diff --git a/.changeset/good-impalas-applaud.md b/.changeset/good-impalas-applaud.md
new file mode 100644
index 000000000..df0a6b077
--- /dev/null
+++ b/.changeset/good-impalas-applaud.md
@@ -0,0 +1,8 @@
+---
+"@assistant-ui/react-playground": patch
+"@assistant-ui/react-langgraph": patch
+"@assistant-ui/react-ai-sdk": patch
+"@assistant-ui/react": patch
+---
+
+fix: do not export internal Runtime types
diff --git a/packages/react-playground/src/lib/playground-runtime.ts b/packages/react-playground/src/lib/playground-runtime.ts
index 28bfa5a9d..960ff0778 100644
--- a/packages/react-playground/src/lib/playground-runtime.ts
+++ b/packages/react-playground/src/lib/playground-runtime.ts
@@ -22,6 +22,8 @@ import {
   fromCoreMessage,
   INTERNAL,
   ThreadSuggestion,
+  ThreadRuntime,
+  AssistantRuntime,
 } from "@assistant-ui/react";
 import { LanguageModelV1FunctionTool } from "@ai-sdk/provider";
 import { useMemo, useState } from "react";
@@ -517,7 +519,14 @@ export class PlaygroundThreadRuntimeCore implements INTERNAL.ThreadRuntimeCore {
   }
 }
 
-class PlaygroundThreadRuntime extends ThreadRuntimeImpl {
+type PlaygroundThreadRuntime = ThreadRuntime & {
+  setRequestData: (options: EdgeRuntimeRequestOptions) => void;
+};
+
+class PlaygroundThreadRuntimeImpl
+  extends ThreadRuntimeImpl
+  implements PlaygroundThreadRuntime
+{
   constructor(private binding: INTERNAL.ThreadRuntimeCoreBinding) {
     super(binding);
   }
@@ -529,6 +538,29 @@ class PlaygroundThreadRuntime extends ThreadRuntimeImpl {
   }
 }
 
+export type PlaygroundRuntime = AssistantRuntime & {
+  thread: PlaygroundThreadRuntime;
+};
+
+class PlaygroundRuntimeImpl
+  extends AssistantRuntimeImpl
+  implements PlaygroundRuntime
+{
+  public override get thread() {
+    return super.thread as PlaygroundThreadRuntime;
+  }
+
+  public static override create(_core: PlaygroundRuntimeCore) {
+    return new PlaygroundRuntimeImpl(
+      _core,
+      AssistantRuntimeImpl.createThreadRuntime(
+        _core,
+        PlaygroundThreadRuntimeImpl,
+      ),
+    ) as PlaygroundRuntime;
+  }
+}
+
 export const usePlaygroundRuntime = ({
   initialMessages,
   maxToolRoundtrips,
@@ -545,8 +577,5 @@ export const usePlaygroundRuntime = ({
       ),
   );
 
-  return useMemo(
-    () => new AssistantRuntimeImpl(runtime, PlaygroundThreadRuntime),
-    [runtime],
-  );
+  return useMemo(() => PlaygroundRuntimeImpl.create(runtime), [runtime]);
 };
diff --git a/packages/react/src/api/AssistantRuntime.ts b/packages/react/src/api/AssistantRuntime.ts
index ca3c9d07d..69d31eca7 100644
--- a/packages/react/src/api/AssistantRuntime.ts
+++ b/packages/react/src/api/AssistantRuntime.ts
@@ -1,7 +1,11 @@
 import { AssistantRuntimeCore } from "../runtimes/core/AssistantRuntimeCore";
 import { NestedSubscriptionSubject } from "./subscribable/NestedSubscriptionSubject";
 import { ModelConfigProvider } from "../types/ModelConfigTypes";
-import { ThreadRuntime, ThreadRuntimeCoreBinding } from "./ThreadRuntime";
+import {
+  ThreadRuntime,
+  ThreadRuntimeCoreBinding,
+  ThreadRuntimeImpl,
+} from "./ThreadRuntime";
 import { Unsubscribe } from "../types";
 
 export type AssistantRuntime = {
@@ -23,26 +27,17 @@ export type AssistantRuntime = {
   subscribe(callback: () => void): Unsubscribe;
 };
 
-export class AssistantRuntimeImpl<
-    TThreadRuntime extends ThreadRuntime = ThreadRuntime,
-  >
+export class AssistantRuntimeImpl
   implements AssistantRuntimeCore, AssistantRuntime
 {
-  constructor(
-    private _core: AssistantRuntimeCore,
-    CustomThreadRuntime: new (
-      binding: ThreadRuntimeCoreBinding,
-    ) => TThreadRuntime,
-  ) {
-    this.thread = new CustomThreadRuntime(
-      new NestedSubscriptionSubject({
-        getState: () => this._core.thread,
-        subscribe: (callback) => this._core.subscribe(callback),
-      }),
-    );
-  }
+  protected constructor(
+    private readonly _core: AssistantRuntimeCore,
+    private readonly _thread: ThreadRuntime,
+  ) {}
 
-  public readonly thread;
+  public get thread() {
+    return this._thread;
+  }
 
   public switchToNewThread() {
     return this._core.switchToNewThread();
@@ -68,4 +63,30 @@ export class AssistantRuntimeImpl<
   public subscribe(callback: () => void) {
     return this._core.subscribe(callback);
   }
+
+  protected static createThreadRuntime(
+    _core: AssistantRuntimeCore,
+    CustomThreadRuntime: new (
+      binding: ThreadRuntimeCoreBinding,
+    ) => ThreadRuntime = ThreadRuntimeImpl,
+  ) {
+    return new CustomThreadRuntime(
+      new NestedSubscriptionSubject({
+        getState: () => _core.thread,
+        subscribe: (callback) => _core.subscribe(callback),
+      }),
+    );
+  }
+
+  public static create(
+    _core: AssistantRuntimeCore,
+    CustomThreadRuntime: new (
+      binding: ThreadRuntimeCoreBinding,
+    ) => ThreadRuntime = ThreadRuntimeImpl,
+  ) {
+    return new AssistantRuntimeImpl(
+      _core,
+      AssistantRuntimeImpl.createThreadRuntime(_core, CustomThreadRuntime),
+    ) as AssistantRuntime;
+  }
 }
diff --git a/packages/react/src/runtimes/external-store/useExternalStoreRuntime.tsx b/packages/react/src/runtimes/external-store/useExternalStoreRuntime.tsx
index 824fa87f6..a077603bf 100644
--- a/packages/react/src/runtimes/external-store/useExternalStoreRuntime.tsx
+++ b/packages/react/src/runtimes/external-store/useExternalStoreRuntime.tsx
@@ -12,7 +12,7 @@ export const useExternalStoreRuntime = <T,>(store: ExternalStoreAdapter<T>) => {
   });
 
   return useMemo(
-    () => new AssistantRuntimeImpl(runtime, ThreadRuntimeImpl),
+    () => AssistantRuntimeImpl.create(runtime, ThreadRuntimeImpl),
     [runtime],
   );
 };
diff --git a/packages/react/src/runtimes/local/useLocalRuntime.tsx b/packages/react/src/runtimes/local/useLocalRuntime.tsx
index 6d55e0a50..cf12ee4ce 100644
--- a/packages/react/src/runtimes/local/useLocalRuntime.tsx
+++ b/packages/react/src/runtimes/local/useLocalRuntime.tsx
@@ -4,17 +4,35 @@ import { useInsertionEffect, useMemo, useState } from "react";
 import type { ChatModelAdapter } from "./ChatModelAdapter";
 import { LocalRuntimeCore } from "./LocalRuntimeCore";
 import { LocalRuntimeOptions } from "./LocalRuntimeOptions";
-import { AssistantRuntimeImpl } from "../../api/AssistantRuntime";
-import { ThreadRuntimeImpl } from "../../api/ThreadRuntime";
+import {
+  AssistantRuntime,
+  AssistantRuntimeImpl,
+} from "../../api/AssistantRuntime";
+import { ThreadRuntimeImpl } from "../../internal";
+import { ThreadRuntime } from "../../api";
 
-export class LocalRuntime extends AssistantRuntimeImpl {
-  constructor(private core: LocalRuntimeCore) {
-    super(core, ThreadRuntimeImpl);
+export type LocalRuntime = AssistantRuntime & {
+  reset: (options?: Parameters<LocalRuntimeCore["reset"]>[0]) => void;
+};
+
+class LocalRuntimeImpl extends AssistantRuntimeImpl implements LocalRuntime {
+  private constructor(
+    private core: LocalRuntimeCore,
+    thread: ThreadRuntime,
+  ) {
+    super(core, thread);
   }
 
   public reset(options?: Parameters<LocalRuntimeCore["reset"]>[0]) {
     this.core.reset(options);
   }
+
+  public static override create(_core: LocalRuntimeCore) {
+    return new LocalRuntimeImpl(
+      _core,
+      AssistantRuntimeImpl.createThreadRuntime(_core, ThreadRuntimeImpl),
+    ) as LocalRuntime;
+  }
 }
 
 export const useLocalRuntime = (
@@ -28,5 +46,5 @@ export const useLocalRuntime = (
     runtime.thread.options = options;
   });
 
-  return useMemo(() => new LocalRuntime(runtime), [runtime]);
+  return useMemo(() => LocalRuntimeImpl.create(runtime), [runtime]);
 };