feat(ui): Add copy button for code blocks in mothership (#4033)

* Add copy button for code blocks in mothership

* Move to shared copy code button

* Handle react node case for copy

* fix(copy-button): address PR review feedback

- Await clipboard write and clear timeout on unmount in CopyCodeButton
- Fix hover bg color matching container bg (surface-4 -> surface-5)
- Extract extractTextContent to shared util at lib/core/utils/react-node-text.ts

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* Fix lint

---------

Co-authored-by: Theodore Li <theo@sim.ai>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/sim/app/chat/components/message/components/markdown-renderer.tsx

@@ -2,6 +2,8 @@ import React, { type HTMLAttributes, memo, type ReactNode, useMemo } from 'react
 import ReactMarkdown from 'react-markdown'
 import remarkGfm from 'remark-gfm'
 import { Tooltip } from '@/components/emcn'
+import { CopyCodeButton } from '@/components/ui/copy-code-button'
+import { extractTextContent } from '@/lib/core/utils/react-node-text'
 
 export function LinkWithPreview({ href, children }: { href: string; children: React.ReactNode }) {
   return (
@@ -102,6 +104,10 @@ function createCustomComponents(LinkComponent: typeof LinkWithPreview) {
             <span className='font-sans text-gray-400 text-xs'>
               {codeProps.className?.replace('language-', '') || 'code'}
             </span>
+            <CopyCodeButton
+              code={extractTextContent(codeContent)}
+              className='text-gray-400 hover:bg-gray-700 hover:text-gray-200'
+            />
           </div>
           <pre className='overflow-x-auto p-4 font-mono text-gray-200 dark:text-gray-100'>
             {codeContent}

apps/sim/app/workspace/[workspaceId]/home/components/message-content/components/chat-content/chat-content.tsx

@@ -9,7 +9,9 @@ import 'prismjs/components/prism-css'
 import 'prismjs/components/prism-markup'
 import '@/components/emcn/components/code/code.css'
 import { Checkbox, highlight, languages } from '@/components/emcn'
+import { CopyCodeButton } from '@/components/ui/copy-code-button'
 import { cn } from '@/lib/core/utils/cn'
+import { extractTextContent } from '@/lib/core/utils/react-node-text'
 import {
   PendingTagIndicator,
   parseSpecialTags,
@@ -33,16 +35,6 @@ const LANG_ALIASES: Record<string, string> = {
   py: 'python',
 }
 
-function extractTextContent(node: React.ReactNode): string {
-  if (typeof node === 'string') return node
-  if (typeof node === 'number') return String(node)
-  if (!node) return ''
-  if (Array.isArray(node)) return node.map(extractTextContent).join('')
-  if (isValidElement(node))
-    return extractTextContent((node.props as { children?: React.ReactNode }).children)
-  return ''
-}
-
 const PROSE_CLASSES = cn(
   'prose prose-base dark:prose-invert max-w-none',
   'font-[family-name:var(--font-inter)] antialiased break-words font-[430] tracking-[0]',
@@ -125,11 +117,13 @@ const MARKDOWN_COMPONENTS: React.ComponentProps<typeof ReactMarkdown>['component
 
     return (
       <div className='not-prose my-6 overflow-hidden rounded-lg border border-[var(--divider)]'>
-        {language && (
-          <div className='border-[var(--divider)] border-b bg-[var(--surface-4)] px-4 py-2 text-[var(--text-tertiary)] text-xs dark:bg-[var(--surface-4)]'>
-            {language}
-          </div>
-        )}
+        <div className='flex items-center justify-between border-[var(--divider)] border-b bg-[var(--surface-4)] px-4 py-2 dark:bg-[var(--surface-4)]'>
+          <span className='text-[var(--text-tertiary)] text-xs'>{language || 'code'}</span>
+          <CopyCodeButton
+            code={codeString}
+            className='text-[var(--text-tertiary)] hover:bg-[var(--surface-5)] hover:text-[var(--text-secondary)]'
+          />
+        </div>
         <div className='code-editor-theme bg-[var(--surface-5)] dark:bg-[var(--code-bg)]'>
           <pre
             className='m-0 overflow-x-auto whitespace-pre p-4 font-[430] font-mono text-[var(--text-primary)] text-small leading-[21px]'

apps/sim/components/ui/copy-code-button.tsx

@@ -0,0 +1,42 @@
+'use client'
+
+import { useCallback, useEffect, useRef, useState } from 'react'
+import { Check, Copy } from '@/components/emcn'
+import { cn } from '@/lib/core/utils/cn'
+
+interface CopyCodeButtonProps {
+  code: string
+  className?: string
+}
+
+export function CopyCodeButton({ code, className }: CopyCodeButtonProps) {
+  const [copied, setCopied] = useState(false)
+  const timerRef = useRef<ReturnType<typeof setTimeout> | null>(null)
+
+  const handleCopy = useCallback(async () => {
+    await navigator.clipboard.writeText(code)
+    setCopied(true)
+    if (timerRef.current) clearTimeout(timerRef.current)
+    timerRef.current = setTimeout(() => setCopied(false), 2000)
+  }, [code])
+
+  useEffect(
+    () => () => {
+      if (timerRef.current) clearTimeout(timerRef.current)
+    },
+    []
+  )
+
+  return (
+    <button
+      type='button'
+      onClick={handleCopy}
+      className={cn(
+        'flex items-center gap-1 rounded px-1.5 py-0.5 text-xs transition-colors',
+        className
+      )}
+    >
+      {copied ? <Check className='size-3.5' /> : <Copy className='size-3.5' />}
+    </button>
+  )
+}

apps/sim/lib/core/utils/react-node-text.ts

@@ -0,0 +1,14 @@
+import { isValidElement, type ReactNode } from 'react'
+
+/**
+ * Recursively extracts plain text content from a React node tree.
+ */
+export function extractTextContent(node: ReactNode): string {
+  if (typeof node === 'string') return node
+  if (typeof node === 'number') return String(node)
+  if (!node) return ''
+  if (Array.isArray(node)) return node.map(extractTextContent).join('')
+  if (isValidElement(node))
+    return extractTextContent((node.props as { children?: ReactNode }).children)
+  return ''
+}