diff --git a/packages/sdk/svelte/__tests__/lib/client/SvelteLDClient.test.ts b/packages/sdk/svelte/__tests__/lib/client/SvelteLDClient.test.ts
index ea689d6eda..01b332016d 100644
--- a/packages/sdk/svelte/__tests__/lib/client/SvelteLDClient.test.ts
+++ b/packages/sdk/svelte/__tests__/lib/client/SvelteLDClient.test.ts
@@ -2,11 +2,11 @@ import { EventEmitter } from 'node:events';
 import { get } from 'svelte/store';
 import { afterEach, beforeEach, describe, expect, it, Mock, vi } from 'vitest';
 
-import { initialize, LDClient } from '@launchdarkly/js-client-sdk/compat';
+import { createClient, LDClient } from '@launchdarkly/js-client-sdk';
 
 import { LD } from '../../../src/lib/client/SvelteLDClient';
 
-vi.mock('@launchdarkly/js-client-sdk/compat', { spy: true });
+vi.mock('@launchdarkly/js-client-sdk', { spy: true });
 
 const clientSideID = 'test-client-side-id';
 const rawFlags = { 'test-flag': true, 'another-test-flag': 'flag-value' };
@@ -21,6 +21,7 @@ const mockLDClient = {
   allFlags: vi.fn().mockReturnValue(rawFlags),
   variation: vi.fn((_, defaultValue) => defaultValue),
   identify: vi.fn(),
+  start: vi.fn(),
 };
 
 describe('launchDarkly', () => {
@@ -40,8 +41,7 @@ describe('launchDarkly', () => {
       const ld = LD;
 
       beforeEach(() => {
-        // mocks the initialize function to return the mockLDClient
-        (initialize as Mock<typeof initialize>).mockReturnValue(
+        (createClient as Mock<typeof createClient>).mockReturnValue(
           mockLDClient as unknown as LDClient,
         );
       });
@@ -66,7 +66,7 @@ describe('launchDarkly', () => {
         ld.initialize(clientSideID, mockContext);
 
         expect(get(initializing)).toBe(true); // should be true before the ready event is emitted
-        mockLDEventEmitter.emit('ready');
+        mockLDEventEmitter.emit('initialized');
 
         expect(get(initializing)).toBe(false);
       });
@@ -74,7 +74,7 @@ describe('launchDarkly', () => {
       it('should initialize the LaunchDarkly SDK instance', () => {
         ld.initialize(clientSideID, mockContext);
 
-        expect(initialize).toHaveBeenCalledWith('test-client-side-id', mockContext);
+        expect(createClient).toHaveBeenCalledWith('test-client-side-id', mockContext, undefined);
       });
 
       it('should register function that gets flag values when client is ready', () => {
@@ -82,7 +82,7 @@ describe('launchDarkly', () => {
         const allFlagsSpy = vi.spyOn(mockLDClient, 'allFlags').mockReturnValue(newFlags);
 
         ld.initialize(clientSideID, mockContext);
-        mockLDEventEmitter.emit('ready');
+        mockLDEventEmitter.emit('initialized');
 
         expect(allFlagsSpy).toHaveBeenCalledOnce();
         expect(allFlagsSpy).toHaveReturnedWith(newFlags);
@@ -104,8 +104,7 @@ describe('launchDarkly', () => {
       const ld = LD;
 
       beforeEach(() => {
-        // mocks the initialize function to return the mockLDClient
-        (initialize as Mock<typeof initialize>).mockReturnValue(
+        (createClient as Mock<typeof createClient>).mockReturnValue(
           mockLDClient as unknown as LDClient,
         );
       });
@@ -166,8 +165,7 @@ describe('launchDarkly', () => {
       const ld = LD;
 
       beforeEach(() => {
-        // mocks the initialize function to return the mockLDClient
-        (initialize as Mock<typeof initialize>).mockReturnValue(
+        (createClient as Mock<typeof createClient>).mockReturnValue(
           mockLDClient as unknown as LDClient,
         );
       });
@@ -191,8 +189,7 @@ describe('launchDarkly', () => {
       const ld = LD;
 
       beforeEach(() => {
-        // mocks the initialize function to return the mockLDClient
-        (initialize as Mock<typeof initialize>).mockReturnValue(
+        (createClient as Mock<typeof createClient>).mockReturnValue(
           mockLDClient as unknown as LDClient,
         );
       });
diff --git a/packages/sdk/svelte/src/lib/client/SvelteLDClient.ts b/packages/sdk/svelte/src/lib/client/SvelteLDClient.ts
index 21fc32ffb5..83a4e849a9 100644
--- a/packages/sdk/svelte/src/lib/client/SvelteLDClient.ts
+++ b/packages/sdk/svelte/src/lib/client/SvelteLDClient.ts
@@ -1,12 +1,13 @@
 import { derived, type Readable, readonly, writable, type Writable } from 'svelte/store';
 
-import type { LDFlagSet } from '@launchdarkly/js-client-sdk';
 import {
-  initialize,
+  createClient as createClientSdk,
   type LDClient,
   type LDContext,
+  type LDFlagSet,
   type LDFlagValue,
-} from '@launchdarkly/js-client-sdk/compat';
+  type LDOptions,
+} from '@launchdarkly/js-client-sdk';
 
 export type { LDContext, LDFlagValue };
 
@@ -62,7 +63,7 @@ function toFlagsProxy(client: LDClient, flags: LDFlags): LDFlags {
  * Creates a LaunchDarkly instance.
  * @returns {Object} The LaunchDarkly instance object.
  */
-function createLD() {
+function init() {
   let coreLdClient: LDClient | undefined;
   const loading = writable(true);
   const flagsWritable = writable<LDFlags>({});
@@ -73,21 +74,23 @@ function createLD() {
    * @param {LDContext} context - The user context.
    * @returns {Object} An object with the initialization status store.
    */
-  function LDInitialize(clientId: LDClientID, context: LDContext) {
-    coreLdClient = initialize(clientId, context);
-    coreLdClient!.on('ready', () => {
+  function initialize(clientId: LDClientID, context: LDContext, options?: LDOptions) {
+    coreLdClient = createClientSdk(clientId, context, options);
+    coreLdClient.on('initialized', () => {
       loading.set(false);
       const rawFlags = coreLdClient!.allFlags();
       const allFlags = toFlagsProxy(coreLdClient!, rawFlags);
       flagsWritable.set(allFlags);
     });
 
-    coreLdClient!.on('change', () => {
+    coreLdClient.on('change', () => {
       const rawFlags = coreLdClient!.allFlags();
       const allFlags = toFlagsProxy(coreLdClient!, rawFlags);
       flagsWritable.set(allFlags);
     });
 
+    coreLdClient.start();
+
     return {
       initializing: loading,
     };
@@ -125,7 +128,7 @@ function createLD() {
   return {
     identify,
     flags: readonly(flagsWritable),
-    initialize: LDInitialize,
+    initialize,
     initializing: readonly(loading),
     watch,
     useFlag,
@@ -133,4 +136,4 @@ function createLD() {
 }
 
 /** The LaunchDarkly instance */
-export const LD = createLD();
+export const LD = init();