diff --git a/packages/react/src/runtime/core/BaseAssistantRuntime.tsx b/packages/react/src/runtime/core/BaseAssistantRuntime.tsx
index 9b69ee2ae4..841b56cb4f 100644
--- a/packages/react/src/runtime/core/BaseAssistantRuntime.tsx
+++ b/packages/react/src/runtime/core/BaseAssistantRuntime.tsx
@@ -1,13 +1,29 @@
+import { ReactThreadRuntime } from "../../../dist";
 import type { AppendMessage } from "../../types/AssistantTypes";
 import { type ModelConfigProvider } from "../../types/ModelConfigTypes";
 import type { Unsubscribe } from "../../types/Unsubscribe";
 import type { AssistantRuntime } from "./AssistantRuntime";
-import { ThreadRuntime } from "./ThreadRuntime";
 
-export abstract class BaseAssistantRuntime<TThreadRuntime extends ThreadRuntime>
-  implements AssistantRuntime
+export abstract class BaseAssistantRuntime<
+  TThreadRuntime extends ReactThreadRuntime,
+> implements AssistantRuntime
 {
-  constructor(protected thread: TThreadRuntime) {}
+  constructor(private _thread: TThreadRuntime) {
+    this._thread = _thread;
+    this._unsubscribe = this._thread.subscribe(this.subscriptionHandler);
+  }
+
+  private _unsubscribe: Unsubscribe;
+
+  get thread() {
+    return this._thread;
+  }
+
+  set thread(thread: TThreadRuntime) {
+    this._unsubscribe();
+    this._thread = thread;
+    this._unsubscribe = this._thread.subscribe(this.subscriptionHandler);
+  }
 
   public abstract registerModelConfigProvider(
     provider: ModelConfigProvider,
@@ -46,7 +62,18 @@ export abstract class BaseAssistantRuntime<TThreadRuntime extends ThreadRuntime>
     return this.thread.addToolResult(toolCallId, result);
   }
 
+  private _subscriptions = new Set<() => void>();
+
   public subscribe(callback: () => void): Unsubscribe {
-    return this.thread.subscribe(callback);
+    this._subscriptions.add(callback);
+    return () => this._subscriptions.delete(callback);
+  }
+
+  private subscriptionHandler = () => {
+    for (const callback of this._subscriptions) callback();
+  };
+
+  public get unstable_synchronizer() {
+    return this.thread.unstable_synchronizer;
   }
 }