFn } from '@sentry/core';
-import { defineIntegration } from '@sentry/core';
-import { addFeatureFlagToActiveSpan, copyFlagsFromScopeToEvent, insertFlagToScope } from '../../utils/featureFlags';
+import { type Client } from '../../client';
+import { defineIntegration } from '../../integration';
+import { type Event, type EventHint } from '../../types-hoist/event';
+import { type Integration, type IntegrationFn } from '../../types-hoist/integration';
+import {
+  _INTERNAL_addFeatureFlagToActiveSpan,
+  _INTERNAL_copyFlagsFromScopeToEvent,
+  _INTERNAL_insertFlagToScope,
+} from '../../utils/featureFlags';
 
 export interface FeatureFlagsIntegration extends Integration {
   addFeatureFlag: (name: string, value: unknown) => void;
@@ -35,12 +41,12 @@ export const featureFlagsIntegration = defineIntegration(() => {
     name: 'FeatureFlags',
 
     processEvent(event: Event, _hint: EventHint, _client: Client): Event {
-      return copyFlagsFromScopeToEvent(event);
+      return _INTERNAL_copyFlagsFromScopeToEvent(event);
     },
 
     addFeatureFlag(name: string, value: unknown): void {
-      insertFlagToScope(name, value);
-      addFeatureFlagToActiveSpan(name, value);
+      _INTERNAL_insertFlagToScope(name, value);
+      _INTERNAL_addFeatureFlagToActiveSpan(name, value);
     },
   };
 }) as IntegrationFn<FeatureFlagsIntegration>;
diff --git a/packages/browser/src/integrations/featureFlags/index.ts b/packages/core/src/integrations/featureFlags/index.ts
similarity index 100%
rename from packages/browser/src/integrations/featureFlags/index.ts
rename to packages/core/src/integrations/featureFlags/index.ts
diff --git a/packages/core/src/types-hoist/context.ts b/packages/core/src/types-hoist/context.ts
index 0ad6eebf6ac3..a3673f84a968 100644
--- a/packages/core/src/types-hoist/context.ts
+++ b/packages/core/src/types-hoist/context.ts
@@ -1,4 +1,4 @@
-import type { FeatureFlag } from '../featureFlags';
+import type { FeatureFlag } from '../utils/featureFlags';
 import type { SpanLinkJSON } from './link';
 import type { Primitive } from './misc';
 import type { SpanOrigin } from './span';
diff --git a/packages/browser/src/utils/featureFlags.ts b/packages/core/src/utils/featureFlags.ts
similarity index 80%
rename from packages/browser/src/utils/featureFlags.ts
rename to packages/core/src/utils/featureFlags.ts
index 9ae389773bcd..388613394148 100644
--- a/packages/browser/src/utils/featureFlags.ts
+++ b/packages/core/src/utils/featureFlags.ts
@@ -1,6 +1,10 @@
-import type { Event, FeatureFlag, Span } from '@sentry/core';
-import { getActiveSpan, getCurrentScope, GLOBAL_OBJ, logger } from '@sentry/core';
+import { getCurrentScope } from '../currentScopes';
 import { DEBUG_BUILD } from '../debug-build';
+import { type Event } from '../types-hoist/event';
+import { type Span } from '../types-hoist/span';
+import { logger } from '../utils-hoist/logger';
+import { GLOBAL_OBJ } from '../utils-hoist/worldwide';
+import { getActiveSpan } from './spanUtils';
 
 /**
  * Ordered LRU cache for storing feature flags in the scope context. The name
@@ -8,15 +12,17 @@ import { DEBUG_BUILD } from '../debug-build';
  * from oldest to newest.
  */
 
+export type FeatureFlag = { readonly flag: string; readonly result: boolean };
+
 /**
  * Max size of the LRU flag buffer stored in Sentry scope and event contexts.
  */
-export const FLAG_BUFFER_SIZE = 100;
+export const _INTERNAL_FLAG_BUFFER_SIZE = 100;
 
 /**
  * Max number of flag evaluations to record per span.
  */
-export const MAX_FLAGS_PER_SPAN = 10;
+export const _INTERNAL_MAX_FLAGS_PER_SPAN = 10;
 
 // Global map of spans to feature flag buffers. Populated by feature flag integrations.
 GLOBAL_OBJ._spanToFlagBufferMap = new WeakMap<Span, Set<string>>();
@@ -26,7 +32,7 @@ const SPAN_FLAG_ATTRIBUTE_PREFIX = 'flag.evaluation.';
 /**
  * Copies feature flags that are in current scope context to the event context
  */
-export function copyFlagsFromScopeToEvent(event: Event): Event {
+export function _INTERNAL_copyFlagsFromScopeToEvent(event: Event): Event {
   const scope = getCurrentScope();
   const flagContext = scope.getScopeData().contexts.flags;
   const flagBuffer = flagContext ? flagContext.values : [];
@@ -53,13 +59,17 @@ export function copyFlagsFromScopeToEvent(event: Event): Event {
  * @param value    Value of the feature flag.
  * @param maxSize  Max number of flags the buffer should store. Default value should always be used in production.
  */
-export function insertFlagToScope(name: string, value: unknown, maxSize: number = FLAG_BUFFER_SIZE): void {
+export function _INTERNAL_insertFlagToScope(
+  name: string,
+  value: unknown,
+  maxSize: number = _INTERNAL_FLAG_BUFFER_SIZE,
+): void {
   const scopeContexts = getCurrentScope().getScopeData().contexts;
   if (!scopeContexts.flags) {
     scopeContexts.flags = { values: [] };
   }
   const flags = scopeContexts.flags.values as FeatureFlag[];
-  insertToFlagBuffer(flags, name, value, maxSize);
+  _INTERNAL_insertToFlagBuffer(flags, name, value, maxSize);
 }
 
 /**
@@ -74,7 +84,12 @@ export function insertFlagToScope(name: string, value: unknown, maxSize: number
  * @param value      Value of the feature flag.
  * @param maxSize    Max number of flags the buffer should store. Default value should always be used in production.
  */
-export function insertToFlagBuffer(flags: FeatureFlag[], name: string, value: unknown, maxSize: number): void {
+export function _INTERNAL_insertToFlagBuffer(
+  flags: FeatureFlag[],
+  name: string,
+  value: unknown,
+  maxSize: number,
+): void {
   if (typeof value !== 'boolean') {
     return;
   }
@@ -113,10 +128,10 @@ export function insertToFlagBuffer(flags: FeatureFlag[], name: string, value: un
  * @param value            Value of the feature flag. Non-boolean values are ignored.
  * @param maxFlagsPerSpan  Max number of flags a buffer should store. Default value should always be used in production.
  */
-export function addFeatureFlagToActiveSpan(
+export function _INTERNAL_addFeatureFlagToActiveSpan(
   name: string,
   value: unknown,
-  maxFlagsPerSpan: number = MAX_FLAGS_PER_SPAN,
+  maxFlagsPerSpan: number = _INTERNAL_MAX_FLAGS_PER_SPAN,
 ): void {
   const spanFlagMap = GLOBAL_OBJ._spanToFlagBufferMap;
   if (!spanFlagMap || typeof value !== 'boolean') {
diff --git a/packages/browser/test/utils/featureFlags.test.ts b/packages/core/test/lib/utils/featureFlags.test.ts
similarity index 62%
rename from packages/browser/test/utils/featureFlags.test.ts
rename to packages/core/test/lib/utils/featureFlags.test.ts
index 1c0bed312590..14258c2caf36 100644
--- a/packages/browser/test/utils/featureFlags.test.ts
+++ b/packages/core/test/lib/utils/featureFlags.test.ts
@@ -1,16 +1,20 @@
-import type { FeatureFlag } from '@sentry/core';
-import { getCurrentScope, logger } from '@sentry/core';
 import { afterEach, describe, expect, it, vi } from 'vitest';
-import { insertFlagToScope, insertToFlagBuffer } from '../../src/utils/featureFlags';
+import { getCurrentScope } from '../../../src/currentScopes';
+import {
+  type FeatureFlag,
+  _INTERNAL_insertFlagToScope,
+  _INTERNAL_insertToFlagBuffer,
+} from '../../../src/utils/featureFlags';
+import { logger } from '../../../src/utils-hoist/logger';
 
 describe('flags', () => {
   describe('insertFlagToScope()', () => {
     it('adds flags to the current scope context', () => {
       const maxSize = 3;
-      insertFlagToScope('feat1', true, maxSize);
-      insertFlagToScope('feat2', true, maxSize);
-      insertFlagToScope('feat3', true, maxSize);
-      insertFlagToScope('feat4', true, maxSize);
+      _INTERNAL_insertFlagToScope('feat1', true, maxSize);
+      _INTERNAL_insertFlagToScope('feat2', true, maxSize);
+      _INTERNAL_insertFlagToScope('feat3', true, maxSize);
+      _INTERNAL_insertFlagToScope('feat4', true, maxSize);
 
       const scope = getCurrentScope();
       expect(scope.getScopeData().contexts.flags?.values).toEqual([
@@ -31,10 +35,10 @@ describe('flags', () => {
     it('maintains ordering and evicts the oldest entry', () => {
       const buffer: FeatureFlag[] = [];
       const maxSize = 3;
-      insertToFlagBuffer(buffer, 'feat1', true, maxSize);
-      insertToFlagBuffer(buffer, 'feat2', true, maxSize);
-      insertToFlagBuffer(buffer, 'feat3', true, maxSize);
-      insertToFlagBuffer(buffer, 'feat4', true, maxSize);
+      _INTERNAL_insertToFlagBuffer(buffer, 'feat1', true, maxSize);
+      _INTERNAL_insertToFlagBuffer(buffer, 'feat2', true, maxSize);
+      _INTERNAL_insertToFlagBuffer(buffer, 'feat3', true, maxSize);
+      _INTERNAL_insertToFlagBuffer(buffer, 'feat4', true, maxSize);
 
       expect(buffer).toEqual([
         { flag: 'feat2', result: true },
@@ -46,11 +50,11 @@ describe('flags', () => {
     it('does not duplicate same-name flags and updates order and values', () => {
       const buffer: FeatureFlag[] = [];
       const maxSize = 3;
-      insertToFlagBuffer(buffer, 'feat1', true, maxSize);
-      insertToFlagBuffer(buffer, 'feat2', true, maxSize);
-      insertToFlagBuffer(buffer, 'feat3', true, maxSize);
-      insertToFlagBuffer(buffer, 'feat3', false, maxSize);
-      insertToFlagBuffer(buffer, 'feat1', false, maxSize);
+      _INTERNAL_insertToFlagBuffer(buffer, 'feat1', true, maxSize);
+      _INTERNAL_insertToFlagBuffer(buffer, 'feat2', true, maxSize);
+      _INTERNAL_insertToFlagBuffer(buffer, 'feat3', true, maxSize);
+      _INTERNAL_insertToFlagBuffer(buffer, 'feat3', false, maxSize);
+      _INTERNAL_insertToFlagBuffer(buffer, 'feat1', false, maxSize);
 
       expect(buffer).toEqual([
         { flag: 'feat2', result: true },
@@ -62,8 +66,8 @@ describe('flags', () => {
     it('does not allocate unnecessary space', () => {
       const buffer: FeatureFlag[] = [];
       const maxSize = 1000;
-      insertToFlagBuffer(buffer, 'feat1', true, maxSize);
-      insertToFlagBuffer(buffer, 'feat2', true, maxSize);
+      _INTERNAL_insertToFlagBuffer(buffer, 'feat1', true, maxSize);
+      _INTERNAL_insertToFlagBuffer(buffer, 'feat2', true, maxSize);
 
       expect(buffer).toEqual([
         { flag: 'feat1', result: true },
@@ -74,8 +78,8 @@ describe('flags', () => {
     it('does not accept non-boolean values', () => {
       const buffer: FeatureFlag[] = [];
       const maxSize = 1000;
-      insertToFlagBuffer(buffer, 'feat1', 1, maxSize);
-      insertToFlagBuffer(buffer, 'feat2', 'string', maxSize);
+      _INTERNAL_insertToFlagBuffer(buffer, 'feat1', 1, maxSize);
+      _INTERNAL_insertToFlagBuffer(buffer, 'feat2', 'string', maxSize);
 
       expect(buffer).toEqual([]);
     });
@@ -86,7 +90,7 @@ describe('flags', () => {
         { flag: 'feat2', result: true },
       ];
 
-      insertToFlagBuffer(buffer, 'feat1', true, 1);
+      _INTERNAL_insertToFlagBuffer(buffer, 'feat1', true, 1);
       expect(loggerSpy).toHaveBeenCalledWith(
         expect.stringContaining('[Feature Flags] insertToFlagBuffer called on a buffer larger than maxSize'),
       );
@@ -95,7 +99,7 @@ describe('flags', () => {
         { flag: 'feat2', result: true },
       ]);
 
-      insertToFlagBuffer(buffer, 'feat1', true, -2);
+      _INTERNAL_insertToFlagBuffer(buffer, 'feat1', true, -2);
       expect(loggerSpy).toHaveBeenCalledWith(
         expect.stringContaining('[Feature Flags] insertToFlagBuffer called on a buffer larger than maxSize'),
       );
diff --git a/packages/deno/src/index.ts b/packages/deno/src/index.ts
index f388de7cb5ee..12bcedc35270 100644
--- a/packages/deno/src/index.ts
+++ b/packages/deno/src/index.ts
@@ -8,6 +8,7 @@ export type {
   EventHint,
   ErrorEvent,
   Exception,
+  FeatureFlagsIntegration,
   Session,
   SeverityLevel,
   Span,
@@ -87,6 +88,7 @@ export {
   spanToBaggageHeader,
   updateSpanName,
   wrapMcpServerWithSentry,
+  featureFlagsIntegration,
 } from '@sentry/core';
 
 export { DenoClient } from './client';
diff --git a/packages/google-cloud-serverless/src/index.ts b/packages/google-cloud-serverless/src/index.ts
index f2622e591497..e9586a9bd820 100644
--- a/packages/google-cloud-serverless/src/index.ts
+++ b/packages/google-cloud-serverless/src/index.ts
@@ -121,6 +121,8 @@ export {
   consoleLoggingIntegration,
   wrapMcpServerWithSentry,
   NODE_VERSION,
+  featureFlagsIntegration,
+  type FeatureFlagsIntegration,
 } from '@sentry/node';
 
 export {
diff --git a/packages/node/src/index.ts b/packages/node/src/index.ts
index 589937b21fd4..cf951c3db8b6 100644
--- a/packages/node/src/index.ts
+++ b/packages/node/src/index.ts
@@ -139,6 +139,7 @@ export {
   consoleLoggingIntegration,
   consoleIntegration,
   wrapMcpServerWithSentry,
+  featureFlagsIntegration,
 } from '@sentry/core';
 
 export type {
@@ -158,6 +159,7 @@ export type {
   Thread,
   User,
   Span,
+  FeatureFlagsIntegration,
 } from '@sentry/core';
 
 export { logger };
diff --git a/packages/remix/src/cloudflare/index.ts b/packages/remix/src/cloudflare/index.ts
index 3d3d17e1da27..46c443cac39f 100644
--- a/packages/remix/src/cloudflare/index.ts
+++ b/packages/remix/src/cloudflare/index.ts
@@ -32,6 +32,7 @@ export type {
   EventHint,
   ErrorEvent,
   Exception,
+  FeatureFlagsIntegration,
   Session,
   SeverityLevel,
   Span,
@@ -109,4 +110,5 @@ export {
   spanToTraceHeader,
   spanToBaggageHeader,
   updateSpanName,
+  featureFlagsIntegration,
 } from '@sentry/core';
diff --git a/packages/sveltekit/src/worker/index.ts b/packages/sveltekit/src/worker/index.ts
index 3614922072ec..2dde8c61a1dc 100644
--- a/packages/sveltekit/src/worker/index.ts
+++ b/packages/sveltekit/src/worker/index.ts
@@ -82,6 +82,8 @@ export {
   supabaseIntegration,
   instrumentSupabaseClient,
   zodErrorsIntegration,
+  featureFlagsIntegration,
+  type FeatureFlagsIntegration,
 } from '@sentry/cloudflare';
 
 /**
diff --git a/packages/vercel-edge/src/index.ts b/packages/vercel-edge/src/index.ts
index ff1231c8a1f8..303d40144ec3 100644
--- a/packages/vercel-edge/src/index.ts
+++ b/packages/vercel-edge/src/index.ts
@@ -8,6 +8,7 @@ export type {
   EventHint,
   ErrorEvent,
   Exception,
+  FeatureFlagsIntegration,
   Session,
   SeverityLevel,
   Span,
@@ -90,6 +91,7 @@ export {
   spanToBaggageHeader,
   wrapMcpServerWithSentry,
   consoleLoggingIntegration,
+  featureFlagsIntegration,
 } from '@sentry/core';
 
 export { VercelEdgeClient } from './client';