fix(frontend): fallback Streamdown clipboard copy (#3397)

* fix(frontend): fallback streamdown clipboard copy

* fix(frontend): address clipboard fallback review

* fix(frontend): normalize clipboard fallback rejection

* fix(frontend): harden clipboard fallback install

* fix(frontend): clarify clipboard fallback errors

* fix(frontend): cover clipboard fallback edge cases

* fix(frontend): tighten clipboard fallback cleanup

* fix(frontend): reduce clipboard fallback copy window

* fix(frontend): guard clipboard item fallback install

* fix(frontend): clean up clipboard fallback on selection errors

* Address clipboard fallback review feedback

* fix(frontend): guard clipboard fallback install during SSR

frontend/src/components/ai-elements/message.tsx

@@ -18,7 +18,8 @@ import {
 } from "lucide-react";
 import type { ComponentProps, HTMLAttributes, ReactElement } from "react";
 import { createContext, memo, useContext, useEffect, useState } from "react";
-import { Streamdown } from "streamdown";
+
+import { ClipboardSafeStreamdown } from "./streamdown";
 
 export type MessageProps = HTMLAttributes<HTMLDivElement> & {
   from: UIMessage["role"];
@@ -302,11 +303,13 @@ export const MessageBranchPage = ({
   );
 };
 
-export type MessageResponseProps = ComponentProps<typeof Streamdown>;
+export type MessageResponseProps = ComponentProps<
+  typeof ClipboardSafeStreamdown
+>;
 
 export const MessageResponse = memo(
   ({ className, ...props }: MessageResponseProps) => (
-    <Streamdown
+    <ClipboardSafeStreamdown
       className={cn(
         "size-full [&>*:first-child]:mt-0 [&>*:last-child]:mb-0",
         className,

frontend/src/components/ai-elements/reasoning.tsx

@@ -10,9 +10,9 @@ import { cn } from "@/lib/utils";
 import { BrainIcon, ChevronDownIcon } from "lucide-react";
 import type { ComponentProps, ReactNode } from "react";
 import { createContext, memo, useContext, useEffect, useState } from "react";
-import { Streamdown } from "streamdown";
 import { reasoningPlugins } from "@/core/streamdown/plugins";
 import { Shimmer } from "./shimmer";
+import { ClipboardSafeStreamdown } from "./streamdown";
 
 type ReasoningContextValue = {
   isStreaming: boolean;
@@ -178,7 +178,9 @@ export const ReasoningContent = memo(
       )}
       {...props}
     >
-      <Streamdown {...reasoningPlugins}>{children}</Streamdown>
+      <ClipboardSafeStreamdown {...reasoningPlugins}>
+        {children}
+      </ClipboardSafeStreamdown>
     </CollapsibleContent>
   ),
 );

frontend/src/components/ai-elements/streamdown.tsx

@@ -0,0 +1,17 @@
+"use client";
+
+import { type ComponentProps } from "react";
+import { Streamdown } from "streamdown";
+
+import { installClipboardFallback } from "@/core/clipboard";
+
+export type ClipboardSafeStreamdownProps = ComponentProps<typeof Streamdown>;
+
+// Only patch browser globals in client context; skip during SSR
+if (typeof document !== "undefined") {
+  installClipboardFallback();
+}
+
+export function ClipboardSafeStreamdown(props: ClipboardSafeStreamdownProps) {
+  return <Streamdown {...props} />;
+}

frontend/src/components/workspace/artifacts/artifact-file-detail.tsx

@@ -10,7 +10,6 @@ import {
 } from "lucide-react";
 import { useCallback, useEffect, useMemo, useRef, useState } from "react";
 import { toast } from "sonner";
-import { Streamdown } from "streamdown";
 
 import {
   Artifact,
@@ -20,6 +19,7 @@ import {
   ArtifactHeader,
   ArtifactTitle,
 } from "@/components/ai-elements/artifact";
+import { ClipboardSafeStreamdown } from "@/components/ai-elements/streamdown";
 import { Select, SelectItem } from "@/components/ui/select";
 import {
   SelectContent,
@@ -400,13 +400,13 @@ export function ArtifactFilePreview({
   if (language === "markdown") {
     return (
       <div className="size-full px-4">
-        <Streamdown
+        <ClipboardSafeStreamdown
           className="size-full"
           {...streamdownPlugins}
           components={{ a: ArtifactLink }}
         >
           {content ?? ""}
-        </Streamdown>
+        </ClipboardSafeStreamdown>
       </div>
     );
   }

frontend/src/components/workspace/messages/subtask-card.tsx

@@ -6,7 +6,6 @@ import {
   XCircleIcon,
 } from "lucide-react";
 import { useMemo, useState } from "react";
-import { Streamdown } from "streamdown";
 
 import {
   ChainOfThought,
@@ -14,6 +13,7 @@ import {
   ChainOfThoughtStep,
 } from "@/components/ai-elements/chain-of-thought";
 import { Shimmer } from "@/components/ai-elements/shimmer";
+import { ClipboardSafeStreamdown } from "@/components/ai-elements/streamdown";
 import { Button } from "@/components/ui/button";
 import { ShineBorder } from "@/components/ui/shine-border";
 import { useI18n } from "@/core/i18n/hooks";
@@ -126,12 +126,12 @@ export function SubtaskCard({
           {task.prompt && (
             <ChainOfThoughtStep
               label={
-                <Streamdown
+                <ClipboardSafeStreamdown
                   {...streamdownPluginsWithWordAnimation}
                   components={{ a: CitationLink }}
                 >
                   {task.prompt}
-                </Streamdown>
+                </ClipboardSafeStreamdown>
               }
             ></ChainOfThoughtStep>
           )}

frontend/src/components/workspace/settings/about-settings-page.tsx

@@ -1,9 +1,9 @@
 "use client";
 
-import { Streamdown } from "streamdown";
+import { ClipboardSafeStreamdown } from "@/components/ai-elements/streamdown";
 
 import { aboutMarkdown } from "./about-content";
 
 export function AboutSettingsPage() {
-  return <Streamdown>{aboutMarkdown}</Streamdown>;
+  return <ClipboardSafeStreamdown>{aboutMarkdown}</ClipboardSafeStreamdown>;
 }

frontend/src/components/workspace/settings/memory-settings-page.tsx

@@ -10,8 +10,8 @@ import {
 import Link from "next/link";
 import { useDeferredValue, useId, useRef, useState } from "react";
 import { toast } from "sonner";
-import { Streamdown } from "streamdown";
 
+import { ClipboardSafeStreamdown } from "@/components/ai-elements/streamdown";
 import { Button } from "@/components/ui/button";
 import {
   Dialog,
@@ -639,12 +639,12 @@ export function MemorySettingsPage() {
                 <div className="text-muted-foreground mb-4 text-sm">
                   {summaryReadOnly}
                 </div>
-                <Streamdown
+                <ClipboardSafeStreamdown
                   className="size-full min-w-0 [overflow-wrap:anywhere] [&>*:first-child]:mt-0 [&>*:last-child]:mb-0"
                   {...streamdownPlugins}
                 >
                   {summariesToMarkdown(memory, filteredSectionGroups, t)}
-                </Streamdown>
+                </ClipboardSafeStreamdown>
               </div>
             ) : null}