From 10b8eba4be04769dfc3e4533d30db543cfbd0040 Mon Sep 17 00:00:00 2001
From: jeremyphilemon <git@jrmyphlmn.com>
Date: Fri, 25 Apr 2025 09:22:32 -0700
Subject: [PATCH 01/20] feat (ui/react): support resuming an ongoing stream

---
 .changeset/nine-pillows-hug.md                |   6 +
 content/docs/04-ai-sdk-ui/02-chatbot.mdx      |  71 +++++++
 examples/next-openai/.gitignore               |   3 +-
 .../app/api/use-chat-resume/route.ts          | 102 +++++++++
 .../app/use-chat-resume/[id]/page.tsx         |  14 ++
 .../next-openai/app/use-chat-resume/chat.tsx  | 109 ++++++++++
 .../next-openai/app/use-chat-resume/page.tsx  |   8 +
 examples/next-openai/package.json             |  12 +-
 examples/next-openai/util/chat-store.ts       |  50 ++++-
 packages/react/src/use-chat.ts                | 106 ++++++++++
 packages/react/src/use-chat.ui.test.tsx       |  50 +++++
 packages/ui-utils/src/call-chat-api.ts        |  88 ++++++++
 packages/ui-utils/src/index.ts                |   2 +-
 pnpm-lock.yaml                                | 196 +++++++++++++++---
 turbo.json                                    |  40 +++-
 15 files changed, 816 insertions(+), 41 deletions(-)
 create mode 100644 .changeset/nine-pillows-hug.md
 create mode 100644 examples/next-openai/app/api/use-chat-resume/route.ts
 create mode 100644 examples/next-openai/app/use-chat-resume/[id]/page.tsx
 create mode 100644 examples/next-openai/app/use-chat-resume/chat.tsx
 create mode 100644 examples/next-openai/app/use-chat-resume/page.tsx

diff --git a/.changeset/nine-pillows-hug.md b/.changeset/nine-pillows-hug.md
new file mode 100644
index 000000000000..5ff42392b2e0
--- /dev/null
+++ b/.changeset/nine-pillows-hug.md
@@ -0,0 +1,6 @@
+---
+'@ai-sdk/ui-utils': patch
+'@ai-sdk/react': patch
+---
+
+feat (ui/react): support resuming an ongoing stream
diff --git a/content/docs/04-ai-sdk-ui/02-chatbot.mdx b/content/docs/04-ai-sdk-ui/02-chatbot.mdx
index 8611213b06ba..6494a2d06c13 100644
--- a/content/docs/04-ai-sdk-ui/02-chatbot.mdx
+++ b/content/docs/04-ai-sdk-ui/02-chatbot.mdx
@@ -634,6 +634,77 @@ messages.map(message => (
 ));
 ```
 
+## Resumable Streams (Experimental)
+
+The `useChat` hook has experimental support for resuming an ongoing chat generation stream by any client, either after a network disconnect or reloading the chat. This can be useful for building applications that involve long-running conversations or for ensuring that messages are not lost in case of network failures.
+
+The following are the pre-requisities for your chat application to support resumable streams:
+
+- Installing the [`resumable-stream`](https://www.npmjs.com/package/resumable-stream) package that helps create and manage the publisher/subscriber mechanism of the streams.
+- A [Redis](https://vercel.com/marketplace/redis) instance to store the stream state.
+- A table that tracks the stream IDs associated with a chat.
+
+To resume a chat stream, you can use the `experimental_resume` function returned by the `useChat` hook. You will typically call this function during the initial mount of the hook.
+
+```
+'use client'
+
+export function Chat() {
+  const { experimental_resume } = useChat({id});
+
+  useEffect(() => {
+    experimental_resume();
+
+    // we use an empty dependency array to
+    // ensure this effect runs only once
+  }, [])
+
+  return (
+    <div>
+      <Messages>
+      <Input/>
+    </div>
+  )
+}
+```
+
+The `experimental_resume` function makes a `GET` request to the api endpoint you've initialized the hook with (or `/api/chat` by default) and streams the contents of the stream if it is active or fails silently if it has ended.
+
+The `GET` request automatically appends the `chatId` query parameter to the URL to help identify the chat the request belongs to. Using the `chatId`, you can look up the most recent stream ID from the database and resume the stream. As a result, it is important to specify the `id` parameter in the `useChat` hook.
+
+Earlier, you must've implemented the `POST` method for `/api/chat` route to create new chat generations. When using `experimental_resume`, you must also implement the `GET` method for `/api/chat` route to resume a stream if it is active or fails silently if it has ended.
+
+```
+export async function GET() {
+  const { searchParams } = new URL(request.url);
+  const chatId = searchParams.get('chatId');
+
+  if (!chatId) {
+    return new Response('id is required', { status: 400 });
+  }
+
+  const streamIds = await loadStreams(chatId);
+
+  if (!streamIds.length) {
+    return new Response('No streams found', { status: 404 });
+  }
+
+  const recentStreamId = streamIds.at(-1);
+
+  if (!recentStreamId) {
+    return new Response('No recent stream found', { status: 404 });
+  }
+
+  const emptyDataStream = createDataStream({
+    execute: () => {},
+  });
+
+  return new Response(
+    await streamContext.resumableStream(recentStreamId, () => emptyDataStream),
+  );
+}
+```
+
 ## Attachments (Experimental)
 
 The `useChat` hook supports sending attachments along with a message as well as rendering them on the client. This can be useful for building applications that involve sending images, files, or other media content to the AI provider.
diff --git a/examples/next-openai/.gitignore b/examples/next-openai/.gitignore
index 704a855f25d4..d186e8809dfc 100644
--- a/examples/next-openai/.gitignore
+++ b/examples/next-openai/.gitignore
@@ -34,5 +34,6 @@ yarn-error.log*
 *.tsbuildinfo
 next-env.d.ts
 
-# chat persistence
+# persistence
 .chats
+.streams
diff --git a/examples/next-openai/app/api/use-chat-resume/route.ts b/examples/next-openai/app/api/use-chat-resume/route.ts
new file mode 100644
index 000000000000..0afbf26f9557
--- /dev/null
+++ b/examples/next-openai/app/api/use-chat-resume/route.ts
@@ -0,0 +1,102 @@
+import {
+  appendMessageToChat,
+  appendStreamId,
+  createChat,
+  loadStreams,
+  saveChat,
+} from '@/util/chat-store';
+import { openai } from '@ai-sdk/openai';
+import {
+  appendResponseMessages,
+  createDataStream,
+  generateId,
+  Message,
+  streamText,
+} from 'ai';
+import { after } from 'next/server';
+import { createResumableStreamContext } from 'resumable-stream';
+
+// Allow streaming responses up to 30 seconds
+export const maxDuration = 30;
+
+const redisUrl = process.env.KV_URL;
+
+if (!redisUrl) {
+  throw new Error('KV_URL environment variable is not set');
+}
+
+const streamContext = createResumableStreamContext({
+  waitUntil: after,
+});
+
+export async function POST(req: Request) {
+  const { id, messages }: { id: string; messages: Message[] } =
+    await req.json();
+
+  const streamId = generateId();
+
+  const recentUserMessage = messages
+    .filter(message => message.role === 'user')
+    .at(-1);
+
+  if (!recentUserMessage) {
+    throw new Error('No recent user message found');
+  }
+
+  await appendMessageToChat({ chatId: id, message: recentUserMessage });
+
+  await appendStreamId({ chatId: id, streamId });
+
+  const stream = createDataStream({
+    execute: dataStream => {
+      const result = streamText({
+        model: openai('gpt-4o'),
+        messages,
+        onFinish: async ({ response }) => {
+          await saveChat({
+            id,
+            messages: appendResponseMessages({
+              messages,
+              responseMessages: response.messages,
+            }),
+          });
+        },
+      });
+
+      result.mergeIntoDataStream(dataStream);
+    },
+  });
+
+  return new Response(
+    await streamContext.resumableStream(streamId, () => stream),
+  );
+}
+
+export async function GET(request: Request) {
+  const { searchParams } = new URL(request.url);
+  const chatId = searchParams.get('chatId');
+
+  if (!chatId) {
+    return new Response('id is required', { status: 400 });
+  }
+
+  const streamIds = await loadStreams(chatId);
+
+  if (!streamIds.length) {
+    return new Response('No streams found', { status: 404 });
+  }
+
+  const recentStreamId = streamIds.at(-1);
+
+  if (!recentStreamId) {
+    return new Response('No recent stream found', { status: 404 });
+  }
+
+  const emptyDataStream = createDataStream({
+    execute: () => {},
+  });
+
+  return new Response(
+    await streamContext.resumableStream(recentStreamId, () => emptyDataStream),
+  );
+}
diff --git a/examples/next-openai/app/use-chat-resume/[id]/page.tsx b/examples/next-openai/app/use-chat-resume/[id]/page.tsx
new file mode 100644
index 000000000000..85ac133795d7
--- /dev/null
+++ b/examples/next-openai/app/use-chat-resume/[id]/page.tsx
@@ -0,0 +1,14 @@
+import { loadChat } from '@/util/chat-store';
+import { Chat } from '../chat';
+
+export default async function Page({
+  params,
+}: {
+  params: Promise<{ id: string }>;
+}) {
+  const { id } = await params;
+
+  const messages = await loadChat(id);
+
+  return <Chat chatId={id} autoResume={true} initialMessages={messages} />;
+}
diff --git a/examples/next-openai/app/use-chat-resume/chat.tsx b/examples/next-openai/app/use-chat-resume/chat.tsx
new file mode 100644
index 000000000000..e920eae6c807
--- /dev/null
+++ b/examples/next-openai/app/use-chat-resume/chat.tsx
@@ -0,0 +1,109 @@
+'use client';
+
+import { useChat } from '@ai-sdk/react';
+import { Message } from 'ai';
+import Link from 'next/link';
+import { useEffect } from 'react';
+
+export function Chat({
+  chatId,
+  autoResume,
+  initialMessages = [],
+}: {
+  chatId: string;
+  autoResume: boolean;
+  initialMessages: Message[];
+}) {
+  const {
+    error,
+    input,
+    status,
+    handleInputChange,
+    handleSubmit,
+    messages,
+    reload,
+    stop,
+    experimental_resume,
+  } = useChat({
+    id: chatId,
+    api: '/api/use-chat-resume',
+    initialMessages,
+    sendExtraMessageFields: true,
+    onError: error => {
+      console.error('Error streaming text:', error);
+    },
+  });
+
+  useEffect(() => {
+    if (autoResume) {
+      experimental_resume();
+    }
+  }, []);
+
+  return (
+    <div className="flex flex-col w-full max-w-md py-24 mx-auto stretch gap-8">
+      <Link href={`/use-chat-resume/${chatId}`} target="_noblank">
+        Chat Id: {chatId}
+      </Link>
+
+      <div>Status: {status}</div>
+
+      {messages.map(message => (
+        <div key={message.id} className="whitespace-pre-wrap flex flex-row">
+          <div className="min-w-12">
+            {message.role === 'user' ? 'User: ' : 'AI: '}
+          </div>
+
+          <div>
+            <div className="text-sm text-zinc-500">{message.id}</div>
+            {message.parts
+              .filter(part => part.type !== 'source')
+              .map((part, partIndex) => {
+                if (part.type === 'text') {
+                  return (
+                    <div key={`${message.id}-${partIndex}`}>{part.text}</div>
+                  );
+                }
+              })}
+          </div>
+        </div>
+      ))}
+
+      {(status === 'submitted' || status === 'streaming') && (
+        <div className="mt-4 text-gray-500">
+          {status === 'submitted' && <div>Loading...</div>}
+          <button
+            type="button"
+            className="px-4 py-2 mt-4 text-blue-500 border border-blue-500 rounded-md"
+            onClick={stop}
+          >
+            Stop
+          </button>
+        </div>
+      )}
+
+      {error && (
+        <div className="mt-4">
+          <div className="text-red-500">An error occurred.</div>
+          <button
+            type="button"
+            className="px-4 py-2 mt-4 text-blue-500 border border-blue-500 rounded-md"
+            onClick={() => reload()}
+          >
+            Retry
+          </button>
+        </div>
+      )}
+
+      <form onSubmit={handleSubmit}>
+        <input
+          className="fixed bottom-0 w-full max-w-md p-2 mb-8 border border-gray-300 rounded shadow-xl"
+          value={input}
+          placeholder="Say something..."
+          onChange={handleInputChange}
+          disabled={status !== 'ready'}
+        />
+      </form>
+    </div>
+  );
+}
diff --git a/examples/next-openai/app/use-chat-resume/page.tsx b/examples/next-openai/app/use-chat-resume/page.tsx
new file mode 100644
index 000000000000..dc60255f6769
--- /dev/null
+++ b/examples/next-openai/app/use-chat-resume/page.tsx
@@ -0,0 +1,8 @@
+import { Chat } from './chat';
+import { generateId } from 'ai';
+
+export default function Page() {
+  const chatId = generateId(32);
+
+  return <Chat chatId={chatId} autoResume={false} initialMessages={[]} />;
+}
diff --git a/examples/next-openai/package.json b/examples/next-openai/package.json
index a673f7596fb4..792620118761 100644
--- a/examples/next-openai/package.json
+++ b/examples/next-openai/package.json
@@ -10,14 +10,22 @@
   },
   "dependencies": {
     "@ai-sdk/anthropic": "1.2.10",
+<<<<<<< Updated upstream
     "@ai-sdk/deepseek": "0.2.13",
     "@ai-sdk/fireworks": "0.2.13",
     "@ai-sdk/openai": "1.3.19",
     "@ai-sdk/google": "1.2.13",
     "@ai-sdk/google-vertex": "2.2.17",
+=======
+    "@ai-sdk/deepseek": "0.2.12",
+    "@ai-sdk/fireworks": "0.2.12",
+    "@ai-sdk/google": "1.2.12",
+    "@ai-sdk/google-vertex": "2.2.16",
+    "@ai-sdk/openai": "1.3.16",
+>>>>>>> Stashed changes
     "@ai-sdk/perplexity": "1.1.7",
-    "@ai-sdk/ui-utils": "1.2.8",
     "@ai-sdk/react": "1.2.9",
+    "@ai-sdk/ui-utils": "1.2.8",
     "@vercel/blob": "^0.26.0",
     "ai": "4.3.10",
     "next": "latest",
@@ -25,6 +33,8 @@
     "react": "^18",
     "react-dom": "^18",
     "react-markdown": "9.0.1",
+    "redis": "^4.7.0",
+    "resumable-stream": "^2.0.0",
     "zod": "3.23.8"
   },
   "devDependencies": {
diff --git a/examples/next-openai/util/chat-store.ts b/examples/next-openai/util/chat-store.ts
index 6f58a23edcba..319ab3e299c4 100644
--- a/examples/next-openai/util/chat-store.ts
+++ b/examples/next-openai/util/chat-store.ts
@@ -1,5 +1,5 @@
 import { generateId, Message } from 'ai';
-import { existsSync, mkdirSync } from 'fs';
+import { existsSync, mkdirSync, writeFileSync } from 'fs';
 import { readFile, writeFile } from 'fs/promises';
 import path from 'path';
 
@@ -23,12 +23,58 @@ export async function saveChat({
   await writeFile(getChatFile(id), JSON.stringify(messages, null, 2));
 }
 
+export async function appendMessageToChat({
+  chatId,
+  message,
+}: {
+  chatId: string;
+  message: Message;
+}): Promise<void> {
+  const file = getChatFile(chatId);
+  const messages = await loadChat(chatId);
+  messages.push(message);
+  await writeFile(file, JSON.stringify(messages, null, 2));
+}
+
 export async function loadChat(id: string): Promise<Message[]> {
   return JSON.parse(await readFile(getChatFile(id), 'utf8'));
 }
 
 function getChatFile(id: string): string {
   const chatDir = path.join(process.cwd(), '.chats');
+
+  if (!existsSync(chatDir)) mkdirSync(chatDir, { recursive: true });
+
+  const chatFile = path.join(chatDir, `${id}.json`);
+
+  if (!existsSync(chatFile)) {
+    writeFileSync(chatFile, '[]');
+  }
+
+  return chatFile;
+}
+
+export async function appendStreamId({
+  chatId,
+  streamId,
+}: {
+  chatId: string;
+  streamId: string;
+}) {
+  const file = getStreamsFile(chatId);
+  const streams = await loadStreams(chatId);
+  streams.push(streamId);
+  await writeFile(file, JSON.stringify(streams, null, 2));
+}
+
+export async function loadStreams(chatId: string): Promise<string[]> {
+  const file = getStreamsFile(chatId);
+  if (!existsSync(file)) return [];
+  return JSON.parse(await readFile(file, 'utf8'));
+}
+
+function getStreamsFile(chatId: string): string {
+  const chatDir = path.join(process.cwd(), '.streams');
   if (!existsSync(chatDir)) mkdirSync(chatDir, { recursive: true });
-  return path.join(chatDir, `${id}.json`);
+  return path.join(chatDir, `${chatId}.json`);
 }
diff --git a/packages/react/src/use-chat.ts b/packages/react/src/use-chat.ts
index 86b0720fbf86..ef0bda759d84 100644
--- a/packages/react/src/use-chat.ts
+++ b/packages/react/src/use-chat.ts
@@ -9,6 +9,7 @@ import type {
 } from '@ai-sdk/ui-utils';
 import {
   callChatApi,
+  resumeChatApi,
   extractMaxToolInvocationStep,
   fillMessageParts,
   generateId as generateIdFunc,
@@ -52,6 +53,12 @@ export type UseChatHelpers = {
    * Abort the current request immediately, keep the generated tokens if any.
    */
   stop: () => void;
+
+  /**
+   * Resume an ongoing chat generation stream. This does not resume an aborted generation.
+   */
+  experimental_resume: () => Promise<string | null | undefined>;
+
   /**
    * Update the `messages` state locally. This is useful when you want to
    * edit the messages on the client, and then trigger the `reload` method
@@ -400,6 +407,100 @@ By default, it's set to 1, which means that only a single LLM call is made.
     ],
   );
 
+  const triggerResumeRequest = useCallback(async () => {
+    const body = {
+      id: chatId,
+      messages: messagesRef.current,
+    };
+
+    try {
+      const abortController = new AbortController();
+      abortControllerRef.current = abortController;
+
+      const throttledMutate = throttle(mutate, throttleWaitMs);
+      const throttledMutateStreamData = throttle(
+        mutateStreamData,
+        throttleWaitMs,
+      );
+
+      const previousMessages = messagesRef.current;
+      const chatMessages = fillMessageParts(previousMessages);
+
+      const existingData = streamDataRef.current;
+
+      await resumeChatApi({
+        api,
+        body,
+        fetch,
+        onResponse,
+        restoreMessagesOnFailure() {
+          if (!keepLastMessageOnError) {
+            throttledMutate(previousMessages, false);
+          }
+        },
+        streamProtocol,
+        onUpdate({ message, data, replaceLastMessage }) {
+          mutateStatus('streaming');
+
+          throttledMutate(
+            [
+              ...(replaceLastMessage
+                ? chatMessages.slice(0, chatMessages.length - 1)
+                : chatMessages),
+              message,
+            ],
+            false,
+          );
+
+          if (data?.length) {
+            throttledMutateStreamData(
+              [...(existingData ?? []), ...data],
+              false,
+            );
+          }
+        },
+        onFinish,
+        onToolCall,
+        generateId,
+        lastMessage: chatMessages[chatMessages.length - 1],
+      });
+
+      abortControllerRef.current = null;
+
+      mutateStatus('ready');
+    } catch (error) {
+      // Ignore abort errors as they are expected.
+      if ((error as any).name === 'AbortError') {
+        abortControllerRef.current = null;
+        mutateStatus('ready');
+        return null;
+      }
+
+      if (onError && error instanceof Error) {
+        onError(error);
+      }
+
+      setError(error as Error);
+      mutateStatus('error');
+    }
+  }, [
+    api,
+    chatId,
+    fetch,
+    generateId,
+    keepLastMessageOnError,
+    mutate,
+    mutateStatus,
+    mutateStreamData,
+    onFinish,
+    onResponse,
+    onToolCall,
+    streamProtocol,
+    throttleWaitMs,
+    onError,
+    setError,
+  ]);
+
   const append = useCallback(
     async (
       message: Message | CreateMessage,
@@ -456,6 +557,10 @@ By default, it's set to 1, which means that only a single LLM call is made.
     }
   }, []);
 
+  const experimental_resume = useCallback(async () => {
+    return triggerResumeRequest();
+  }, [triggerResumeRequest]);
+
   const setMessages = useCallback(
     (messages: Message[] | ((messages: Message[]) => Message[])) => {
       if (typeof messages === 'function') {
@@ -581,6 +686,7 @@ By default, it's set to 1, which means that only a single LLM call is made.
     append,
     reload,
     stop,
+    experimental_resume,
     input,
     setInput,
     handleInputChange,
diff --git a/packages/react/src/use-chat.ui.test.tsx b/packages/react/src/use-chat.ui.test.tsx
index 60823b960082..3b9413c75bc2 100644
--- a/packages/react/src/use-chat.ui.test.tsx
+++ b/packages/react/src/use-chat.ui.test.tsx
@@ -1855,3 +1855,53 @@ describe('initialMessages', () => {
     });
   });
 });
+
+describe('resume ongoing stream and return assistant message', () => {
+  setupTestComponent(
+    () => {
+      const { messages, status, experimental_resume } = useChat({
+        id: '123',
+        initialMessages: [{ id: 'msg_123', role: 'user', content: 'hi' }],
+      });
+
+      useEffect(() => {
+        experimental_resume();
+      }, []);
+
+      return (
+        <div>
+          {messages.map((m, idx) => (
+            <div data-testid={`message-${idx}`} key={m.id}>
+              {m.role === 'user' ? 'User: ' : 'AI: '}
+              {m.content}
+            </div>
+          ))}
+
+          <div data-testid="status">{status}</div>
+        </div>
+      );
+    },
+    {
+      init: TestComponent => {
+        server.urls['/api/chat'].response = [
+          {
+            type: 'stream-chunks',
+            chunks: ['0:"Hello"\n', '0:"," \n', '0:" world"\n', '0:"."\n'],
+          },
+        ];
+
+        return <TestComponent />;
+      },
+    },
+  );
+
+  it('construct messages from resumed stream', async () => {
+    await screen.findByTestId('message-0');
+    expect(screen.getByTestId('message-0')).toHaveTextContent('User: hi');
+
+    await screen.findByTestId('message-1');
+    expect(screen.getByTestId('message-1')).toHaveTextContent(
+      'AI: Hello, world.',
+    );
+  });
+});
diff --git a/packages/ui-utils/src/call-chat-api.ts b/packages/ui-utils/src/call-chat-api.ts
index 80fc1636f8eb..188f62540e77 100644
--- a/packages/ui-utils/src/call-chat-api.ts
+++ b/packages/ui-utils/src/call-chat-api.ts
@@ -106,3 +106,91 @@ export async function callChatApi({
     }
   }
 }
+
+export async function resumeChatApi({
+  api,
+  body,
+  fetch = getOriginalFetch(),
+  onResponse,
+  restoreMessagesOnFailure,
+  streamProtocol = 'data',
+  onUpdate,
+  onFinish,
+  onToolCall,
+  generateId,
+  lastMessage,
+}: {
+  api: string;
+  body: Record<string, any>;
+  fetch: ReturnType<typeof getOriginalFetch> | undefined;
+  onResponse: ((response: Response) => void | Promise<void>) | undefined;
+  restoreMessagesOnFailure: () => void;
+  streamProtocol: 'data' | 'text' | undefined;
+  onUpdate: (options: {
+    message: UIMessage;
+    data: JSONValue[] | undefined;
+    replaceLastMessage: boolean;
+  }) => void;
+  onFinish: UseChatOptions['onFinish'];
+  onToolCall: UseChatOptions['onToolCall'];
+  generateId: IdGenerator;
+  lastMessage: UIMessage | undefined;
+}) {
+  const { id } = body;
+
+  const response = await fetch(`${api}?chatId=${id}`, {
+    method: 'GET',
+  });
+
+  if (onResponse) {
+    try {
+      await onResponse(response);
+    } catch (err) {
+      throw err;
+    }
+  }
+
+  if (!response.ok) {
+    restoreMessagesOnFailure();
+    throw new Error(
+      (await response.text()) ?? 'Failed to fetch the chat response.',
+    );
+  }
+
+  if (!response.body) {
+    throw new Error('The response body is empty.');
+  }
+
+  switch (streamProtocol) {
+    case 'text': {
+      await processChatTextResponse({
+        stream: response.body,
+        update: onUpdate,
+        onFinish,
+        generateId,
+      });
+      return;
+    }
+
+    case 'data': {
+      await processChatResponse({
+        stream: response.body,
+        update: onUpdate,
+        lastMessage,
+        onToolCall,
+        onFinish({ message, finishReason, usage }) {
+          if (onFinish && message != null) {
+            onFinish(message, { usage, finishReason });
+          }
+        },
+        generateId,
+      });
+      return;
+    }
+
+    default: {
+      const exhaustiveCheck: never = streamProtocol;
+      throw new Error(`Unknown stream protocol: ${exhaustiveCheck}`);
+    }
+  }
+}
diff --git a/packages/ui-utils/src/index.ts b/packages/ui-utils/src/index.ts
index 12ba2071ccb6..de388ff3cdf3 100644
--- a/packages/ui-utils/src/index.ts
+++ b/packages/ui-utils/src/index.ts
@@ -13,7 +13,7 @@ export type {
   AssistantStreamPart,
   AssistantStreamString,
 } from './assistant-stream-parts';
-export { callChatApi } from './call-chat-api';
+export { callChatApi, resumeChatApi } from './call-chat-api';
 export { callCompletionApi } from './call-completion-api';
 export { formatDataStreamPart, parseDataStreamPart } from './data-stream-parts';
 export type { DataStreamPart, DataStreamString } from './data-stream-parts';
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index bfabe5a8e274..0bfa34f793b7 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -343,7 +343,7 @@ importers:
         version: 10.2.3(chokidar@3.6.0)(typescript@5.5.4)
       '@nestjs/testing':
         specifier: ^10.4.12
-        version: 10.4.12(@nestjs/common@10.4.15(reflect-metadata@0.2.2)(rxjs@7.8.1))(@nestjs/core@10.4.2)(@nestjs/platform-express@10.4.9)
+        version: 10.4.12(@nestjs/common@10.4.15(reflect-metadata@0.2.2)(rxjs@7.8.1))(@nestjs/core@10.4.2(@nestjs/common@10.4.15(reflect-metadata@0.2.2)(rxjs@7.8.1))(@nestjs/platform-express@10.4.9)(reflect-metadata@0.2.2)(rxjs@7.8.1))(@nestjs/platform-express@10.4.9(@nestjs/common@10.4.15(reflect-metadata@0.2.2)(rxjs@7.8.1))(@nestjs/core@10.4.2))
       '@types/express':
         specifier: ^5.0.0
         version: 5.0.0
@@ -513,7 +513,7 @@ importers:
         version: link:../../packages/ai
       langchain:
         specifier: 0.1.36
-        version: 0.1.36(@aws-crypto/sha256-js@5.2.0)(@aws-sdk/client-bedrock-runtime@3.663.0)(@aws-sdk/credential-provider-node@3.662.0(@aws-sdk/client-sso-oidc@3.662.0(@aws-sdk/client-sts@3.662.0))(@aws-sdk/client-sts@3.662.0))(@smithy/util-utf8@2.3.0)(@upstash/redis@1.34.3)(@vercel/kv@0.2.4)(fast-xml-parser@4.4.1)(ignore@5.3.2)(ioredis@5.4.1)(jsdom@26.0.0)(lodash@4.17.21)(openai@4.52.6)(playwright@1.50.1)(ws@8.18.0)
+        version: 0.1.36(@aws-crypto/sha256-js@5.2.0)(@aws-sdk/client-bedrock-runtime@3.663.0)(@aws-sdk/credential-provider-node@3.662.0)(@smithy/util-utf8@2.3.0)(@upstash/redis@1.34.3)(@vercel/kv@0.2.4)(fast-xml-parser@4.4.1)(ignore@5.3.2)(ioredis@5.4.1)(jsdom@26.0.0)(lodash@4.17.21)(openai@4.52.6)(playwright@1.50.1)(redis@4.7.0)(ws@8.18.0)
       next:
         specifier: latest
         version: 15.2.2(@opentelemetry/api@1.9.0)(@playwright/test@1.50.1)(react-dom@18.2.0(react@18.2.0))(react@18.2.0)
@@ -602,6 +602,12 @@ importers:
       react-markdown:
         specifier: 9.0.1
         version: 9.0.1(@types/react@18.3.3)(react@18.3.1)
+      redis:
+        specifier: ^4.7.0
+        version: 4.7.0
+      resumable-stream:
+        specifier: ^2.0.0
+        version: 2.0.0
       zod:
         specifier: 3.23.8
         version: 3.23.8
@@ -644,7 +650,7 @@ importers:
         version: link:../../packages/react
       '@vercel/functions':
         specifier: latest
-        version: 2.0.0(@aws-sdk/credential-provider-web-identity@3.662.0(@aws-sdk/client-sts@3.662.0))
+        version: 2.0.0(@aws-sdk/credential-provider-web-identity@3.662.0)
       ai:
         specifier: 4.3.10
         version: link:../../packages/ai
@@ -1011,7 +1017,7 @@ importers:
         version: 3.5.12
       nuxt:
         specifier: 3.14.159
-        version: 3.14.159(@parcel/watcher@2.4.1)(@types/node@20.17.24)(@upstash/redis@1.34.3)(eslint@9.21.0(jiti@2.4.0))(ioredis@5.4.1)(magicast@0.3.5)(optionator@0.9.4)(rollup@4.34.9)(terser@5.31.3)(typescript@5.6.3)(vite@5.4.11(@types/node@20.17.24)(terser@5.31.3))(webpack-sources@3.2.3)
+        version: 3.14.159(@parcel/watcher@2.4.1)(@types/node@20.17.24)(@upstash/redis@1.34.3)(eslint@9.21.0)(ioredis@5.4.1)(magicast@0.3.5)(optionator@0.9.4)(rollup@4.34.9)(terser@5.31.3)(typescript@5.6.3)(vite@5.4.11(@types/node@20.17.24)(terser@5.31.3))(webpack-sources@3.2.3)
       tailwindcss:
         specifier: 3.4.15
         version: 3.4.15(ts-node@10.9.2(@types/node@20.17.24)(typescript@5.6.3))
@@ -2090,7 +2096,7 @@ importers:
         version: link:../../tools/tsconfig
       '@vitejs/plugin-vue':
         specifier: 5.2.0
-        version: 5.2.0(vite@5.4.11(@types/node@20.17.24)(terser@5.31.3))(vue@3.5.13(typescript@5.6.3))
+        version: 5.2.0(vite@5.4.11(@types/node@22.7.4)(terser@5.31.3))(vue@3.5.13(typescript@5.6.3))
       eslint:
         specifier: 8.57.1
         version: 8.57.1
@@ -2111,7 +2117,7 @@ importers:
         version: 5.6.3
       vite-plugin-solid:
         specifier: 2.7.2
-        version: 2.7.2(solid-js@1.8.7)
+        version: 2.7.2(solid-js@1.8.7)(vite@5.4.11(@types/node@22.7.4)(terser@5.31.3))
       vitest:
         specifier: 2.1.4
         version: 2.1.4(@edge-runtime/vm@5.0.0)(@types/node@20.17.24)(jsdom@24.0.0)(msw@2.6.4(@types/node@20.17.24)(typescript@5.6.3))(terser@5.31.3)
@@ -6441,6 +6447,35 @@ packages:
     resolution: {integrity: sha512-S+9ANAvUmjutrshV4jZjaiG8XQyuJIZ8a4utWmN/vW1sgQ9IfBnPndwkmQYw53QmouOIytT874u65HEmu6H5jw==}
     engines: {node: '>=18'}
 
+  '@redis/bloom@1.2.0':
+    resolution: {integrity: sha512-HG2DFjYKbpNmVXsa0keLHp/3leGJz1mjh09f2RLGGLQZzSHpkmZWuwJbAvo3QcRY8p80m5+ZdXZdYOSBLlp7Cg==}
+    peerDependencies:
+      '@redis/client': ^1.0.0
+
+  '@redis/client@1.6.0':
+    resolution: {integrity: sha512-aR0uffYI700OEEH4gYnitAnv3vzVGXCFvYfdpu/CJKvk4pHfLPEy/JSZyrpQ+15WhXe1yJRXLtfQ84s4mEXnPg==}
+    engines: {node: '>=14'}
+
+  '@redis/graph@1.1.1':
+    resolution: {integrity: sha512-FEMTcTHZozZciLRl6GiiIB4zGm5z5F3F6a6FZCyrfxdKOhFlGkiAqlexWMBzCi4DcRoyiOsuLfW+cjlGWyExOw==}
+    peerDependencies:
+      '@redis/client': ^1.0.0
+
+  '@redis/json@1.0.7':
+    resolution: {integrity: sha512-6UyXfjVaTBTJtKNG4/9Z8PSpKE6XgSyEb8iwaqDcy+uKrd/DGYHTWkUdnQDyzm727V7p21WUMhsqz5oy65kPcQ==}
+    peerDependencies:
+      '@redis/client': ^1.0.0
+
+  '@redis/search@1.2.0':
+    resolution: {integrity: sha512-tYoDBbtqOVigEDMAcTGsRlMycIIjwMCgD8eR2t0NANeQmgK/lvxNAvYyb6bZDD4frHRhIHkJu2TBRvB0ERkOmw==}
+    peerDependencies:
+      '@redis/client': ^1.0.0
+
+  '@redis/time-series@1.1.0':
+    resolution: {integrity: sha512-c1Q99M5ljsIuc4YdaCwfUEXsofakb9c8+Zse2qxTadu8TalLXuAESzLvFAvNVbkmSlvlzIQOLpBCmWI9wTOt+g==}
+    peerDependencies:
+      '@redis/client': ^1.0.0
+
   '@redocly/ajv@8.11.2':
     resolution: {integrity: sha512-io1JpnwtIcvojV7QKDUSIuMN/ikdOUd1ReEnUnMKGfDVridQZ31J0MmIuqwuRjWDZfmvr+Q0MqCcfHM2gTivOg==}
 
@@ -10213,6 +10248,10 @@ packages:
     peerDependencies:
       next: '>=13.2.0'
 
+  generic-pool@3.9.0:
+    resolution: {integrity: sha512-hymDOu5B53XvN4QT9dBmZxPX4CWhBPPLguTZ9MMFeFa/Kg0xWVfylOVNlJji/E7yTZWFd/q9GO5TxDLq156D7g==}
+    engines: {node: '>= 4'}
+
   gensync@1.0.0-beta.2:
     resolution: {integrity: sha512-3hN7NaskYvMDLQY55gnW3NQ+mesEAepTqlg+VEbj7zzqEMBVNhzcGYYeqFo/TlYz6eQiFcp1HcsCZO+nGgS8zg==}
     engines: {node: '>=6.9.0'}
@@ -13270,6 +13309,9 @@ packages:
     resolution: {integrity: sha512-DJnGAeenTdpMEH6uAJRK/uiyEIH9WVsUmoLwzudwGJUwZPp80PDBWPHXSAGNPwNvIXAbe7MSUB1zQFugFml66A==}
     engines: {node: '>=4'}
 
+  redis@4.7.0:
+    resolution: {integrity: sha512-zvmkHEAdGMn+hMRXuMBtu4Vo5P6rHQjLoHftu+lBqq8ZTA3RCVC/WzD790bkKKiNFp7d5/9PcSD19fJyyRvOdQ==}
+
   reflect-metadata@0.2.2:
     resolution: {integrity: sha512-urBwgfrvVP/eAyXx4hluJivBKzuEbSQs9rKWCrCkbSxNv8mxPcUZKeuoF3Uy4mJl3Lwprp6yy5/39VWigZ4K6Q==}
 
@@ -13360,6 +13402,9 @@ packages:
     resolution: {integrity: sha512-oMA2dcrw6u0YfxJQXm342bFKX/E4sG9rbTzO9ptUcR/e8A33cHuvStiYOwH7fszkZlZ1z/ta9AAoPk2F4qIOHA==}
     engines: {node: '>=18'}
 
+  resumable-stream@2.0.0:
+    resolution: {integrity: sha512-D7E0wDUnfoy+Lerba/gyuD44OG3G0APqDcQ9soMSerujaVujPLWc5sSCLXf/ZFQPreLb3MKDjSm3TOPXpNtpZw==}
+
   ret@0.5.0:
     resolution: {integrity: sha512-I1XxrZSQ+oErkRR4jYbAyEEu2I0avBvvMM5JN+6EBprOGRCs63ENqZ3vjavq8fBw2+62G5LF5XelKwuJpcvcxw==}
     engines: {node: '>=10'}
@@ -17120,6 +17165,12 @@ snapshots:
       eslint: 9.21.0(jiti@2.4.0)
       eslint-visitor-keys: 3.4.3
 
+  '@eslint-community/eslint-utils@4.4.1(eslint@9.21.0)':
+    dependencies:
+      eslint: 9.21.0
+      eslint-visitor-keys: 3.4.3
+    optional: true
+
   '@eslint-community/regexpp@4.11.0': {}
 
   '@eslint-community/regexpp@4.12.1': {}
@@ -18119,7 +18170,7 @@ snapshots:
 
   '@kwsites/promise-deferred@1.1.1': {}
 
-  '@langchain/community@0.0.57(@aws-crypto/sha256-js@5.2.0)(@aws-sdk/client-bedrock-runtime@3.663.0)(@aws-sdk/credential-provider-node@3.662.0(@aws-sdk/client-sso-oidc@3.662.0(@aws-sdk/client-sts@3.662.0))(@aws-sdk/client-sts@3.662.0))(@smithy/util-utf8@2.3.0)(@upstash/redis@1.34.3)(@vercel/kv@0.2.4)(ioredis@5.4.1)(jsdom@26.0.0)(lodash@4.17.21)(openai@4.52.6)(ws@8.18.0)':
+  '@langchain/community@0.0.57(@aws-crypto/sha256-js@5.2.0)(@aws-sdk/client-bedrock-runtime@3.663.0)(@aws-sdk/credential-provider-node@3.662.0)(@smithy/util-utf8@2.3.0)(@upstash/redis@1.34.3)(@vercel/kv@0.2.4)(ioredis@5.4.1)(jsdom@26.0.0)(lodash@4.17.21)(openai@4.52.6)(redis@4.7.0)(ws@8.18.0)':
     dependencies:
       '@langchain/core': 0.1.63(openai@4.52.6)
       '@langchain/openai': 0.0.28
@@ -18139,6 +18190,7 @@ snapshots:
       ioredis: 5.4.1
       jsdom: 26.0.0
       lodash: 4.17.21
+      redis: 4.7.0
       ws: 8.18.0
     transitivePeerDependencies:
       - encoding
@@ -18361,7 +18413,7 @@ snapshots:
     transitivePeerDependencies:
       - chokidar
 
-  '@nestjs/testing@10.4.12(@nestjs/common@10.4.15(reflect-metadata@0.2.2)(rxjs@7.8.1))(@nestjs/core@10.4.2)(@nestjs/platform-express@10.4.9)':
+  '@nestjs/testing@10.4.12(@nestjs/common@10.4.15(reflect-metadata@0.2.2)(rxjs@7.8.1))(@nestjs/core@10.4.2(@nestjs/common@10.4.15(reflect-metadata@0.2.2)(rxjs@7.8.1))(@nestjs/platform-express@10.4.9)(reflect-metadata@0.2.2)(rxjs@7.8.1))(@nestjs/platform-express@10.4.9(@nestjs/common@10.4.15(reflect-metadata@0.2.2)(rxjs@7.8.1))(@nestjs/core@10.4.2))':
     dependencies:
       '@nestjs/common': 10.4.15(reflect-metadata@0.2.2)(rxjs@7.8.1)
       '@nestjs/core': 10.4.2(@nestjs/common@10.4.15(reflect-metadata@0.2.2)(rxjs@7.8.1))(@nestjs/platform-express@10.4.9)(reflect-metadata@0.2.2)(rxjs@7.8.1)
@@ -18671,7 +18723,7 @@ snapshots:
 
   '@nuxt/ui-templates@1.3.4': {}
 
-  '@nuxt/vite-builder@3.14.159(@types/node@20.17.24)(eslint@9.21.0(jiti@2.4.0))(magicast@0.3.5)(optionator@0.9.4)(rollup@4.34.9)(terser@5.31.3)(typescript@5.6.3)(vue@3.5.13(typescript@5.6.3))(webpack-sources@3.2.3)':
+  '@nuxt/vite-builder@3.14.159(@types/node@20.17.24)(eslint@9.21.0)(magicast@0.3.5)(optionator@0.9.4)(rollup@4.34.9)(terser@5.31.3)(typescript@5.6.3)(vue@3.5.13(typescript@5.6.3))(webpack-sources@3.2.3)':
     dependencies:
       '@nuxt/kit': 3.14.159(magicast@0.3.5)(rollup@4.34.9)
       '@rollup/plugin-replace': 6.0.1(rollup@4.34.9)
@@ -18705,7 +18757,7 @@ snapshots:
       unplugin: 1.15.0(webpack-sources@3.2.3)
       vite: 5.4.11(@types/node@20.17.24)(terser@5.31.3)
       vite-node: 2.1.4(@types/node@20.17.24)(terser@5.31.3)
-      vite-plugin-checker: 0.8.0(eslint@9.21.0(jiti@2.4.0))(optionator@0.9.4)(typescript@5.6.3)(vite@5.4.11(@types/node@20.17.24)(terser@5.31.3))
+      vite-plugin-checker: 0.8.0(eslint@9.21.0)(optionator@0.9.4)(typescript@5.6.3)(vite@5.4.11(@types/node@20.17.24)(terser@5.31.3))
       vue: 3.5.13(typescript@5.6.3)
       vue-bundle-renderer: 2.1.1
     transitivePeerDependencies:
@@ -19993,6 +20045,32 @@ snapshots:
 
   '@publint/pack@0.1.2': {}
 
+  '@redis/bloom@1.2.0(@redis/client@1.6.0)':
+    dependencies:
+      '@redis/client': 1.6.0
+
+  '@redis/client@1.6.0':
+    dependencies:
+      cluster-key-slot: 1.1.2
+      generic-pool: 3.9.0
+      yallist: 4.0.0
+
+  '@redis/graph@1.1.1(@redis/client@1.6.0)':
+    dependencies:
+      '@redis/client': 1.6.0
+
+  '@redis/json@1.0.7(@redis/client@1.6.0)':
+    dependencies:
+      '@redis/client': 1.6.0
+
+  '@redis/search@1.2.0(@redis/client@1.6.0)':
+    dependencies:
+      '@redis/client': 1.6.0
+
+  '@redis/time-series@1.1.0(@redis/client@1.6.0)':
+    dependencies:
+      '@redis/client': 1.6.0
+
   '@redocly/ajv@8.11.2':
     dependencies:
       fast-deep-equal: 3.1.3
@@ -21637,7 +21715,7 @@ snapshots:
       throttleit: 2.1.0
       undici: 5.28.4
 
-  '@vercel/functions@2.0.0(@aws-sdk/credential-provider-web-identity@3.662.0(@aws-sdk/client-sts@3.662.0))':
+  '@vercel/functions@2.0.0(@aws-sdk/credential-provider-web-identity@3.662.0)':
     optionalDependencies:
       '@aws-sdk/credential-provider-web-identity': 3.662.0(@aws-sdk/client-sts@3.662.0)
 
@@ -21783,6 +21861,11 @@ snapshots:
       vite: 5.4.11(@types/node@20.17.24)(terser@5.31.3)
       vue: 3.5.13(typescript@5.6.3)
 
+  '@vitejs/plugin-vue@5.2.0(vite@5.4.11(@types/node@22.7.4)(terser@5.31.3))(vue@3.5.13(typescript@5.6.3))':
+    dependencies:
+      vite: 5.4.11(@types/node@22.7.4)(terser@5.31.3)
+      vue: 3.5.13(typescript@5.6.3)
+
   '@vitejs/plugin-vue@5.2.0(vite@6.0.3(@types/node@20.17.24)(jiti@2.4.0)(terser@5.31.3)(tsx@4.19.2)(yaml@2.7.0))(vue@3.3.8(typescript@5.6.3))':
     dependencies:
       vite: 6.0.3(@types/node@20.17.24)(jiti@2.4.0)(terser@5.31.3)(tsx@4.19.2)(yaml@2.7.0)
@@ -24096,7 +24179,7 @@ snapshots:
       debug: 4.4.0(supports-color@9.4.0)
       enhanced-resolve: 5.17.1
       eslint: 8.57.1
-      eslint-module-utils: 2.8.0(@typescript-eslint/parser@7.2.0(eslint@8.57.1)(typescript@5.4.5))(eslint-import-resolver-node@0.3.9)(eslint-import-resolver-typescript@3.6.1)(eslint@8.57.1)
+      eslint-module-utils: 2.8.0(@typescript-eslint/parser@7.2.0(eslint@8.57.1)(typescript@5.4.5))(eslint-import-resolver-node@0.3.9)(eslint-import-resolver-typescript@3.6.1(@typescript-eslint/parser@7.2.0(eslint@8.57.1)(typescript@5.4.5))(eslint-import-resolver-node@0.3.9)(eslint-plugin-import@2.29.1)(eslint@8.57.1))(eslint@8.57.1)
       eslint-plugin-import: 2.29.1(@typescript-eslint/parser@7.2.0(eslint@8.57.1)(typescript@5.4.5))(eslint-import-resolver-typescript@3.6.1)(eslint@8.57.1)
       fast-glob: 3.3.2
       get-tsconfig: 4.7.2
@@ -24130,7 +24213,7 @@ snapshots:
       debug: 4.4.0(supports-color@9.4.0)
       enhanced-resolve: 5.17.1
       eslint: 9.21.0(jiti@2.4.0)
-      eslint-module-utils: 2.8.0(@typescript-eslint/parser@7.2.0(eslint@9.21.0(jiti@2.4.0))(typescript@5.6.3))(eslint-import-resolver-node@0.3.9)(eslint-import-resolver-typescript@3.6.1)(eslint@9.21.0(jiti@2.4.0))
+      eslint-module-utils: 2.8.0(@typescript-eslint/parser@7.2.0(eslint@9.21.0(jiti@2.4.0))(typescript@5.6.3))(eslint-import-resolver-node@0.3.9)(eslint-import-resolver-typescript@3.6.1(@typescript-eslint/parser@7.2.0(eslint@9.21.0(jiti@2.4.0))(typescript@5.6.3))(eslint-import-resolver-node@0.3.9)(eslint-plugin-import@2.29.1)(eslint@9.21.0(jiti@2.4.0)))(eslint@9.21.0(jiti@2.4.0))
       eslint-plugin-import: 2.29.1(@typescript-eslint/parser@7.2.0(eslint@9.21.0(jiti@2.4.0))(typescript@5.6.3))(eslint-import-resolver-typescript@3.6.1)(eslint@9.21.0(jiti@2.4.0))
       fast-glob: 3.3.2
       get-tsconfig: 4.7.2
@@ -24142,7 +24225,7 @@ snapshots:
       - eslint-import-resolver-webpack
       - supports-color
 
-  eslint-module-utils@2.8.0(@typescript-eslint/parser@7.2.0(eslint@8.57.1)(typescript@5.4.5))(eslint-import-resolver-node@0.3.9)(eslint-import-resolver-typescript@3.6.1)(eslint@8.57.1):
+  eslint-module-utils@2.8.0(@typescript-eslint/parser@7.2.0(eslint@8.57.1)(typescript@5.4.5))(eslint-import-resolver-node@0.3.9)(eslint-import-resolver-typescript@3.6.1(@typescript-eslint/parser@7.2.0(eslint@8.57.1)(typescript@5.4.5))(eslint-import-resolver-node@0.3.9)(eslint-plugin-import@2.29.1)(eslint@8.57.1))(eslint@8.57.1):
     dependencies:
       debug: 3.2.7
     optionalDependencies:
@@ -24164,7 +24247,7 @@ snapshots:
     transitivePeerDependencies:
       - supports-color
 
-  eslint-module-utils@2.8.0(@typescript-eslint/parser@7.2.0(eslint@9.21.0(jiti@2.4.0))(typescript@5.6.3))(eslint-import-resolver-node@0.3.9)(eslint-import-resolver-typescript@3.6.1)(eslint@9.21.0(jiti@2.4.0)):
+  eslint-module-utils@2.8.0(@typescript-eslint/parser@7.2.0(eslint@9.21.0(jiti@2.4.0))(typescript@5.6.3))(eslint-import-resolver-node@0.3.9)(eslint-import-resolver-typescript@3.6.1(@typescript-eslint/parser@7.2.0(eslint@9.21.0(jiti@2.4.0))(typescript@5.6.3))(eslint-import-resolver-node@0.3.9)(eslint-plugin-import@2.29.1)(eslint@9.21.0(jiti@2.4.0)))(eslint@9.21.0(jiti@2.4.0)):
     dependencies:
       debug: 3.2.7
     optionalDependencies:
@@ -24175,7 +24258,7 @@ snapshots:
     transitivePeerDependencies:
       - supports-color
 
-  eslint-module-utils@2.8.1(@typescript-eslint/parser@7.2.0(eslint@8.57.1)(typescript@5.4.5))(eslint-import-resolver-node@0.3.9)(eslint-import-resolver-typescript@3.6.1)(eslint@8.57.1):
+  eslint-module-utils@2.8.1(@typescript-eslint/parser@7.2.0(eslint@8.57.1)(typescript@5.4.5))(eslint-import-resolver-node@0.3.9)(eslint-import-resolver-typescript@3.6.1(@typescript-eslint/parser@7.2.0(eslint@8.57.1)(typescript@5.4.5))(eslint-import-resolver-node@0.3.9)(eslint-plugin-import@2.29.1)(eslint@8.57.1))(eslint@8.57.1):
     dependencies:
       debug: 3.2.7
     optionalDependencies:
@@ -24197,7 +24280,7 @@ snapshots:
     transitivePeerDependencies:
       - supports-color
 
-  eslint-module-utils@2.8.1(@typescript-eslint/parser@7.2.0(eslint@9.21.0(jiti@2.4.0))(typescript@5.6.3))(eslint-import-resolver-node@0.3.9)(eslint-import-resolver-typescript@3.6.1)(eslint@9.21.0(jiti@2.4.0)):
+  eslint-module-utils@2.8.1(@typescript-eslint/parser@7.2.0(eslint@9.21.0(jiti@2.4.0))(typescript@5.6.3))(eslint-import-resolver-node@0.3.9)(eslint-import-resolver-typescript@3.6.1(@typescript-eslint/parser@7.2.0(eslint@9.21.0(jiti@2.4.0))(typescript@5.6.3))(eslint-import-resolver-node@0.3.9)(eslint-plugin-import@2.29.1)(eslint@9.21.0(jiti@2.4.0)))(eslint@9.21.0(jiti@2.4.0)):
     dependencies:
       debug: 3.2.7
     optionalDependencies:
@@ -24218,7 +24301,7 @@ snapshots:
       doctrine: 2.1.0
       eslint: 8.57.1
       eslint-import-resolver-node: 0.3.9
-      eslint-module-utils: 2.8.1(@typescript-eslint/parser@7.2.0(eslint@8.57.1)(typescript@5.4.5))(eslint-import-resolver-node@0.3.9)(eslint-import-resolver-typescript@3.6.1)(eslint@8.57.1)
+      eslint-module-utils: 2.8.1(@typescript-eslint/parser@7.2.0(eslint@8.57.1)(typescript@5.4.5))(eslint-import-resolver-node@0.3.9)(eslint-import-resolver-typescript@3.6.1(@typescript-eslint/parser@7.2.0(eslint@8.57.1)(typescript@5.4.5))(eslint-import-resolver-node@0.3.9)(eslint-plugin-import@2.29.1)(eslint@8.57.1))(eslint@8.57.1)
       hasown: 2.0.2
       is-core-module: 2.15.0
       is-glob: 4.0.3
@@ -24272,7 +24355,7 @@ snapshots:
       doctrine: 2.1.0
       eslint: 9.21.0(jiti@2.4.0)
       eslint-import-resolver-node: 0.3.9
-      eslint-module-utils: 2.8.1(@typescript-eslint/parser@7.2.0(eslint@9.21.0(jiti@2.4.0))(typescript@5.6.3))(eslint-import-resolver-node@0.3.9)(eslint-import-resolver-typescript@3.6.1)(eslint@9.21.0(jiti@2.4.0))
+      eslint-module-utils: 2.8.1(@typescript-eslint/parser@7.2.0(eslint@9.21.0(jiti@2.4.0))(typescript@5.6.3))(eslint-import-resolver-node@0.3.9)(eslint-import-resolver-typescript@3.6.1(@typescript-eslint/parser@7.2.0(eslint@9.21.0(jiti@2.4.0))(typescript@5.6.3))(eslint-import-resolver-node@0.3.9)(eslint-plugin-import@2.29.1)(eslint@9.21.0(jiti@2.4.0)))(eslint@9.21.0(jiti@2.4.0))
       hasown: 2.0.2
       is-core-module: 2.15.0
       is-glob: 4.0.3
@@ -24498,6 +24581,46 @@ snapshots:
     transitivePeerDependencies:
       - supports-color
 
+  eslint@9.21.0:
+    dependencies:
+      '@eslint-community/eslint-utils': 4.4.1(eslint@9.21.0)
+      '@eslint-community/regexpp': 4.12.1
+      '@eslint/config-array': 0.19.2
+      '@eslint/core': 0.12.0
+      '@eslint/eslintrc': 3.3.0
+      '@eslint/js': 9.21.0
+      '@eslint/plugin-kit': 0.2.7
+      '@humanfs/node': 0.16.6
+      '@humanwhocodes/module-importer': 1.0.1
+      '@humanwhocodes/retry': 0.4.2
+      '@types/estree': 1.0.6
+      '@types/json-schema': 7.0.15
+      ajv: 6.12.6
+      chalk: 4.1.2
+      cross-spawn: 7.0.6
+      debug: 4.4.0(supports-color@9.4.0)
+      escape-string-regexp: 4.0.0
+      eslint-scope: 8.2.0
+      eslint-visitor-keys: 4.2.0
+      espree: 10.3.0
+      esquery: 1.6.0
+      esutils: 2.0.3
+      fast-deep-equal: 3.1.3
+      file-entry-cache: 8.0.0
+      find-up: 5.0.0
+      glob-parent: 6.0.2
+      ignore: 5.3.2
+      imurmurhash: 0.1.4
+      is-glob: 4.0.3
+      json-stable-stringify-without-jsonify: 1.0.1
+      lodash.merge: 4.6.2
+      minimatch: 3.1.2
+      natural-compare: 1.4.0
+      optionator: 0.9.4
+    transitivePeerDependencies:
+      - supports-color
+    optional: true
+
   eslint@9.21.0(jiti@2.4.0):
     dependencies:
       '@eslint-community/eslint-utils': 4.4.1(eslint@9.21.0(jiti@2.4.0))
@@ -25099,6 +25222,8 @@ snapshots:
     dependencies:
       next: 15.2.2(@opentelemetry/api@1.9.0)(@playwright/test@1.50.1)(react-dom@18.3.1(react@18.3.1))(react@18.3.1)
 
+  generic-pool@3.9.0: {}
+
   gensync@1.0.0-beta.2: {}
 
   get-caller-file@2.0.5: {}
@@ -26557,10 +26682,10 @@ snapshots:
 
   kolorist@1.8.0: {}
 
-  langchain@0.1.36(@aws-crypto/sha256-js@5.2.0)(@aws-sdk/client-bedrock-runtime@3.663.0)(@aws-sdk/credential-provider-node@3.662.0(@aws-sdk/client-sso-oidc@3.662.0(@aws-sdk/client-sts@3.662.0))(@aws-sdk/client-sts@3.662.0))(@smithy/util-utf8@2.3.0)(@upstash/redis@1.34.3)(@vercel/kv@0.2.4)(fast-xml-parser@4.4.1)(ignore@5.3.2)(ioredis@5.4.1)(jsdom@26.0.0)(lodash@4.17.21)(openai@4.52.6)(playwright@1.50.1)(ws@8.18.0):
+  langchain@0.1.36(@aws-crypto/sha256-js@5.2.0)(@aws-sdk/client-bedrock-runtime@3.663.0)(@aws-sdk/credential-provider-node@3.662.0)(@smithy/util-utf8@2.3.0)(@upstash/redis@1.34.3)(@vercel/kv@0.2.4)(fast-xml-parser@4.4.1)(ignore@5.3.2)(ioredis@5.4.1)(jsdom@26.0.0)(lodash@4.17.21)(openai@4.52.6)(playwright@1.50.1)(redis@4.7.0)(ws@8.18.0):
     dependencies:
       '@anthropic-ai/sdk': 0.9.1
-      '@langchain/community': 0.0.57(@aws-crypto/sha256-js@5.2.0)(@aws-sdk/client-bedrock-runtime@3.663.0)(@aws-sdk/credential-provider-node@3.662.0(@aws-sdk/client-sso-oidc@3.662.0(@aws-sdk/client-sts@3.662.0))(@aws-sdk/client-sts@3.662.0))(@smithy/util-utf8@2.3.0)(@upstash/redis@1.34.3)(@vercel/kv@0.2.4)(ioredis@5.4.1)(jsdom@26.0.0)(lodash@4.17.21)(openai@4.52.6)(ws@8.18.0)
+      '@langchain/community': 0.0.57(@aws-crypto/sha256-js@5.2.0)(@aws-sdk/client-bedrock-runtime@3.663.0)(@aws-sdk/credential-provider-node@3.662.0)(@smithy/util-utf8@2.3.0)(@upstash/redis@1.34.3)(@vercel/kv@0.2.4)(ioredis@5.4.1)(jsdom@26.0.0)(lodash@4.17.21)(openai@4.52.6)(redis@4.7.0)(ws@8.18.0)
       '@langchain/core': 0.1.63(openai@4.52.6)
       '@langchain/openai': 0.0.28
       '@langchain/textsplitters': 0.0.2(openai@4.52.6)
@@ -26585,6 +26710,7 @@ snapshots:
       ioredis: 5.4.1
       jsdom: 26.0.0
       playwright: 1.50.1
+      redis: 4.7.0
       ws: 8.18.0
     transitivePeerDependencies:
       - '@aws-crypto/sha256-js'
@@ -27726,14 +27852,14 @@ snapshots:
 
   nuxi@3.15.0: {}
 
-  nuxt@3.14.159(@parcel/watcher@2.4.1)(@types/node@20.17.24)(@upstash/redis@1.34.3)(eslint@9.21.0(jiti@2.4.0))(ioredis@5.4.1)(magicast@0.3.5)(optionator@0.9.4)(rollup@4.34.9)(terser@5.31.3)(typescript@5.6.3)(vite@5.4.11(@types/node@20.17.24)(terser@5.31.3))(webpack-sources@3.2.3):
+  nuxt@3.14.159(@parcel/watcher@2.4.1)(@types/node@20.17.24)(@upstash/redis@1.34.3)(eslint@9.21.0)(ioredis@5.4.1)(magicast@0.3.5)(optionator@0.9.4)(rollup@4.34.9)(terser@5.31.3)(typescript@5.6.3)(vite@5.4.11(@types/node@20.17.24)(terser@5.31.3))(webpack-sources@3.2.3):
     dependencies:
       '@nuxt/devalue': 2.0.2
       '@nuxt/devtools': 1.6.3(rollup@4.34.9)(vite@5.4.11(@types/node@20.17.24)(terser@5.31.3))(vue@3.5.13(typescript@5.6.3))
       '@nuxt/kit': 3.14.159(magicast@0.3.5)(rollup@4.34.9)
       '@nuxt/schema': 3.14.159(magicast@0.3.5)(rollup@4.34.9)
       '@nuxt/telemetry': 2.6.0(magicast@0.3.5)(rollup@4.34.9)
-      '@nuxt/vite-builder': 3.14.159(@types/node@20.17.24)(eslint@9.21.0(jiti@2.4.0))(magicast@0.3.5)(optionator@0.9.4)(rollup@4.34.9)(terser@5.31.3)(typescript@5.6.3)(vue@3.5.13(typescript@5.6.3))(webpack-sources@3.2.3)
+      '@nuxt/vite-builder': 3.14.159(@types/node@20.17.24)(eslint@9.21.0)(magicast@0.3.5)(optionator@0.9.4)(rollup@4.34.9)(terser@5.31.3)(typescript@5.6.3)(vue@3.5.13(typescript@5.6.3))(webpack-sources@3.2.3)
       '@unhead/dom': 1.11.11
       '@unhead/shared': 1.11.11
       '@unhead/ssr': 1.11.11
@@ -28927,6 +29053,15 @@ snapshots:
     dependencies:
       redis-errors: 1.2.0
 
+  redis@4.7.0:
+    dependencies:
+      '@redis/bloom': 1.2.0(@redis/client@1.6.0)
+      '@redis/client': 1.6.0
+      '@redis/graph': 1.1.1(@redis/client@1.6.0)
+      '@redis/json': 1.0.7(@redis/client@1.6.0)
+      '@redis/search': 1.2.0(@redis/client@1.6.0)
+      '@redis/time-series': 1.1.0(@redis/client@1.6.0)
+
   reflect-metadata@0.2.2: {}
 
   reflect.getprototypeof@1.0.4:
@@ -29036,6 +29171,8 @@ snapshots:
       onetime: 7.0.0
       signal-exit: 4.1.0
 
+  resumable-stream@2.0.0: {}
+
   ret@0.5.0: {}
 
   retry@0.13.1: {}
@@ -30977,7 +31114,7 @@ snapshots:
       - tsx
       - yaml
 
-  vite-plugin-checker@0.8.0(eslint@9.21.0(jiti@2.4.0))(optionator@0.9.4)(typescript@5.6.3)(vite@5.4.11(@types/node@20.17.24)(terser@5.31.3)):
+  vite-plugin-checker@0.8.0(eslint@9.21.0)(optionator@0.9.4)(typescript@5.6.3)(vite@5.4.11(@types/node@20.17.24)(terser@5.31.3)):
     dependencies:
       '@babel/code-frame': 7.26.2
       ansi-escapes: 4.3.2
@@ -30995,7 +31132,7 @@ snapshots:
       vscode-languageserver-textdocument: 1.0.11
       vscode-uri: 3.0.8
     optionalDependencies:
-      eslint: 9.21.0(jiti@2.4.0)
+      eslint: 9.21.0
       optionator: 0.9.4
       typescript: 5.6.3
 
@@ -31032,7 +31169,7 @@ snapshots:
     transitivePeerDependencies:
       - supports-color
 
-  vite-plugin-solid@2.7.2(solid-js@1.8.7):
+  vite-plugin-solid@2.7.2(solid-js@1.8.7)(vite@5.4.11(@types/node@22.7.4)(terser@5.31.3)):
     dependencies:
       '@babel/core': 7.26.0
       '@babel/preset-typescript': 7.26.0(@babel/core@7.26.0)
@@ -31041,7 +31178,8 @@ snapshots:
       merge-anything: 5.1.7
       solid-js: 1.8.7
       solid-refresh: 0.5.3(solid-js@1.8.7)
-      vitefu: 0.2.5(vite@6.0.3(@types/node@22.7.4)(jiti@2.4.0)(terser@5.31.3)(tsx@4.19.2)(yaml@2.7.0))
+      vite: 5.4.11(@types/node@22.7.4)(terser@5.31.3)
+      vitefu: 0.2.5(vite@5.4.11(@types/node@22.7.4)(terser@5.31.3))
     transitivePeerDependencies:
       - supports-color
 
@@ -31106,6 +31244,10 @@ snapshots:
       tsx: 4.19.2
       yaml: 2.7.0
 
+  vitefu@0.2.5(vite@5.4.11(@types/node@22.7.4)(terser@5.31.3)):
+    optionalDependencies:
+      vite: 5.4.11(@types/node@22.7.4)(terser@5.31.3)
+
   vitefu@0.2.5(vite@6.0.3(@types/node@22.7.4)(jiti@2.4.0)(terser@5.31.3)(tsx@4.19.2)(yaml@2.7.0)):
     optionalDependencies:
       vite: 6.0.3(@types/node@22.7.4)(jiti@2.4.0)(terser@5.31.3)(tsx@4.19.2)(yaml@2.7.0)
diff --git a/turbo.json b/turbo.json
index a3b932e805d1..f314f3aa1b40 100644
--- a/turbo.json
+++ b/turbo.json
@@ -1,9 +1,14 @@
 {
   "$schema": "https://turbo.build/schema.json",
-  "globalEnv": ["CI", "PORT"],
+  "globalEnv": [
+    "CI",
+    "PORT"
+  ],
   "tasks": {
     "build": {
-      "dependsOn": ["^build"],
+      "dependsOn": [
+        "^build"
+      ],
       "env": [
         "ANTHROPIC_API_KEY",
         "ASSISTANT_ID",
@@ -42,7 +47,8 @@
         "SENTRY_PROJECT",
         "TOGETHER_AI_API_KEY",
         "VERCEL_URL",
-        "XAI_API_KEY"
+        "XAI_API_KEY",
+        "KV_URL"
       ],
       "outputs": [
         "dist/**",
@@ -54,19 +60,32 @@
       ]
     },
     "lint": {
-      "dependsOn": ["^lint"]
+      "dependsOn": [
+        "^lint"
+      ]
     },
     "type-check": {
-      "dependsOn": ["^build", "build"]
+      "dependsOn": [
+        "^build",
+        "build"
+      ]
     },
     "test": {
-      "dependsOn": ["^build", "build"]
+      "dependsOn": [
+        "^build",
+        "build"
+      ]
     },
     "publint": {
-      "dependsOn": ["^build", "build"]
+      "dependsOn": [
+        "^build",
+        "build"
+      ]
     },
     "clean": {
-      "dependsOn": ["^clean"]
+      "dependsOn": [
+        "^clean"
+      ]
     },
     "dev": {
       "cache": false,
@@ -74,7 +93,10 @@
     },
     "prettier-check": {},
     "integration-test": {
-      "dependsOn": ["^build", "build"]
+      "dependsOn": [
+        "^build",
+        "build"
+      ]
     }
   }
 }

From 6e15bffb798909dccef800d59f58c99b77144f9b Mon Sep 17 00:00:00 2001
From: jeremyphilemon <git@jrmyphlmn.com>
Date: Fri, 25 Apr 2025 09:35:11 -0700
Subject: [PATCH 02/20] resolve merge conflicts

---
 examples/next-openai/package.json | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/examples/next-openai/package.json b/examples/next-openai/package.json
index 792620118761..c23f630f1fee 100644
--- a/examples/next-openai/package.json
+++ b/examples/next-openai/package.json
@@ -10,19 +10,11 @@
   },
   "dependencies": {
     "@ai-sdk/anthropic": "1.2.10",
-<<<<<<< Updated upstream
     "@ai-sdk/deepseek": "0.2.13",
     "@ai-sdk/fireworks": "0.2.13",
     "@ai-sdk/openai": "1.3.19",
     "@ai-sdk/google": "1.2.13",
     "@ai-sdk/google-vertex": "2.2.17",
-=======
-    "@ai-sdk/deepseek": "0.2.12",
-    "@ai-sdk/fireworks": "0.2.12",
-    "@ai-sdk/google": "1.2.12",
-    "@ai-sdk/google-vertex": "2.2.16",
-    "@ai-sdk/openai": "1.3.16",
->>>>>>> Stashed changes
     "@ai-sdk/perplexity": "1.1.7",
     "@ai-sdk/react": "1.2.9",
     "@ai-sdk/ui-utils": "1.2.8",

From fd753e4a973d8dfad830982d53d1e0d1e09fa6b5 Mon Sep 17 00:00:00 2001
From: jeremyphilemon <git@jrmyphlmn.com>
Date: Fri, 25 Apr 2025 09:47:32 -0700
Subject: [PATCH 03/20] remove KV_URL

---
 examples/next-openai/app/api/use-chat-resume/route.ts | 6 ------
 turbo.json                                            | 3 +--
 2 files changed, 1 insertion(+), 8 deletions(-)

diff --git a/examples/next-openai/app/api/use-chat-resume/route.ts b/examples/next-openai/app/api/use-chat-resume/route.ts
index 0afbf26f9557..55823bbf444c 100644
--- a/examples/next-openai/app/api/use-chat-resume/route.ts
+++ b/examples/next-openai/app/api/use-chat-resume/route.ts
@@ -19,12 +19,6 @@ import { createResumableStreamContext } from 'resumable-stream';
 // Allow streaming responses up to 30 seconds
 export const maxDuration = 30;
 
-const redisUrl = process.env.KV_URL;
-
-if (!redisUrl) {
-  throw new Error('KV_URL environment variable is not set');
-}
-
 const streamContext = createResumableStreamContext({
   waitUntil: after,
 });
diff --git a/turbo.json b/turbo.json
index f314f3aa1b40..771281cd8df5 100644
--- a/turbo.json
+++ b/turbo.json
@@ -47,8 +47,7 @@
         "SENTRY_PROJECT",
         "TOGETHER_AI_API_KEY",
         "VERCEL_URL",
-        "XAI_API_KEY",
-        "KV_URL"
+        "XAI_API_KEY"
       ],
       "outputs": [
         "dist/**",

From 7dad719a1f1ae4da13154ba402daeafb4a0fa593 Mon Sep 17 00:00:00 2001
From: jeremyphilemon <git@jrmyphlmn.com>
Date: Fri, 25 Apr 2025 10:45:11 -0700
Subject: [PATCH 04/20] move stream context creation inside handler

---
 examples/next-openai/.env.local.example              |  2 ++
 .../next-openai/app/api/use-chat-resume/route.ts     | 12 ++++++++----
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/examples/next-openai/.env.local.example b/examples/next-openai/.env.local.example
index 7de83b351115..bd742868814f 100644
--- a/examples/next-openai/.env.local.example
+++ b/examples/next-openai/.env.local.example
@@ -13,3 +13,5 @@ BLOB_READ_WRITE_TOKEN=xxxxxxx
 # Required for reasoning example
 DEEPSEEK_API_KEY=xxxxxxx
 
+# Required for resumable streams. You can create a Redis store here: https://vercel.com/marketplace/redis
+REDIS_URL=xxxxxx
diff --git a/examples/next-openai/app/api/use-chat-resume/route.ts b/examples/next-openai/app/api/use-chat-resume/route.ts
index 55823bbf444c..81ec76632265 100644
--- a/examples/next-openai/app/api/use-chat-resume/route.ts
+++ b/examples/next-openai/app/api/use-chat-resume/route.ts
@@ -19,11 +19,11 @@ import { createResumableStreamContext } from 'resumable-stream';
 // Allow streaming responses up to 30 seconds
 export const maxDuration = 30;
 
-const streamContext = createResumableStreamContext({
-  waitUntil: after,
-});
-
 export async function POST(req: Request) {
+  const streamContext = createResumableStreamContext({
+    waitUntil: after,
+  });
+
   const { id, messages }: { id: string; messages: Message[] } =
     await req.json();
 
@@ -67,6 +67,10 @@ export async function POST(req: Request) {
 }
 
 export async function GET(request: Request) {
+  const streamContext = createResumableStreamContext({
+    waitUntil: after,
+  });
+
   const { searchParams } = new URL(request.url);
   const chatId = searchParams.get('chatId');
 

From af232eea5d0a29ae55d660b2ec933dd72a5f5466 Mon Sep 17 00:00:00 2001
From: jeremyphilemon <git@jrmyphlmn.com>
Date: Fri, 25 Apr 2025 11:05:30 -0700
Subject: [PATCH 05/20] update test

---
 packages/react/src/use-chat.ui.test.tsx | 32 ++++++++++++++++++++-----
 1 file changed, 26 insertions(+), 6 deletions(-)

diff --git a/packages/react/src/use-chat.ui.test.tsx b/packages/react/src/use-chat.ui.test.tsx
index 3b9413c75bc2..e400abf244c2 100644
--- a/packages/react/src/use-chat.ui.test.tsx
+++ b/packages/react/src/use-chat.ui.test.tsx
@@ -1857,6 +1857,8 @@ describe('initialMessages', () => {
 });
 
 describe('resume ongoing stream and return assistant message', () => {
+  const controller = new TestResponseController();
+
   setupTestComponent(
     () => {
       const { messages, status, experimental_resume } = useChat({
@@ -1883,12 +1885,10 @@ describe('resume ongoing stream and return assistant message', () => {
     },
     {
       init: TestComponent => {
-        server.urls['/api/chat'].response = [
-          {
-            type: 'stream-chunks',
-            chunks: ['0:"Hello"\n', '0:"," \n', '0:" world"\n', '0:"."\n'],
-          },
-        ];
+        server.urls['/api/chat'].response = {
+          type: 'controlled-stream',
+          controller,
+        };
 
         return <TestComponent />;
       },
@@ -1899,9 +1899,29 @@ describe('resume ongoing stream and return assistant message', () => {
     await screen.findByTestId('message-0');
     expect(screen.getByTestId('message-0')).toHaveTextContent('User: hi');
 
+    await waitFor(() => {
+      expect(screen.getByTestId('status')).toHaveTextContent('ready');
+    });
+
+    controller.write('0:"Hello"\n');
+
+    await waitFor(() => {
+      expect(screen.getByTestId('status')).toHaveTextContent('streaming');
+    });
+
+    controller.write('0:"," \n');
+    controller.write('0:" world"\n')
+    controller.write('0:"."\n')
+
+    controller.close()
+
     await screen.findByTestId('message-1');
     expect(screen.getByTestId('message-1')).toHaveTextContent(
       'AI: Hello, world.',
     );
+
+    await waitFor(() => {
+      expect(screen.getByTestId('status')).toHaveTextContent('ready');
+    });
   });
 });

From 89b2f752299fde919a386e7ac6703df98703fab5 Mon Sep 17 00:00:00 2001
From: jeremyphilemon <git@jrmyphlmn.com>
Date: Fri, 25 Apr 2025 11:06:38 -0700
Subject: [PATCH 06/20] format

---
 packages/react/src/use-chat.ui.test.tsx | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/react/src/use-chat.ui.test.tsx b/packages/react/src/use-chat.ui.test.tsx
index e400abf244c2..af84aff708fc 100644
--- a/packages/react/src/use-chat.ui.test.tsx
+++ b/packages/react/src/use-chat.ui.test.tsx
@@ -1910,10 +1910,10 @@ describe('resume ongoing stream and return assistant message', () => {
     });
 
     controller.write('0:"," \n');
-    controller.write('0:" world"\n')
-    controller.write('0:"."\n')
+    controller.write('0:" world"\n');
+    controller.write('0:"."\n');
 
-    controller.close()
+    controller.close();
 
     await screen.findByTestId('message-1');
     expect(screen.getByTestId('message-1')).toHaveTextContent(

From 283eea4c9be5ff808952d7d983e79ece22fc34dc Mon Sep 17 00:00:00 2001
From: jeremyphilemon <git@jrmyphlmn.com>
Date: Fri, 25 Apr 2025 11:07:54 -0700
Subject: [PATCH 07/20] restore turbo.json

---
 turbo.json | 37 ++++++++-----------------------------
 1 file changed, 8 insertions(+), 29 deletions(-)

diff --git a/turbo.json b/turbo.json
index 771281cd8df5..a3b932e805d1 100644
--- a/turbo.json
+++ b/turbo.json
@@ -1,14 +1,9 @@
 {
   "$schema": "https://turbo.build/schema.json",
-  "globalEnv": [
-    "CI",
-    "PORT"
-  ],
+  "globalEnv": ["CI", "PORT"],
   "tasks": {
     "build": {
-      "dependsOn": [
-        "^build"
-      ],
+      "dependsOn": ["^build"],
       "env": [
         "ANTHROPIC_API_KEY",
         "ASSISTANT_ID",
@@ -59,32 +54,19 @@
       ]
     },
     "lint": {
-      "dependsOn": [
-        "^lint"
-      ]
+      "dependsOn": ["^lint"]
     },
     "type-check": {
-      "dependsOn": [
-        "^build",
-        "build"
-      ]
+      "dependsOn": ["^build", "build"]
     },
     "test": {
-      "dependsOn": [
-        "^build",
-        "build"
-      ]
+      "dependsOn": ["^build", "build"]
     },
     "publint": {
-      "dependsOn": [
-        "^build",
-        "build"
-      ]
+      "dependsOn": ["^build", "build"]
     },
     "clean": {
-      "dependsOn": [
-        "^clean"
-      ]
+      "dependsOn": ["^clean"]
     },
     "dev": {
       "cache": false,
@@ -92,10 +74,7 @@
     },
     "prettier-check": {},
     "integration-test": {
-      "dependsOn": [
-        "^build",
-        "build"
-      ]
+      "dependsOn": ["^build", "build"]
     }
   }
 }

From b475105de6281bed5b0ce24d550fd964677ca543 Mon Sep 17 00:00:00 2001
From: jeremyphilemon <git@jrmyphlmn.com>
Date: Sat, 26 Apr 2025 01:23:17 -0700
Subject: [PATCH 08/20] fix eslint error

---
 examples/next-openai/app/use-chat-resume/chat.tsx | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/examples/next-openai/app/use-chat-resume/chat.tsx b/examples/next-openai/app/use-chat-resume/chat.tsx
index e920eae6c807..72be3a8f8ba0 100644
--- a/examples/next-openai/app/use-chat-resume/chat.tsx
+++ b/examples/next-openai/app/use-chat-resume/chat.tsx
@@ -38,6 +38,8 @@ export function Chat({
     if (autoResume) {
       experimental_resume();
     }
+    // We want to disable the exhaustive deps rule here because we only want to run this effect once
+    // eslint-disable-next-line react-hooks/exhaustive-deps
   }, []);
 
   return (

From 2dd7edad998c1957b28a630290c75d47702b7deb Mon Sep 17 00:00:00 2001
From: jeremyphilemon <git@jrmyphlmn.com>
Date: Mon, 28 Apr 2025 14:17:44 -0700
Subject: [PATCH 09/20] update docs

---
 content/docs/04-ai-sdk-ui/02-chatbot.mdx      |  71 ---------
 .../03-chatbot-message-persistence.mdx        | 142 ++++++++++++++++++
 2 files changed, 142 insertions(+), 71 deletions(-)

diff --git a/content/docs/04-ai-sdk-ui/02-chatbot.mdx b/content/docs/04-ai-sdk-ui/02-chatbot.mdx
index 6494a2d06c13..8611213b06ba 100644
--- a/content/docs/04-ai-sdk-ui/02-chatbot.mdx
+++ b/content/docs/04-ai-sdk-ui/02-chatbot.mdx
@@ -634,77 +634,6 @@ messages.map(message => (
 ));
 ```
 
-## Resumable Streams (Experimental)
-
-The `useChat` hook has experimental support for resuming an ongoing chat generation stream by any client, either after a network disconnect or reloading the chat. This can be useful for building applications that involve long-running conversations or for ensuring that messages are not lost in case of network failures.
-
-The following are the pre-requisities for your chat application to support resumable streams:
-
-- Installing the [`resumable-stream`](https://www.npmjs.com/package/resumable-stream) package that helps create and manage the publisher/subscriber mechanism of the streams.
-- A [Redis](https://vercel.com/marketplace/redis) instance to store the stream state.
-- A table that tracks the stream IDs associated with a chat.
-
-To resume a chat stream, you can use the `experimental_resume` function returned by the `useChat` hook. You will typically call this function during the initial mount of the hook.
-
-```
-'use client'
-
-export function Chat() {
-  const { experimental_resume } = useChat({id});
-
-  useEffect(() => {
-    experimental_resume();
-
-    // we use an empty dependency array to
-    // ensure this effect runs only once
-  }, [])
-
-  return (
-    <div>
-      <Messages>
-      <Input/>
-    </div>
-  )
-}
-```
-
-The `experimental_resume` function makes a `GET` request to the api endpoint you've initialized the hook with (or `/api/chat` by default) and streams the contents of the stream if it is active or fails silently if it has ended.
-
-The `GET` request automatically appends the `chatId` query parameter to the URL to help identify the chat the request belongs to. Using the `chatId`, you can look up the most recent stream ID from the database and resume the stream. As a result, it is important to specify the `id` parameter in the `useChat` hook.
-
-Earlier, you must've implemented the `POST` method for `/api/chat` route to create new chat generations. When using `experimental_resume`, you must also implement the `GET` method for `/api/chat` route to resume a stream if it is active or fails silently if it has ended.
-
-```
-export async function GET() {
-  const { searchParams } = new URL(request.url);
-  const chatId = searchParams.get('chatId');
-
-  if (!chatId) {
-    return new Response('id is required', { status: 400 });
-  }
-
-  const streamIds = await loadStreams(chatId);
-
-  if (!streamIds.length) {
-    return new Response('No streams found', { status: 404 });
-  }
-
-  const recentStreamId = streamIds.at(-1);
-
-  if (!recentStreamId) {
-    return new Response('No recent stream found', { status: 404 });
-  }
-
-  const emptyDataStream = createDataStream({
-    execute: () => {},
-  });
-
-  return new Response(
-    await streamContext.resumableStream(recentStreamId, () => emptyDataStream),
-  );
-}
-```
-
 ## Attachments (Experimental)
 
 The `useChat` hook supports sending attachments along with a message as well as rendering them on the client. This can be useful for building applications that involve sending images, files, or other media content to the AI provider.
diff --git a/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx b/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
index e722005a3536..7a84f70b5ced 100644
--- a/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
+++ b/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
@@ -325,3 +325,145 @@ When the client reloads the page after a disconnect, the chat will be restored f
   the case where the client reloads the page after a disconnection, but the
   streaming is not yet complete.
 </Note>
+
+## Resuming ongoing streams
+
+<Note>This feature is experimental and may change in future versions.</Note>
+
+The `useChat` hook has experimental support for resuming an ongoing chat generation stream by any client, either after a network disconnect or by reloading the chat page. This can be useful for building applications that involve long-running conversations or for ensuring that messages are not lost in case of network failures.
+
+The following are the pre-requisities for your chat application to support resumable streams:
+
+- Installing the [`resumable-stream`](https://www.npmjs.com/package/resumable-stream) package that helps create and manage the publisher/subscriber mechanism of the streams.
+- Creating a [Redis](https://vercel.com/marketplace/redis) instance to store the stream state.
+- Creating a table that tracks the stream IDs associated with a chat.
+
+To resume a chat stream, you can use the `experimental_resume` function returned by the `useChat` hook. You will typically call this function during the initial mount of the hook.
+
+```filename="app/components/chat.tsx"
+'use client'
+
+export function Chat() {
+  const { experimental_resume } = useChat({id});
+
+  useEffect(() => {
+    experimental_resume();
+
+    // we use an empty dependency array to
+    // ensure this effect runs only once
+  }, [])
+
+  return (
+    <div>
+      <Messages>
+      <Input/>
+    </div>
+  )
+}
+```
+
+The `experimental_resume` function makes a `GET` request to your configured chat endpoint (or `/api/chat` by default) whenever your client calls it. If there’s an active stream, it will pick up where it left off, otherwise it simply finishes without error.
+
+The `GET` request automatically appends the `chatId` query parameter to the URL to help identify the chat the request belongs to. Using the `chatId`, you can look up the most recent stream ID from the database and resume the stream.
+
+```
+GET /api/chat?chatId=<your-chat-id>
+```
+
+Earlier, you must've implemented the `POST` handler for the `/api/chat` route to create new chat generations. When using `experimental_resume`, you must also implement the `GET` handler for `/api/chat` route to resume streams.
+
+### 1. Implement the GET handler
+
+Add a `GET` method to `/api/chat` that:
+
+1. Reads `chatId` from the query string
+2. Validates it’s present
+3. Loads any stored stream IDs for that chat
+4. Returns the latest one to `streamContext.resumableStream()`
+5. Falls back to an empty stream if it’s already closed
+
+```filename="app/api/chat/route.ts"
+export async function GET() {
+  const { searchParams } = new URL(request.url);
+  const chatId = searchParams.get('chatId');
+
+  if (!chatId) {
+    return new Response('id is required', { status: 400 });
+  }
+
+  const streamIds = await loadStreams(chatId);
+
+  if (!streamIds.length) {
+    return new Response('No streams found', { status: 404 });
+  }
+
+  const recentStreamId = streamIds.at(-1);
+
+  if (!recentStreamId) {
+    return new Response('No recent stream found', { status: 404 });
+  }
+
+  const emptyDataStream = createDataStream({
+    execute: () => {},
+  });
+
+  return new Response(
+    await streamContext.resumableStream(recentStreamId, () => emptyDataStream),
+  );
+}
+```
+
+After you've implemented the `GET` handler, you can update the `POST` handler to handle the creation of resumable streams.
+
+### 2. Update the POST handler
+
+When you create a brand-new chat completion, you must:
+
+1. Generate a fresh `streamId`
+2. Persist it alongside your `chatId`
+3. Kick off a `createDataStream` that pipes tokens as they arrive
+4. Hand that new stream to `streamContext.resumableStream()`
+
+```
+import { createResumableStreamContext } from 'resumable-stream';
+
+const streamContext = createResumableStreamContext({
+  waitUntil: after,
+});
+
+async function POST(request: Request) {
+  const { id, messages } = await req.json();
+  const streamId = generateId();
+
+  // Record this new stream so we can resume later
+  await appendStreamId({ chatId: id, streamId });
+
+  // Build the data stream that will emit tokens
+  const stream = createDataStream({
+    execute: dataStream => {
+      const result = streamText({
+        model: openai('gpt-4o'),
+        messages,
+        onFinish: async ({ response }) => {
+          await saveChat({
+            id,
+            messages: appendResponseMessages({
+              messages,
+              responseMessages: response.messages,
+            }),
+          });
+        },
+      });
+
+      // Return a resumable stream to the client
+      result.mergeIntoDataStream(dataStream);
+    },
+  });
+
+  return new Response(
+    await streamContext.resumableStream(streamId, () => stream),
+  );
+}
+```
+
+With both handlers, your clients can now gracefully resume ongoing streams.

From cad77ab02574b9404308136e0e179c40774901b4 Mon Sep 17 00:00:00 2001
From: jeremyphilemon <git@jrmyphlmn.com>
Date: Mon, 28 Apr 2025 14:24:04 -0700
Subject: [PATCH 10/20] add imports

---
 .../03-chatbot-message-persistence.mdx        | 26 +++++++++++++++++++
 .../app/api/use-chat-resume/route.ts          |  1 -
 2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx b/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
index 7a84f70b5ced..f0c8ef40b6dc 100644
--- a/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
+++ b/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
@@ -342,6 +342,9 @@ To resume a chat stream, you can use the `experimental_resume` function returned
 
 ```filename="app/components/chat.tsx"
 'use client'
+import { useChat } from "@ai-sdk/react";
+import { Input } from "@/components/input";
+import { Messages } from "@/components/messages";
 
 export function Chat() {
   const { experimental_resume } = useChat({id});
@@ -383,6 +386,19 @@ Add a `GET` method to `/api/chat` that:
 5. Falls back to an empty stream if it’s already closed
 
 ```filename="app/api/chat/route.ts"
+import {
+  loadStreams,
+} from '@/util/chat-store';
+import {
+  createDataStream,
+} from 'ai';
+import { after } from 'next/server';
+import { createResumableStreamContext } from 'resumable-stream';
+
+const streamContext = createResumableStreamContext({
+  waitUntil: after,
+});
+
 export async function GET() {
   const { searchParams } = new URL(request.url);
   const chatId = searchParams.get('chatId');
@@ -425,6 +441,16 @@ When you create a brand-new chat completion, you must:
 4. Hand that new stream to `streamContext.resumableStream()`
 
 ```
+import {
+  appendResponseMessages,
+  createDataStream,
+  generateId,
+  streamText,
+} from 'ai';
+import {
+  appendStreamId,
+  saveChat,
+} from '@/util/chat-store';
 import { createResumableStreamContext } from 'resumable-stream';
 
 const streamContext = createResumableStreamContext({
diff --git a/examples/next-openai/app/api/use-chat-resume/route.ts b/examples/next-openai/app/api/use-chat-resume/route.ts
index 81ec76632265..a125503fff4a 100644
--- a/examples/next-openai/app/api/use-chat-resume/route.ts
+++ b/examples/next-openai/app/api/use-chat-resume/route.ts
@@ -1,7 +1,6 @@
 import {
   appendMessageToChat,
   appendStreamId,
-  createChat,
   loadStreams,
   saveChat,
 } from '@/util/chat-store';

From cebcca3e8536a1003677139d4b08ae0efdd99a67 Mon Sep 17 00:00:00 2001
From: jeremyphilemon <git@jrmyphlmn.com>
Date: Mon, 28 Apr 2025 15:35:04 -0700
Subject: [PATCH 11/20] check for request url and method

---
 packages/react/src/use-chat.ui.test.tsx | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/packages/react/src/use-chat.ui.test.tsx b/packages/react/src/use-chat.ui.test.tsx
index af84aff708fc..3703c245a0f3 100644
--- a/packages/react/src/use-chat.ui.test.tsx
+++ b/packages/react/src/use-chat.ui.test.tsx
@@ -1922,6 +1922,14 @@ describe('resume ongoing stream and return assistant message', () => {
 
     await waitFor(() => {
       expect(screen.getByTestId('status')).toHaveTextContent('ready');
+
+      expect(server.calls.length).toBeGreaterThan(0);
+      const { calls } = server;
+      const [mostRecentCall] = calls;
+
+      const { requestMethod, requestUrl } = mostRecentCall;
+      expect(requestMethod).toBe('GET');
+      expect(requestUrl).toBe('http://localhost:3000/api/chat?chatId=123');
     });
   });
 });

From 64dc1985af28a9c043fff02af52ef5e1ee612bae Mon Sep 17 00:00:00 2001
From: jeremyphilemon <git@jrmyphlmn.com>
Date: Mon, 28 Apr 2025 15:44:01 -0700
Subject: [PATCH 12/20] update language

---
 content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx b/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
index f0c8ef40b6dc..5329c94da5cc 100644
--- a/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
+++ b/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
@@ -338,7 +338,7 @@ The following are the pre-requisities for your chat application to support resum
 - Creating a [Redis](https://vercel.com/marketplace/redis) instance to store the stream state.
 - Creating a table that tracks the stream IDs associated with a chat.
 
-To resume a chat stream, you can use the `experimental_resume` function returned by the `useChat` hook. You will typically call this function during the initial mount of the hook.
+To resume a chat stream, you will use the `experimental_resume` function returned by the `useChat` hook. You will call this function during the initial mount of the hook inside the main chat component.
 
 ```filename="app/components/chat.tsx"
 'use client'

From 9ab107d1338c928926384835ff5dcbe6617ade7c Mon Sep 17 00:00:00 2001
From: jeremyphilemon <git@jrmyphlmn.com>
Date: Tue, 29 Apr 2025 13:24:43 -0700
Subject: [PATCH 13/20] update docs and test syntax

---
 .../docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx    | 4 ++--
 packages/react/src/use-chat.ui.test.tsx                     | 6 ++++--
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx b/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
index 5329c94da5cc..73b123c939f2 100644
--- a/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
+++ b/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
@@ -385,7 +385,7 @@ Add a `GET` method to `/api/chat` that:
 4. Returns the latest one to `streamContext.resumableStream()`
 5. Falls back to an empty stream if it’s already closed
 
-```filename="app/api/chat/route.ts"
+```ts filename="app/api/chat/route.ts"
 import {
   loadStreams,
 } from '@/util/chat-store';
@@ -440,7 +440,7 @@ When you create a brand-new chat completion, you must:
 3. Kick off a `createDataStream` that pipes tokens as they arrive
 4. Hand that new stream to `streamContext.resumableStream()`
 
-```
+```ts filename="@/app/api/chat/route.ts"
 import {
   appendResponseMessages,
   createDataStream,
diff --git a/packages/react/src/use-chat.ui.test.tsx b/packages/react/src/use-chat.ui.test.tsx
index 3703c245a0f3..94ad66959fc1 100644
--- a/packages/react/src/use-chat.ui.test.tsx
+++ b/packages/react/src/use-chat.ui.test.tsx
@@ -1868,6 +1868,9 @@ describe('resume ongoing stream and return assistant message', () => {
 
       useEffect(() => {
         experimental_resume();
+
+        // We want to disable the exhaustive deps rule here because we only want to run this effect once
+        // eslint-disable-next-line react-hooks/exhaustive-deps
       }, []);
 
       return (
@@ -1924,8 +1927,7 @@ describe('resume ongoing stream and return assistant message', () => {
       expect(screen.getByTestId('status')).toHaveTextContent('ready');
 
       expect(server.calls.length).toBeGreaterThan(0);
-      const { calls } = server;
-      const [mostRecentCall] = calls;
+      const mostRecentCall = server.calls[0];
 
       const { requestMethod, requestUrl } = mostRecentCall;
       expect(requestMethod).toBe('GET');

From 02d91eccb9791f805c471d9aa444f6a1470b1ca2 Mon Sep 17 00:00:00 2001
From: jeremyphilemon <git@jrmyphlmn.com>
Date: Tue, 29 Apr 2025 13:29:20 -0700
Subject: [PATCH 14/20] specify code snippet language

---
 content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx b/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
index 73b123c939f2..a931e6df5ede 100644
--- a/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
+++ b/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
@@ -340,8 +340,9 @@ The following are the pre-requisities for your chat application to support resum
 
 To resume a chat stream, you will use the `experimental_resume` function returned by the `useChat` hook. You will call this function during the initial mount of the hook inside the main chat component.
 
-```filename="app/components/chat.tsx"
+```tsx filename="app/components/chat.tsx"
 'use client'
+
 import { useChat } from "@ai-sdk/react";
 import { Input } from "@/components/input";
 import { Messages } from "@/components/messages";
@@ -369,7 +370,7 @@ The `experimental_resume` function makes a `GET` request to your configured chat
 
 The `GET` request automatically appends the `chatId` query parameter to the URL to help identify the chat the request belongs to. Using the `chatId`, you can look up the most recent stream ID from the database and resume the stream.
 
-```
+```bash
 GET /api/chat?chatId=<your-chat-id>
 ```
 

From 99f9f6f0020fc702bc62d03f94c47241662bd86c Mon Sep 17 00:00:00 2001
From: jeremyphilemon <git@jrmyphlmn.com>
Date: Tue, 29 Apr 2025 14:04:59 -0700
Subject: [PATCH 15/20] reuse callChatApi and differentiate by new param

---
 .../03-chatbot-message-persistence.mdx        |  13 +-
 packages/react/src/use-chat.ts                | 107 ++-------------
 packages/react/src/use-chat.ui.test.tsx       |   2 +-
 packages/ui-utils/src/call-chat-api.ts        | 123 ++++--------------
 packages/ui-utils/src/index.ts                |   2 +-
 5 files changed, 39 insertions(+), 208 deletions(-)

diff --git a/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx b/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
index a931e6df5ede..91b2a7a6649a 100644
--- a/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
+++ b/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
@@ -387,12 +387,8 @@ Add a `GET` method to `/api/chat` that:
 5. Falls back to an empty stream if it’s already closed
 
 ```ts filename="app/api/chat/route.ts"
-import {
-  loadStreams,
-} from '@/util/chat-store';
-import {
-  createDataStream,
-} from 'ai';
+import { loadStreams } from '@/util/chat-store';
+import { createDataStream } from 'ai';
 import { after } from 'next/server';
 import { createResumableStreamContext } from 'resumable-stream';
 
@@ -448,10 +444,7 @@ import {
   generateId,
   streamText,
 } from 'ai';
-import {
-  appendStreamId,
-  saveChat,
-} from '@/util/chat-store';
+import { appendStreamId, saveChat } from '@/util/chat-store';
 import { createResumableStreamContext } from 'resumable-stream';
 
 const streamContext = createResumableStreamContext({
diff --git a/packages/react/src/use-chat.ts b/packages/react/src/use-chat.ts
index ef0bda759d84..af244d5fd09a 100644
--- a/packages/react/src/use-chat.ts
+++ b/packages/react/src/use-chat.ts
@@ -9,7 +9,6 @@ import type {
 } from '@ai-sdk/ui-utils';
 import {
   callChatApi,
-  resumeChatApi,
   extractMaxToolInvocationStep,
   fillMessageParts,
   generateId as generateIdFunc,
@@ -243,7 +242,10 @@ By default, it's set to 1, which means that only a single LLM call is made.
   }, [credentials, headers, body]);
 
   const triggerRequest = useCallback(
-    async (chatRequest: ChatRequest) => {
+    async (
+      chatRequest: ChatRequest,
+      requestType: 'generate' | 'resume' = 'generate',
+    ) => {
       mutateStatus('submitted');
       setError(undefined);
 
@@ -346,6 +348,7 @@ By default, it's set to 1, which means that only a single LLM call is made.
           generateId,
           fetch,
           lastMessage: chatMessages[chatMessages.length - 1],
+          requestType,
         });
 
         abortControllerRef.current = null;
@@ -407,100 +410,6 @@ By default, it's set to 1, which means that only a single LLM call is made.
     ],
   );
 
-  const triggerResumeRequest = useCallback(async () => {
-    const body = {
-      id: chatId,
-      messages: messagesRef.current,
-    };
-
-    try {
-      const abortController = new AbortController();
-      abortControllerRef.current = abortController;
-
-      const throttledMutate = throttle(mutate, throttleWaitMs);
-      const throttledMutateStreamData = throttle(
-        mutateStreamData,
-        throttleWaitMs,
-      );
-
-      const previousMessages = messagesRef.current;
-      const chatMessages = fillMessageParts(previousMessages);
-
-      const existingData = streamDataRef.current;
-
-      await resumeChatApi({
-        api,
-        body,
-        fetch,
-        onResponse,
-        restoreMessagesOnFailure() {
-          if (!keepLastMessageOnError) {
-            throttledMutate(previousMessages, false);
-          }
-        },
-        streamProtocol,
-        onUpdate({ message, data, replaceLastMessage }) {
-          mutateStatus('streaming');
-
-          throttledMutate(
-            [
-              ...(replaceLastMessage
-                ? chatMessages.slice(0, chatMessages.length - 1)
-                : chatMessages),
-              message,
-            ],
-            false,
-          );
-
-          if (data?.length) {
-            throttledMutateStreamData(
-              [...(existingData ?? []), ...data],
-              false,
-            );
-          }
-        },
-        onFinish,
-        onToolCall,
-        generateId,
-        lastMessage: chatMessages[chatMessages.length - 1],
-      });
-
-      abortControllerRef.current = null;
-
-      mutateStatus('ready');
-    } catch (error) {
-      // Ignore abort errors as they are expected.
-      if ((error as any).name === 'AbortError') {
-        abortControllerRef.current = null;
-        mutateStatus('ready');
-        return null;
-      }
-
-      if (onError && error instanceof Error) {
-        onError(error);
-      }
-
-      setError(error as Error);
-      mutateStatus('error');
-    }
-  }, [
-    api,
-    chatId,
-    fetch,
-    generateId,
-    keepLastMessageOnError,
-    mutate,
-    mutateStatus,
-    mutateStreamData,
-    onFinish,
-    onResponse,
-    onToolCall,
-    streamProtocol,
-    throttleWaitMs,
-    onError,
-    setError,
-  ]);
-
   const append = useCallback(
     async (
       message: Message | CreateMessage,
@@ -558,8 +467,10 @@ By default, it's set to 1, which means that only a single LLM call is made.
   }, []);
 
   const experimental_resume = useCallback(async () => {
-    return triggerResumeRequest();
-  }, [triggerResumeRequest]);
+    const messages = messagesRef.current;
+
+    return triggerRequest({ messages }, 'resume');
+  }, [triggerRequest]);
 
   const setMessages = useCallback(
     (messages: Message[] | ((messages: Message[]) => Message[])) => {
diff --git a/packages/react/src/use-chat.ui.test.tsx b/packages/react/src/use-chat.ui.test.tsx
index 94ad66959fc1..ee76cdff0c18 100644
--- a/packages/react/src/use-chat.ui.test.tsx
+++ b/packages/react/src/use-chat.ui.test.tsx
@@ -1903,7 +1903,7 @@ describe('resume ongoing stream and return assistant message', () => {
     expect(screen.getByTestId('message-0')).toHaveTextContent('User: hi');
 
     await waitFor(() => {
-      expect(screen.getByTestId('status')).toHaveTextContent('ready');
+      expect(screen.getByTestId('status')).toHaveTextContent('submitted');
     });
 
     controller.write('0:"Hello"\n');
diff --git a/packages/ui-utils/src/call-chat-api.ts b/packages/ui-utils/src/call-chat-api.ts
index 188f62540e77..54160b515e48 100644
--- a/packages/ui-utils/src/call-chat-api.ts
+++ b/packages/ui-utils/src/call-chat-api.ts
@@ -20,6 +20,7 @@ export async function callChatApi({
   generateId,
   fetch = getOriginalFetch(),
   lastMessage,
+  requestType = 'generate',
 }: {
   api: string;
   body: Record<string, any>;
@@ -39,17 +40,31 @@ export async function callChatApi({
   generateId: IdGenerator;
   fetch: ReturnType<typeof getOriginalFetch> | undefined;
   lastMessage: UIMessage | undefined;
+  requestType?: 'generate' | 'resume';
 }) {
-  const response = await fetch(api, {
-    method: 'POST',
-    body: JSON.stringify(body),
-    headers: {
-      'Content-Type': 'application/json',
-      ...headers,
-    },
-    signal: abortController?.()?.signal,
-    credentials,
-  }).catch(err => {
+  const request =
+    requestType === 'resume'
+      ? fetch(`${api}?chatId=${body.id}`, {
+          method: 'GET',
+          headers: {
+            'Content-Type': 'application/json',
+            ...headers,
+          },
+          signal: abortController?.()?.signal,
+          credentials,
+        })
+      : fetch(api, {
+          method: 'POST',
+          body: JSON.stringify(body),
+          headers: {
+            'Content-Type': 'application/json',
+            ...headers,
+          },
+          signal: abortController?.()?.signal,
+          credentials,
+        });
+
+  const response = await request.catch(err => {
     restoreMessagesOnFailure();
     throw err;
   });
@@ -106,91 +121,3 @@ export async function callChatApi({
     }
   }
 }
-
-export async function resumeChatApi({
-  api,
-  body,
-  fetch = getOriginalFetch(),
-  onResponse,
-  restoreMessagesOnFailure,
-  streamProtocol = 'data',
-  onUpdate,
-  onFinish,
-  onToolCall,
-  generateId,
-  lastMessage,
-}: {
-  api: string;
-  body: Record<string, any>;
-  fetch: ReturnType<typeof getOriginalFetch> | undefined;
-  onResponse: ((response: Response) => void | Promise<void>) | undefined;
-  restoreMessagesOnFailure: () => void;
-  streamProtocol: 'data' | 'text' | undefined;
-  onUpdate: (options: {
-    message: UIMessage;
-    data: JSONValue[] | undefined;
-    replaceLastMessage: boolean;
-  }) => void;
-  onFinish: UseChatOptions['onFinish'];
-  onToolCall: UseChatOptions['onToolCall'];
-  generateId: IdGenerator;
-  lastMessage: UIMessage | undefined;
-}) {
-  const { id } = body;
-
-  const response = await fetch(`${api}?chatId=${id}`, {
-    method: 'GET',
-  });
-
-  if (onResponse) {
-    try {
-      await onResponse(response);
-    } catch (err) {
-      throw err;
-    }
-  }
-
-  if (!response.ok) {
-    restoreMessagesOnFailure();
-    throw new Error(
-      (await response.text()) ?? 'Failed to fetch the chat response.',
-    );
-  }
-
-  if (!response.body) {
-    throw new Error('The response body is empty.');
-  }
-
-  switch (streamProtocol) {
-    case 'text': {
-      await processChatTextResponse({
-        stream: response.body,
-        update: onUpdate,
-        onFinish,
-        generateId,
-      });
-      return;
-    }
-
-    case 'data': {
-      await processChatResponse({
-        stream: response.body,
-        update: onUpdate,
-        lastMessage,
-        onToolCall,
-        onFinish({ message, finishReason, usage }) {
-          if (onFinish && message != null) {
-            onFinish(message, { usage, finishReason });
-          }
-        },
-        generateId,
-      });
-      return;
-    }
-
-    default: {
-      const exhaustiveCheck: never = streamProtocol;
-      throw new Error(`Unknown stream protocol: ${exhaustiveCheck}`);
-    }
-  }
-}
diff --git a/packages/ui-utils/src/index.ts b/packages/ui-utils/src/index.ts
index de388ff3cdf3..12ba2071ccb6 100644
--- a/packages/ui-utils/src/index.ts
+++ b/packages/ui-utils/src/index.ts
@@ -13,7 +13,7 @@ export type {
   AssistantStreamPart,
   AssistantStreamString,
 } from './assistant-stream-parts';
-export { callChatApi, resumeChatApi } from './call-chat-api';
+export { callChatApi } from './call-chat-api';
 export { callCompletionApi } from './call-completion-api';
 export { formatDataStreamPart, parseDataStreamPart } from './data-stream-parts';
 export type { DataStreamPart, DataStreamString } from './data-stream-parts';

From 3fc8c24f59e29d042aba7d94d641a355d31dcaa7 Mon Sep 17 00:00:00 2001
From: jeremyphilemon <git@jrmyphlmn.com>
Date: Wed, 30 Apr 2025 18:51:39 -0700
Subject: [PATCH 16/20] add function to reference and update return type

---
 content/docs/07-reference/02-ai-sdk-ui/01-use-chat.mdx | 5 +++++
 packages/react/src/use-chat.ts                         | 4 ++--
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/content/docs/07-reference/02-ai-sdk-ui/01-use-chat.mdx b/content/docs/07-reference/02-ai-sdk-ui/01-use-chat.mdx
index 3a54c09dd098..e39468051647 100644
--- a/content/docs/07-reference/02-ai-sdk-ui/01-use-chat.mdx
+++ b/content/docs/07-reference/02-ai-sdk-ui/01-use-chat.mdx
@@ -600,6 +600,11 @@ Allows you to easily create a conversational user interface for your chatbot app
       type: '() => void',
       description: 'Function to abort the current API request.',
     },
+    {
+      name: 'experimental_resume',
+      type: '() => void',
+      description: 'Function to resume an ongoing chat generation stream.',
+    }
     {
       name: 'setMessages',
       type: '(messages: Message[] | ((messages: Message[]) => Message[]) => void',
diff --git a/packages/react/src/use-chat.ts b/packages/react/src/use-chat.ts
index c1a033421d12..3c064f7677fa 100644
--- a/packages/react/src/use-chat.ts
+++ b/packages/react/src/use-chat.ts
@@ -56,7 +56,7 @@ export type UseChatHelpers = {
   /**
    * Resume an ongoing chat generation stream. This does not resume an aborted generation.
    */
-  experimental_resume: () => Promise<string | null | undefined>;
+  experimental_resume: () => void;
 
   /**
    * Update the `messages` state locally. This is useful when you want to
@@ -469,7 +469,7 @@ By default, it's set to 1, which means that only a single LLM call is made.
   const experimental_resume = useCallback(async () => {
     const messages = messagesRef.current;
 
-    return triggerRequest({ messages }, 'resume');
+    triggerRequest({ messages }, 'resume');
   }, [triggerRequest]);
 
   const setMessages = useCallback(

From 9ea0a1b07f41269c7ccf5dd70b8978c378d68784 Mon Sep 17 00:00:00 2001
From: jeremyphilemon <git@jrmyphlmn.com>
Date: Wed, 30 Apr 2025 19:03:42 -0700
Subject: [PATCH 17/20] update code snippet language

---
 content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx b/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
index 91b2a7a6649a..ab82f8fbe81b 100644
--- a/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
+++ b/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
@@ -386,7 +386,7 @@ Add a `GET` method to `/api/chat` that:
 4. Returns the latest one to `streamContext.resumableStream()`
 5. Falls back to an empty stream if it’s already closed
 
-```ts filename="app/api/chat/route.ts"
+```typescript filename="app/api/chat/route.ts"
 import { loadStreams } from '@/util/chat-store';
 import { createDataStream } from 'ai';
 import { after } from 'next/server';
@@ -437,7 +437,7 @@ When you create a brand-new chat completion, you must:
 3. Kick off a `createDataStream` that pipes tokens as they arrive
 4. Hand that new stream to `streamContext.resumableStream()`
 
-```ts filename="@/app/api/chat/route.ts"
+```typescript filename="@/app/api/chat/route.ts"
 import {
   appendResponseMessages,
   createDataStream,

From 45335647c6dd5fcdf8f0949d37b8a6ed52923c56 Mon Sep 17 00:00:00 2001
From: jeremyphilemon <git@jrmyphlmn.com>
Date: Wed, 30 Apr 2025 19:10:14 -0700
Subject: [PATCH 18/20] use tsx as language

---
 content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx b/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
index ab82f8fbe81b..1a80b1d69a90 100644
--- a/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
+++ b/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
@@ -386,7 +386,7 @@ Add a `GET` method to `/api/chat` that:
 4. Returns the latest one to `streamContext.resumableStream()`
 5. Falls back to an empty stream if it’s already closed
 
-```typescript filename="app/api/chat/route.ts"
+```tsx filename="app/api/chat/route.ts"
 import { loadStreams } from '@/util/chat-store';
 import { createDataStream } from 'ai';
 import { after } from 'next/server';
@@ -437,7 +437,7 @@ When you create a brand-new chat completion, you must:
 3. Kick off a `createDataStream` that pipes tokens as they arrive
 4. Hand that new stream to `streamContext.resumableStream()`
 
-```typescript filename="@/app/api/chat/route.ts"
+```tsx filename="@/app/api/chat/route.ts"
 import {
   appendResponseMessages,
   createDataStream,

From fef181cb8b5ae9f1b0afd4cbdbfcccf8cc021f04 Mon Sep 17 00:00:00 2001
From: jeremyphilemon <git@jrmyphlmn.com>
Date: Wed, 30 Apr 2025 19:14:52 -0700
Subject: [PATCH 19/20] revert to ts

---
 content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx b/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
index 1a80b1d69a90..91b2a7a6649a 100644
--- a/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
+++ b/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
@@ -386,7 +386,7 @@ Add a `GET` method to `/api/chat` that:
 4. Returns the latest one to `streamContext.resumableStream()`
 5. Falls back to an empty stream if it’s already closed
 
-```tsx filename="app/api/chat/route.ts"
+```ts filename="app/api/chat/route.ts"
 import { loadStreams } from '@/util/chat-store';
 import { createDataStream } from 'ai';
 import { after } from 'next/server';
@@ -437,7 +437,7 @@ When you create a brand-new chat completion, you must:
 3. Kick off a `createDataStream` that pipes tokens as they arrive
 4. Hand that new stream to `streamContext.resumableStream()`
 
-```tsx filename="@/app/api/chat/route.ts"
+```ts filename="@/app/api/chat/route.ts"
 import {
   appendResponseMessages,
   createDataStream,

From 05e3ce429f869ea4d1cf6a605fd5d4a5eb9bbdad Mon Sep 17 00:00:00 2001
From: jeremyphilemon <git@jrmyphlmn.com>
Date: Wed, 30 Apr 2025 19:31:58 -0700
Subject: [PATCH 20/20] use consistent path

---
 content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx b/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
index 91b2a7a6649a..e690aa6e6495 100644
--- a/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
+++ b/content/docs/04-ai-sdk-ui/03-chatbot-message-persistence.mdx
@@ -437,7 +437,7 @@ When you create a brand-new chat completion, you must:
 3. Kick off a `createDataStream` that pipes tokens as they arrive
 4. Hand that new stream to `streamContext.resumableStream()`
 
-```ts filename="@/app/api/chat/route.ts"
+```ts filename="app/api/chat/route.ts"
 import {
   appendResponseMessages,
   createDataStream,