diff --git a/src/controllers/ExtensionController.ts b/src/controllers/ExtensionController.ts
index 5e94d21a..ea6927b6 100644
--- a/src/controllers/ExtensionController.ts
+++ b/src/controllers/ExtensionController.ts
@@ -66,6 +66,7 @@ import type {
   CoreAuthenticatedClient,
   ICoreClientFactory,
   CoreUnauthenticatedClient,
+  WorkerURL,
 } from '../types';
 import { ServerConnectionTreeDragAndDropController } from './ServerConnectionTreeDragAndDropController';
 import { ConnectionController } from './ConnectionController';
@@ -113,6 +114,8 @@ export class ExtensionController implements Disposable {
     this.initializeWebViews();
     this.initializeServerUpdates();
 
+    this._context.subscriptions.push(NodeHttp2gRPCTransport);
+
     logger.info(
       'Congratulations, your extension "vscode-deephaven" is now active!'
     );
@@ -342,14 +345,27 @@ export class ExtensionController implements Disposable {
       url: URL
     ): Promise<CoreUnauthenticatedClient & Disposable> => {
       assertDefined(this._coreJsApiCache, 'coreJsApiCache');
+
+      const workerInfo = await this._serverManager?.getWorkerInfo(
+        url as WorkerURL
+      );
+
       const dhc = await this._coreJsApiCache.get(url);
 
-      const client = new dhc.CoreClient(url.toString(), {
-        debug: true,
-        // TODO: This should be optional, but types aren't happy yet
-        headers: {},
-        transportFactory: NodeHttp2gRPCTransport.factory,
-      }) as CoreUnauthenticatedClient;
+      const clientUrl = workerInfo == null ? url : workerInfo.grpcUrl;
+      const envoyPrefix = workerInfo?.envoyPrefix;
+
+      const headers: { [key: string]: string } =
+        // eslint-disable-next-line @typescript-eslint/naming-convention
+        envoyPrefix == null ? {} : { 'envoy-prefix': envoyPrefix };
+
+      const client = new dhc.CoreClient(
+        clientUrl.toString().replace(/\/$/, ''),
+        {
+          headers,
+          transportFactory: NodeHttp2gRPCTransport.factory,
+        }
+      ) as CoreUnauthenticatedClient;
 
       // Attach a dispose method so that client caches can dispose of the client
       return Object.assign(client, {
diff --git a/src/controllers/PanelController.ts b/src/controllers/PanelController.ts
index 3a2839c7..624ac42f 100644
--- a/src/controllers/PanelController.ts
+++ b/src/controllers/PanelController.ts
@@ -4,6 +4,7 @@ import type {
   IPanelService,
   IServerManager,
   VariableDefintion,
+  WorkerInfo,
   WorkerURL,
 } from '../types';
 import {
@@ -192,8 +193,8 @@ export class PanelController extends ControllerBase {
     const connection = this._serverManager.getConnection(serverUrl);
     assertDefined(connection, 'connection');
 
-    const isWorkerUrl = Boolean(
-      await this._serverManager.getWorkerInfo(serverUrl as WorkerURL)
+    const workerInfo = await this._serverManager.getWorkerInfo(
+      serverUrl as WorkerURL
     );
 
     for (const { id, title } of variables) {
@@ -202,7 +203,7 @@ export class PanelController extends ControllerBase {
       const iframeUrl = await getEmbedWidgetUrlForConnection(
         connection,
         title,
-        isWorkerUrl
+        workerInfo
       );
 
       panel.webview.html = getPanelHtml(iframeUrl, title);
@@ -232,7 +233,7 @@ export class PanelController extends ControllerBase {
 export async function getEmbedWidgetUrlForConnection(
   connection: ConnectionState,
   title: string,
-  isWorkerUrl: boolean
+  workerInfo?: WorkerInfo
 ): Promise<URL> {
   return getEmbedWidgetUrl({
     serverUrl: connection.serverUrl,
@@ -241,7 +242,8 @@ export async function getEmbedWidgetUrlForConnection(
     // For Core+ workers in DHE, we use `postMessage` apis for auth where DH
     // iframe communicates with parent (the extension) to get login credentials
     // from the DHE client. See `getPanelHtml` util for more details.
-    authProvider: isWorkerUrl ? 'parent' : undefined,
+    authProvider: workerInfo == null ? undefined : 'parent',
+    envoyPrefix: workerInfo?.envoyPrefix,
     psk:
       connection instanceof DhcService ? await connection.getPsk() : undefined,
   });
diff --git a/src/dh/NodeHttp2gRPCTransport.ts b/src/dh/NodeHttp2gRPCTransport.ts
index b117d615..5640bf24 100644
--- a/src/dh/NodeHttp2gRPCTransport.ts
+++ b/src/dh/NodeHttp2gRPCTransport.ts
@@ -9,6 +9,16 @@ import { assertDefined } from '../util';
 export class NodeHttp2gRPCTransport implements GrpcTransport {
   static _sessionMap: Map<string, http2.ClientHttp2Session> = new Map();
 
+  /**
+   * Cleanup.
+   */
+  static dispose(): void {
+    for (const session of NodeHttp2gRPCTransport._sessionMap.values()) {
+      session.close();
+    }
+    NodeHttp2gRPCTransport._sessionMap.clear();
+  }
+
   /**
    * TODO: Cleanup requests similar to https://github.com/deephaven/deephaven-core/blob/c05b35957e466fded4da61154ba106cfc3198bc5/web/client-api/src/main/java/io/deephaven/web/client/api/grpc/MultiplexedWebsocketTransport.java#L129
    * Create a Transport instance.
@@ -16,7 +26,12 @@ export class NodeHttp2gRPCTransport implements GrpcTransport {
    * @returns Transport instance.
    */
   static readonly factory: GrpcTransportFactory = {
-    create: options => {
+    /**
+     * Create a new transport instance.
+     * @param options - options for creating the transport
+     * @return a transport instance to use for gRPC communication
+     */
+    create: (options): GrpcTransport => {
       const { origin } = new URL(options.url);
 
       if (!NodeHttp2gRPCTransport._sessionMap.has(origin)) {
@@ -126,14 +141,4 @@ export class NodeHttp2gRPCTransport implements GrpcTransport {
     assertDefined(this._request, '_request');
     this._request.close();
   }
-
-  /**
-   * Cleanup.
-   */
-  static dispose(): void {
-    for (const session of NodeHttp2gRPCTransport._sessionMap.values()) {
-      session.close();
-    }
-    NodeHttp2gRPCTransport._sessionMap.clear();
-  }
 }
diff --git a/src/dh/dhc.ts b/src/dh/dhc.ts
index 743b362b..45852b4a 100644
--- a/src/dh/dhc.ts
+++ b/src/dh/dhc.ts
@@ -58,6 +58,7 @@ export async function getDhc(
  * @param title Widget title
  * @param themeKey Theme key
  * @param authProvider Optional auth provider
+ * @param envoyPrefix Optional envoy prefix for Core+ workers
  * @param psk Optional psk
  */
 export function getEmbedWidgetUrl({
@@ -65,15 +66,17 @@ export function getEmbedWidgetUrl({
   title,
   themeKey,
   authProvider,
+  envoyPrefix,
   psk,
 }: {
   serverUrl: URL;
   title: string;
   themeKey: string;
   authProvider?: 'parent';
+  envoyPrefix?: string | null;
   psk?: string | null;
 }): URL {
-  const url = new URL('/iframe/widget', serverUrl);
+  const url = new URL('iframe/widget/', serverUrl);
 
   url.searchParams.set('name', title);
   url.searchParams.set('theme', themeKey);
@@ -82,6 +85,10 @@ export function getEmbedWidgetUrl({
     url.searchParams.set('authProvider', authProvider);
   }
 
+  if (envoyPrefix) {
+    url.searchParams.set('envoyPrefix', envoyPrefix);
+  }
+
   if (psk) {
     url.searchParams.set('psk', psk);
   }
diff --git a/src/dh/dhe.ts b/src/dh/dhe.ts
index 94af90e4..f0b39b93 100644
--- a/src/dh/dhe.ts
+++ b/src/dh/dhe.ts
@@ -10,7 +10,9 @@ import type { AuthenticatedClient as DheAuthenticatedClient } from '@deephaven-e
 import { hasStatusCode, loadModules } from '@deephaven/jsapi-nodejs';
 import type {
   ConsoleType,
+  GrpcURL,
   IdeURL,
+  JsapiURL,
   QuerySerial,
   UniqueID,
   WorkerConfig,
@@ -271,15 +273,22 @@ export async function getWorkerInfoFromQuery(
     return;
   }
 
-  const { grpcUrl, ideUrl, processInfoId, workerName } = queryInfo.designated;
+  const { envoyPrefix, grpcUrl, ideUrl, jsApiUrl, processInfoId, workerName } =
+    queryInfo.designated;
+
+  const workerUrl = new URL(jsApiUrl) as WorkerURL;
+  workerUrl.pathname = workerUrl.pathname.replace(/jsapi\/dh-core.js$/, '');
 
   return {
     tagId,
     serial: querySerial,
-    grpcUrl: new URL(grpcUrl) as WorkerURL,
+    envoyPrefix,
+    grpcUrl: new URL(grpcUrl) as GrpcURL,
     ideUrl: new URL(ideUrl) as IdeURL,
+    jsapiUrl: new URL(jsApiUrl) as JsapiURL,
     processInfoId,
     workerName,
+    workerUrl,
   };
 }
 
diff --git a/src/services/DheService.ts b/src/services/DheService.ts
index dc5e805a..72b85295 100644
--- a/src/services/DheService.ts
+++ b/src/services/DheService.ts
@@ -2,7 +2,6 @@ import * as vscode from 'vscode';
 import type { AuthenticatedClient as DheAuthenticatedClient } from '@deephaven-enterprise/auth-nodejs';
 import type { EnterpriseDhType as DheType } from '@deephaven-enterprise/jsapi-types';
 import {
-  WorkerURL,
   type ConsoleType,
   type IAsyncCacheService,
   type IConfigService,
@@ -13,6 +12,7 @@ import {
   type UniqueID,
   type WorkerConfig,
   type WorkerInfo,
+  type WorkerURL,
 } from '../types';
 import { URLMap } from './URLMap';
 import { Logger } from '../util';
@@ -231,7 +231,7 @@ export class DheService implements IDheService {
       throw new Error('Failed to create worker.');
     }
 
-    this._workerInfoMap.set(workerInfo.grpcUrl, workerInfo);
+    this._workerInfoMap.set(workerInfo.workerUrl, workerInfo);
 
     return workerInfo;
   };
diff --git a/src/services/ServerManager.ts b/src/services/ServerManager.ts
index 18ea0417..ac5371e3 100644
--- a/src/services/ServerManager.ts
+++ b/src/services/ServerManager.ts
@@ -13,12 +13,12 @@ import type {
   WorkerInfo,
   IDheService,
   IAsyncCacheService,
-  WorkerURL,
   UniqueID,
   IToastService,
   CoreAuthenticatedClient,
   ISecretService,
   Psk,
+  WorkerURL,
 } from '../types';
 import {
   getInitialServerStates,
@@ -211,7 +211,7 @@ export class ServerManager implements IServerManager {
         // this indicates that the user cancelled the creation before it was ready.
         // In this case, dispose of the worker.
         if (!this._connectionMap.has(placeholderUrl)) {
-          dheService.deleteWorker(workerInfo.grpcUrl);
+          dheService.deleteWorker(workerInfo.workerUrl);
           this._onDidUpdate.fire();
           return null;
         }
@@ -228,11 +228,14 @@ export class ServerManager implements IServerManager {
 
       // Map the worker URL to the server URL to make things easier to dispose
       // later.
-      this._workerURLToServerURLMap.set(new URL(workerInfo.grpcUrl), serverUrl);
+      this._workerURLToServerURLMap.set(
+        new URL(workerInfo.workerUrl),
+        serverUrl
+      );
 
       // Update the server URL to the worker url to be used below with core
       // connection creation.
-      serverUrl = new URL(workerInfo.grpcUrl);
+      serverUrl = new URL(workerInfo.workerUrl);
     }
 
     const connection = this._dhcServiceFactory.create(serverUrl, tagId);
diff --git a/src/types/commonTypes.d.ts b/src/types/commonTypes.d.ts
index 1b7c15cc..26a81065 100644
--- a/src/types/commonTypes.d.ts
+++ b/src/types/commonTypes.d.ts
@@ -87,17 +87,22 @@ export interface ConnectionState {
   readonly tagId?: UniqueID;
 }
 
-export type WorkerURL = Brand<'GrpcUrl', URL>;
+export type GrpcURL = Brand<'GrpcURL', URL>;
 export type IdeURL = Brand<'IdeUrl', URL>;
+export type JsapiURL = Brand<'JsapiURL', URL>;
 export type QuerySerial = Brand<'QuerySerial', string>;
+export type WorkerURL = Brand<'WorkerURL', URL>;
 
 export interface WorkerInfo {
   tagId: UniqueID;
-  grpcUrl: WorkerURL;
+  envoyPrefix: string | null;
+  grpcUrl: GrpcURL;
   ideUrl: IdeURL;
+  jsapiUrl: JsapiURL;
   processInfoId: string | null;
   serial: QuerySerial;
   workerName: string | null;
+  workerUrl: WorkerURL;
 }
 
 export interface Disposable {
diff --git a/src/types/serviceTypes.d.ts b/src/types/serviceTypes.d.ts
index cbfcc456..498bd33f 100644
--- a/src/types/serviceTypes.d.ts
+++ b/src/types/serviceTypes.d.ts
@@ -8,19 +8,18 @@ import type {
   EventListenerT,
   ConnectionState,
   ServerState,
-  UnsubscribeEventListener,
   VariableChanges,
   VariableDefintion,
   VariableID,
   WorkerInfo,
-  WorkerURL,
   UniqueID,
   UserKeyPairs,
   UserLoginPreferences,
   CoreUnauthenticatedClient,
   Psk,
   CoreAuthenticatedClient,
-} from '../types/commonTypes';
+  WorkerURL,
+} from './commonTypes';
 import type {
   AuthenticatedClient as DheAuthenticatedClient,
   UnauthenticatedClient as DheUnauthenticatedClient,