Vercel AI SDK 5 Migration

app/components/DebugPromptView.tsx

@@ -114,10 +114,12 @@ function getMessageCharCount(message: CoreMessage): number {
       if (isTextPart(part)) return sum + part.text.length;
       if (isFilePart(part) && typeof part.data === 'string') return sum + part.data.length;
       if (isToolCallPart(part)) {
-        return sum + part.toolName.length + part.toolCallId.length + JSON.stringify(part.args).length;
+        // AI SDK 5: args renamed to input
+        return sum + part.toolName.length + part.toolCallId.length + JSON.stringify(part.input).length;
       }
       if (part.type === 'tool-result') {
-        return sum + part.toolName.length + part.toolCallId.length + JSON.stringify(part.result).length;
+        // AI SDK 5: result renamed to output
+        return sum + part.toolName.length + part.toolCallId.length + JSON.stringify(part.output).length;
       }
       return sum;
     }, 0);
@@ -320,7 +322,7 @@ function MessageContentView({ content, showRawJson = false }: MessageContentView
             const fileData = typeof part.data === 'string' ? part.data : '[Binary Data]';
             return (
               <div key={idx} className="rounded bg-purple-50 p-2 dark:bg-purple-900/10">
-                <div className="text-xs font-medium text-purple-500">file: {part.filename || part.mimeType}</div>
+                <div className="text-xs font-medium text-purple-500">file: {part.filename || part.mediaType}</div>
                 <div className="whitespace-pre-wrap font-mono text-sm">{fileData}</div>
               </div>
             );

app/components/ExistingChat.client.tsx

@@ -10,6 +10,7 @@ import { useReloadMessages } from '~/lib/stores/startup/reloadMessages';
 import { useSplines } from '~/lib/splines';
 import { UserProvider } from '~/components/UserProvider';
 import { Toaster } from '~/components/ui/Toaster';
+import { isToolUIPart, getToolName } from 'ai';
 
 export function ExistingChat({ chatId }: { chatId: string }) {
   // Fill in the chatID store from props early in app initialization. If this
@@ -74,7 +75,9 @@ function ExistingChatWrapper({ chatId }: { chatId: string }) {
   const hadSuccessfulDeploy = initialMessages?.some(
     (message) =>
       message.role === 'assistant' &&
-      message.parts?.some((part) => part.type === 'tool-invocation' && part.toolInvocation.toolName === 'deploy'),
+      // In AI SDK 5, tool parts are identified via isToolUIPart helper
+      // toolName is accessed via getToolName() helper
+      message.parts?.some((part) => isToolUIPart(part) && getToolName(part) === 'deploy'),
   );
 
   if (initialMessages === null) {

app/components/Homepage.client.tsx

@@ -4,7 +4,7 @@ import { useRef } from 'react';
 import { useConvexChatHomepage } from '~/lib/stores/startup';
 import { Toaster } from '~/components/ui/Toaster';
 import { setPageLoadChatId } from '~/lib/stores/chatId';
-import type { Message } from '@ai-sdk/react';
+import type { UIMessage } from 'ai';
 import type { PartCache } from '~/lib/hooks/useMessageParser';
 import { UserProvider } from '~/components/UserProvider';
 
@@ -43,4 +43,4 @@ const ChatWrapper = ({ initialId }: { initialId: string }) => {
   );
 };
 
-const emptyList: Message[] = [];
+const emptyList: UIMessage[] = [];

app/components/chat/AssistantMessage.tsx

@@ -1,6 +1,18 @@
 import { memo, useMemo } from 'react';
 import { Markdown } from './Markdown';
-import type { Message } from 'ai';
+import type { UIMessage } from 'ai';
+import { isToolUIPart } from 'ai';
+
+// Helper to extract text content from UIMessage parts
+function getMessageContent(message: UIMessage): string {
+  if (!message.parts) {
+    return '';
+  }
+  return message.parts
+    .filter((p): p is { type: 'text'; text: string } => p.type === 'text')
+    .map((p) => p.text)
+    .join('');
+}
 import { ToolCall } from './ToolCall';
 import { makePartId, type PartId } from 'chef-agent/partId.js';
 import { ExclamationTriangleIcon, DotFilledIcon } from '@radix-ui/react-icons';
@@ -10,16 +22,19 @@ import { calculateChefTokens, usageFromGeneration, type ChefTokenBreakdown } fro
 import { captureMessage } from '@sentry/remix';
 
 interface AssistantMessageProps {
-  message: Message;
+  message: UIMessage;
 }
 
 export const AssistantMessage = memo(function AssistantMessage({ message }: AssistantMessageProps) {
   const { showUsageAnnotations } = useLaunchDarkly();
-  const parsedAnnotations = useMemo(() => parseAnnotations(message.annotations), [message.annotations]);
+  // TODO: In AI SDK 5, annotations are handled differently - they're now in message.metadata
+  // or sent as custom data parts. For now, access via any cast for backwards compatibility.
+  const messageAny = message as any;
+  const parsedAnnotations = useMemo(() => parseAnnotations(messageAny.annotations ?? []), [messageAny.annotations]);
   if (!message.parts) {
     return (
       <div className="w-full overflow-hidden">
-        <Markdown html>{message.content}</Markdown>
+        <Markdown html>{getMessageContent(message)}</Markdown>
       </div>
     );
   }
@@ -64,22 +79,23 @@ function AssistantMessagePart({
   partId,
   parsedAnnotations,
 }: {
-  part: NonNullable<Message['parts']>[number];
+  part: NonNullable<UIMessage['parts']>[number];
   showUsageAnnotations: boolean;
   partId: PartId;
   parsedAnnotations: ReturnType<typeof parseAnnotations>;
 }) {
-  if (part.type === 'tool-invocation') {
+  // In AI SDK 5, tool parts have type `tool-${toolName}` and properties directly on the part
+  if (isToolUIPart(part)) {
     return (
       <>
         {showUsageAnnotations &&
           displayModelAndUsage({
-            model: parsedAnnotations.modelForToolCall[part.toolInvocation.toolCallId],
-            usageAnnotation: parsedAnnotations.usageForToolCall[part.toolInvocation.toolCallId] ?? undefined,
+            model: parsedAnnotations.modelForToolCall[part.toolCallId],
+            usageAnnotation: parsedAnnotations.usageForToolCall[part.toolCallId] ?? undefined,
             showUsageAnnotations,
           })}
 
-        <ToolCall partId={partId} toolCallId={part.toolInvocation.toolCallId} />
+        <ToolCall partId={partId} toolCallId={part.toolCallId} />
       </>
     );
   }

app/components/chat/BaseChat.client.tsx

@@ -1,5 +1,6 @@
 import { Sheet } from '@ui/Sheet';
-import type { Message } from 'ai';
+import type { UIMessage } from 'ai';
+import { getTextFromParts } from '~/lib/common/messageHelpers';
 import React, { type ReactNode, type RefCallback, useCallback, useEffect, useMemo, useState } from 'react';
 import Landing from '~/components/landing/Landing';
 import { Workbench } from '~/components/workbench/Workbench.client';
@@ -48,7 +49,7 @@ interface BaseChatProps {
   streamStatus: 'streaming' | 'submitted' | 'ready' | 'error';
   currentError: Error | undefined;
   toolStatus: ToolStatus;
-  messages: Message[];
+  messages: UIMessage[];
   terminalInitializationOptions: TerminalInitializationOptions | undefined;
   disableChatMessage: ReactNode | string | null;
 
@@ -134,7 +135,7 @@ export const BaseChat = React.forwardRef<HTMLDivElement, BaseChatProps>(
     const lastUserMessage = messages.findLast((message) => message.role === 'user');
     const resendMessage = useCallback(async () => {
       if (lastUserMessage) {
-        await onSend?.(lastUserMessage.content);
+        await onSend?.(getTextFromParts(lastUserMessage));
       }
     }, [lastUserMessage, onSend]);
     const baseChat = (