diff --git a/lib/core/TokenSet.ts b/lib/core/TokenSet.ts
new file mode 100644
index 000000000..041e98cd0
--- /dev/null
+++ b/lib/core/TokenSet.ts
@@ -0,0 +1,55 @@
+import { OktaAuthCoreInterface } from './types';
+import { TokenManager } from '../oidc';
+import { TOKEN_STORAGE_NAME } from '../constants';
+import { ServiceManager } from './ServiceManager';
+
+export class TokenSet {
+  private sdk: OktaAuthCoreInterface;
+  private map: Map<string, any>; // TODO: add type
+
+  constructor(sdk: OktaAuthCoreInterface) {
+    this.sdk = sdk;
+
+    this.map = new Map();
+    const options = sdk.options;
+    const tokenManager = new TokenManager(this.sdk, options.tokenManager);
+    const serviceManager = new ServiceManager(this.sdk, options.services);
+    this.map.set(TOKEN_STORAGE_NAME, {
+      tokenManager,
+      serviceManager,
+    });
+  }
+
+  start(key?: string) {
+    // start services for one or all token sets
+  }
+
+  stop(key?: string) {
+    // stop services for one or all token sets
+  }
+
+  // call this method when need to add a new token set, like after receiving new tokens from authorize/idx
+  addTokenSet(tokens, options) {
+    const storageKey = options.storageKey;
+    const tokenManager = new TokenManager(this.sdk, options.tokenManager); // with specific storageKey
+    const serviceManager = new ServiceManager(this.sdk, options.services);
+    this.map.set(storageKey, {
+      tokenManager,
+      serviceManager,
+    });
+
+    tokenManager.setTokens(tokens);
+
+    if (options.default) {
+      this.useTokenSet(options.tokenManager.storageKey);
+    }
+  }
+
+  useTokenSet(key) {
+    const tokenSet = this.map.get(key);
+    this.sdk.tokenManager = tokenSet.tokenManager;
+    this.sdk.serviceManager = tokenSet.serviceManager;
+    // sync authState with new token set
+    this.sdk.authStateManager.updateAuthState();
+  }
+}
diff --git a/lib/core/mixin.ts b/lib/core/mixin.ts
index a81c74e80..340363b56 100644
--- a/lib/core/mixin.ts
+++ b/lib/core/mixin.ts
@@ -11,6 +11,7 @@ import {
 import { AuthStateManager } from './AuthStateManager';
 import { ServiceManager } from './ServiceManager';
 import { OktaAuthCoreInterface, OktaAuthCoreOptions } from './types';
+import { TokenSet } from './TokenSet';
 
 export function mixinCore
 <
@@ -27,6 +28,7 @@ export function mixinCore
   {
     authStateManager: AuthStateManager<M, S, O>;
     serviceManager: ServiceManager<M, S, O>;
+    tokenSet: TokenSet;
     
     constructor(...args: any[]) {
       super(...args);
@@ -34,8 +36,8 @@ export function mixinCore
       // AuthStateManager
       this.authStateManager = new AuthStateManager<M, S, O>(this);
 
-      // ServiceManager
-      this.serviceManager = new ServiceManager<M, S, O>(this, this.options.services);
+      this.tokenSet = new TokenSet(this);
+      this.tokenSet.useTokenSet(this.options.tokenManager.storageKey);
     }
 
     async start() {
diff --git a/lib/oidc/TokenManager.ts b/lib/oidc/TokenManager.ts
index 07a626588..178f6c26b 100644
--- a/lib/oidc/TokenManager.ts
+++ b/lib/oidc/TokenManager.ts
@@ -105,7 +105,7 @@ export class TokenManager implements TokenManagerInterface {
   // eslint-disable-next-line complexity
   constructor(sdk: OktaAuthOAuthInterface, options: TokenManagerOptions = {}) {
     this.sdk = sdk;
-    this.emitter = (sdk as any).emitter;
+    this.emitter = new EventEmitter();
     if (!this.emitter) {
       throw new AuthSdkError('Emitter should be initialized before TokenManager');
     }