diff --git a/packages/ui/src/components/markdown.tsx b/packages/ui/src/components/markdown.tsx
index 4ec0c5d7e..91d40793d 100644
--- a/packages/ui/src/components/markdown.tsx
+++ b/packages/ui/src/components/markdown.tsx
@@ -15,6 +15,7 @@ interface ResolvedMarkdownSnapshot {
   themeKey: string
   highlightEnabled: boolean
   escapeRawHtml: boolean
+  defaultCodeBlockWrap: boolean
   partId: string | undefined
   cacheId: string
   version: string
@@ -96,6 +97,7 @@ interface MarkdownProps {
   size?: "base" | "sm" | "tight"
   disableHighlight?: boolean
   escapeRawHtml?: boolean
+  defaultCodeBlockWrap?: boolean
   onRendered?: () => void
 }
 
@@ -105,11 +107,54 @@ export function Markdown(props: MarkdownProps) {
   let containerRef: HTMLDivElement | undefined
   let latestRequestKey = ""
   let cleanupLanguageListener: (() => void) | undefined
+  const codeBlockWrapOverrides = new Map<string, boolean>()
 
   const notifyRendered = () => {
     Promise.resolve().then(() => props.onRendered?.())
   }
 
+  const codeBlockWrapKey = (codeBlock: HTMLElement): string | null => {
+    const key = codeBlock.getAttribute("data-code-block-key")
+    if (!key) {
+      return null
+    }
+    return `${resolved().cacheId}:${key}`
+  }
+
+  const applyCodeBlockWrapState = (codeBlock: HTMLElement, enabled: boolean) => {
+    codeBlock.setAttribute("data-wrap-lines", enabled ? "true" : "false")
+
+    const button = codeBlock.querySelector<HTMLButtonElement>(".code-block-wrap")
+    if (!button) {
+      return
+    }
+
+    const label = enabled ? t("markdown.codeBlock.wrap.disable") : t("markdown.codeBlock.wrap.enable")
+    button.classList.toggle("active", enabled)
+    button.setAttribute("aria-pressed", enabled ? "true" : "false")
+    button.setAttribute("aria-label", label)
+    button.setAttribute("title", label)
+
+    const text = button.querySelector(".wrap-text")
+    if (text) {
+      text.textContent = label
+    }
+  }
+
+  const syncCodeBlockWrapStates = () => {
+    if (!containerRef) {
+      return
+    }
+
+    const codeBlocks = containerRef.querySelectorAll<HTMLElement>(".markdown-code-block")
+    for (const codeBlock of codeBlocks) {
+      const key = codeBlockWrapKey(codeBlock)
+      const defaultEnabled = codeBlock.getAttribute("data-wrap-lines") !== "false"
+      const enabled = key ? (codeBlockWrapOverrides.get(key) ?? defaultEnabled) : defaultEnabled
+      applyCodeBlockWrapState(codeBlock, enabled)
+    }
+  }
+
   const resolved = createMemo(() => {
     const part = props.part
     const rawText = typeof part.text === "string" ? part.text : ""
@@ -117,11 +162,23 @@ export function Markdown(props: MarkdownProps) {
     const themeKey = Boolean(props.isDark) ? "dark" : "light"
     const highlightEnabled = !props.disableHighlight
     const escapeRawHtml = Boolean(props.escapeRawHtml)
+    const defaultCodeBlockWrap = props.defaultCodeBlockWrap ?? true
     const partId = typeof part.id === "string" && part.id.length > 0 ? part.id : undefined
     const cacheId = resolvePartCacheId(part, text)
     const version = resolvePartVersion(part, text)
-    const requestKey = `${cacheId}:${themeKey}:${highlightEnabled ? 1 : 0}:${escapeRawHtml ? 1 : 0}:${version}`
-    return { part, text, themeKey, highlightEnabled, escapeRawHtml, partId, cacheId, version, requestKey }
+    const requestKey = `${cacheId}:${themeKey}:${highlightEnabled ? 1 : 0}:${escapeRawHtml ? 1 : 0}:${defaultCodeBlockWrap ? 1 : 0}:${version}`
+    return {
+      part,
+      text,
+      themeKey,
+      highlightEnabled,
+      escapeRawHtml,
+      defaultCodeBlockWrap,
+      partId,
+      cacheId,
+      version,
+      requestKey,
+    }
   })
 
   const cacheHandle = useGlobalCache({
@@ -129,8 +186,8 @@ export function Markdown(props: MarkdownProps) {
     sessionId: () => props.sessionId,
     scope: "markdown",
     cacheId: () => {
-      const { cacheId, themeKey, highlightEnabled } = resolved()
-      return `${cacheId}:${themeKey}:${highlightEnabled ? 1 : 0}:${resolved().escapeRawHtml ? 1 : 0}`
+      const { cacheId, themeKey, highlightEnabled, escapeRawHtml, defaultCodeBlockWrap } = resolved()
+      return `${cacheId}:${themeKey}:${highlightEnabled ? 1 : 0}:${escapeRawHtml ? 1 : 0}:${defaultCodeBlockWrap ? 1 : 0}`
     },
     version: () => resolved().version,
   })
@@ -144,7 +201,7 @@ export function Markdown(props: MarkdownProps) {
       text: snapshot.text,
       html: renderedHtml,
       theme: snapshot.themeKey,
-      mode: `${snapshot.version}:${snapshot.escapeRawHtml ? "escaped" : "raw"}`,
+      mode: `${snapshot.version}:${snapshot.escapeRawHtml ? "escaped" : "raw"}:${snapshot.defaultCodeBlockWrap ? "wrap" : "nowrap"}`,
     }
     setHtml(renderedHtml)
     if (options?.cache ?? true) {
@@ -159,6 +216,7 @@ export function Markdown(props: MarkdownProps) {
     const rendered = await markdown.renderMarkdown(snapshot.text, {
       suppressHighlight: !snapshot.highlightEnabled,
       escapeRawHtml: snapshot.escapeRawHtml,
+      defaultCodeBlockWrap: snapshot.defaultCodeBlockWrap,
     })
     const shouldCache = !snapshot.highlightEnabled || !markdown.hasPendingCodeHighlight(snapshot.text)
 
@@ -170,7 +228,7 @@ export function Markdown(props: MarkdownProps) {
   createEffect(() => {
     const snapshot = resolved()
     latestRequestKey = snapshot.requestKey
-    const cacheMode = `${snapshot.version}:${snapshot.escapeRawHtml ? "escaped" : "raw"}`
+    const cacheMode = `${snapshot.version}:${snapshot.escapeRawHtml ? "escaped" : "raw"}:${snapshot.defaultCodeBlockWrap ? "wrap" : "nowrap"}`
 
     const cacheMatches = (cache: RenderCache | undefined) => {
       if (!cache) return false
@@ -202,9 +260,33 @@ export function Markdown(props: MarkdownProps) {
     })
   })
 
+  createEffect(() => {
+    html()
+    Promise.resolve().then(syncCodeBlockWrapStates)
+  })
+
   onMount(() => {
     const handleClick = async (event: Event) => {
       const target = event.target as HTMLElement
+      const wrapButton = target.closest(".code-block-wrap") as HTMLButtonElement
+      if (wrapButton) {
+        event.preventDefault()
+        const codeBlock = wrapButton.closest(".markdown-code-block") as HTMLElement | null
+        if (!codeBlock) {
+          return
+        }
+
+        const key = codeBlockWrapKey(codeBlock)
+        const current = codeBlock.getAttribute("data-wrap-lines") !== "false"
+        const next = !current
+        if (key) {
+          codeBlockWrapOverrides.set(key, next)
+        }
+        applyCodeBlockWrapState(codeBlock, next)
+        props.onRendered?.()
+        return
+      }
+
       const copyButton = target.closest(".code-block-copy") as HTMLButtonElement
 
       if (!copyButton) {
diff --git a/packages/ui/src/components/tool-call/markdown-render.tsx b/packages/ui/src/components/tool-call/markdown-render.tsx
index a2f385d1f..2c389ac48 100644
--- a/packages/ui/src/components/tool-call/markdown-render.tsx
+++ b/packages/ui/src/components/tool-call/markdown-render.tsx
@@ -30,7 +30,8 @@ export function createMarkdownContentRenderer(params: {
 
     const size = options.size || "default"
     const disableHighlight = options.disableHighlight || false
-    const messageClass = `message-text tool-call-markdown${size === "large" ? " tool-call-markdown-large" : ""}${options.wrap ? " tool-call-markdown-wrap" : ""}`
+    const wrapEnabled = options.wrap ?? true
+    const messageClass = `message-text tool-call-markdown${size === "large" ? " tool-call-markdown-large" : ""}${wrapEnabled ? " tool-call-markdown-wrap" : ""}`
     const state = params.toolState()
     const disableScrollTracking = options.disableScrollTracking || (state?.status !== "running" && state?.status !== "pending")
     const registerRef = disableScrollTracking ? registerUntracked : registerTracked
@@ -73,6 +74,7 @@ export function createMarkdownContentRenderer(params: {
           sessionId={params.sessionId}
           isDark={params.isDark()}
           disableHighlight={disableHighlight}
+          defaultCodeBlockWrap={wrapEnabled}
           onRendered={handleMarkdownRendered}
         />
         {params.scrollHelpers.renderSentinel({ disableTracking: disableScrollTracking })}
diff --git a/packages/ui/src/lib/i18n/messages/de/markdown.ts b/packages/ui/src/lib/i18n/messages/de/markdown.ts
index 83d1e7fc1..a37d77922 100644
--- a/packages/ui/src/lib/i18n/messages/de/markdown.ts
+++ b/packages/ui/src/lib/i18n/messages/de/markdown.ts
@@ -2,6 +2,8 @@ export const markdownMessages = {
   "markdown.codeBlock.copy.label": "Kopieren",
   "markdown.codeBlock.copy.copied": "Kopiert!",
   "markdown.codeBlock.copy.failed": "Fehlgeschlagen",
+  "markdown.codeBlock.wrap.enable": "Zeilenumbruch aktivieren",
+  "markdown.codeBlock.wrap.disable": "Zeilenumbruch deaktivieren",
 
   "markdown.copy": "Kopieren",
 } as const
diff --git a/packages/ui/src/lib/i18n/messages/en/markdown.ts b/packages/ui/src/lib/i18n/messages/en/markdown.ts
index c7aea2cc8..5a47fc0d6 100644
--- a/packages/ui/src/lib/i18n/messages/en/markdown.ts
+++ b/packages/ui/src/lib/i18n/messages/en/markdown.ts
@@ -2,6 +2,8 @@ export const markdownMessages = {
   "markdown.codeBlock.copy.label": "Copy",
   "markdown.codeBlock.copy.copied": "Copied!",
   "markdown.codeBlock.copy.failed": "Failed",
+  "markdown.codeBlock.wrap.enable": "Enable word wrap",
+  "markdown.codeBlock.wrap.disable": "Disable word wrap",
 
   "markdown.copy": "Copy",
 } as const
diff --git a/packages/ui/src/lib/i18n/messages/es/markdown.ts b/packages/ui/src/lib/i18n/messages/es/markdown.ts
index f92d46b97..f0b89ac0c 100644
--- a/packages/ui/src/lib/i18n/messages/es/markdown.ts
+++ b/packages/ui/src/lib/i18n/messages/es/markdown.ts
@@ -2,6 +2,8 @@ export const markdownMessages = {
   "markdown.codeBlock.copy.label": "Copiar",
   "markdown.codeBlock.copy.copied": "¡Copiado!",
   "markdown.codeBlock.copy.failed": "Error",
+  "markdown.codeBlock.wrap.enable": "Activar ajuste de línea",
+  "markdown.codeBlock.wrap.disable": "Desactivar ajuste de línea",
 
   "markdown.copy": "Copiar",
 } as const
diff --git a/packages/ui/src/lib/i18n/messages/fr/markdown.ts b/packages/ui/src/lib/i18n/messages/fr/markdown.ts
index 42a6915a5..c8766d120 100644
--- a/packages/ui/src/lib/i18n/messages/fr/markdown.ts
+++ b/packages/ui/src/lib/i18n/messages/fr/markdown.ts
@@ -2,6 +2,8 @@ export const markdownMessages = {
   "markdown.codeBlock.copy.label": "Copier",
   "markdown.codeBlock.copy.copied": "Copié !",
   "markdown.codeBlock.copy.failed": "Échec",
+  "markdown.codeBlock.wrap.enable": "Activer le retour à la ligne",
+  "markdown.codeBlock.wrap.disable": "Désactiver le retour à la ligne",
 
   "markdown.copy": "Copier",
 } as const
diff --git a/packages/ui/src/lib/i18n/messages/he/markdown.ts b/packages/ui/src/lib/i18n/messages/he/markdown.ts
index 5505c65bb..bfa236820 100644
--- a/packages/ui/src/lib/i18n/messages/he/markdown.ts
+++ b/packages/ui/src/lib/i18n/messages/he/markdown.ts
@@ -2,6 +2,8 @@ export const markdownMessages = {
   "markdown.codeBlock.copy.label": "העתק",
   "markdown.codeBlock.copy.copied": "הועתק!",
   "markdown.codeBlock.copy.failed": "נכשל",
+  "markdown.codeBlock.wrap.enable": "הפעל גלישת שורות",
+  "markdown.codeBlock.wrap.disable": "כבה גלישת שורות",
 
   "markdown.copy": "העתק",
 } as const
diff --git a/packages/ui/src/lib/i18n/messages/ja/markdown.ts b/packages/ui/src/lib/i18n/messages/ja/markdown.ts
index 786f471cb..e8f1cfafc 100644
--- a/packages/ui/src/lib/i18n/messages/ja/markdown.ts
+++ b/packages/ui/src/lib/i18n/messages/ja/markdown.ts
@@ -2,6 +2,8 @@ export const markdownMessages = {
   "markdown.codeBlock.copy.label": "コピー",
   "markdown.codeBlock.copy.copied": "コピーしました!",
   "markdown.codeBlock.copy.failed": "失敗",
+  "markdown.codeBlock.wrap.enable": "折り返しを有効にする",
+  "markdown.codeBlock.wrap.disable": "折り返しを無効にする",
 
   "markdown.copy": "コピー",
 } as const
diff --git a/packages/ui/src/lib/i18n/messages/ne/markdown.ts b/packages/ui/src/lib/i18n/messages/ne/markdown.ts
index 842ceff7b..defe0b095 100644
--- a/packages/ui/src/lib/i18n/messages/ne/markdown.ts
+++ b/packages/ui/src/lib/i18n/messages/ne/markdown.ts
@@ -2,6 +2,8 @@ export const markdownMessages = {
   "markdown.codeBlock.copy.label": "प्रतिलिपि गर्नुहोस्",
   "markdown.codeBlock.copy.copied": "प्रतिलिपि गरियो!",
   "markdown.codeBlock.copy.failed": "असफल",
+  "markdown.codeBlock.wrap.enable": "लाइन र्‍याप सक्षम गर्नुहोस्",
+  "markdown.codeBlock.wrap.disable": "लाइन र्‍याप असक्षम गर्नुहोस्",
 
   "markdown.copy": "प्रतिलिपि गर्नुहोस्",
 } as const
diff --git a/packages/ui/src/lib/i18n/messages/ru/markdown.ts b/packages/ui/src/lib/i18n/messages/ru/markdown.ts
index 1c4050380..ee4211f2f 100644
--- a/packages/ui/src/lib/i18n/messages/ru/markdown.ts
+++ b/packages/ui/src/lib/i18n/messages/ru/markdown.ts
@@ -2,6 +2,8 @@ export const markdownMessages = {
   "markdown.codeBlock.copy.label": "Копировать",
   "markdown.codeBlock.copy.copied": "Скопировано!",
   "markdown.codeBlock.copy.failed": "Не удалось",
+  "markdown.codeBlock.wrap.enable": "Включить перенос строк",
+  "markdown.codeBlock.wrap.disable": "Отключить перенос строк",
 
   "markdown.copy": "Копировать",
 } as const
diff --git a/packages/ui/src/lib/i18n/messages/zh-Hans/markdown.ts b/packages/ui/src/lib/i18n/messages/zh-Hans/markdown.ts
index 0bae28249..dfcb3fe53 100644
--- a/packages/ui/src/lib/i18n/messages/zh-Hans/markdown.ts
+++ b/packages/ui/src/lib/i18n/messages/zh-Hans/markdown.ts
@@ -2,6 +2,8 @@ export const markdownMessages = {
   "markdown.codeBlock.copy.label": "复制",
   "markdown.codeBlock.copy.copied": "已复制！",
   "markdown.codeBlock.copy.failed": "失败",
+  "markdown.codeBlock.wrap.enable": "启用自动换行",
+  "markdown.codeBlock.wrap.disable": "禁用自动换行",
 
   "markdown.copy": "复制",
 } as const
diff --git a/packages/ui/src/lib/markdown.ts b/packages/ui/src/lib/markdown.ts
index 50b19161c..9d40506ae 100644
--- a/packages/ui/src/lib/markdown.ts
+++ b/packages/ui/src/lib/markdown.ts
@@ -14,9 +14,11 @@ let currentTheme: "light" | "dark" = "light"
 let isInitialized = false
 let highlightSuppressed = false
 let escapeRawHtmlEnabled = false
+let defaultCodeBlockWrapEnabled = true
 let rendererSetup = false
 let shikiModulePromise: Promise<typeof import("shiki/bundle/full")> | null = null
 let bundledLanguagesCache: typeof import("shiki/bundle/full")["bundledLanguages"] | null = null
+const codeBlockRenderOccurrences = new Map<string, number>()
 
 // Dollar-delimited math is handled by marked-katex-extension; bracket delimiters
 // use the small parser-native rules registered in setupRenderer.
@@ -178,6 +180,19 @@ function sanitizeRawHtmlFragment(html: string): string {
   return template.innerHTML
 }
 
+function hashString(value: string): string {
+  let hash = 2166136261
+  for (let index = 0; index < value.length; index++) {
+    hash ^= value.charCodeAt(index)
+    hash = Math.imul(hash, 16777619)
+  }
+  return (hash >>> 0).toString(16)
+}
+
+function resetCodeBlockRenderState() {
+  codeBlockRenderOccurrences.clear()
+}
+
 // Track loaded languages and queue for on-demand loading
 const loadedLanguages = new Set<string>()
 const queuedLanguages = new Set<string>()
@@ -507,29 +522,50 @@ function setupRenderer(isDark: boolean) {
 
     // Use "text" as default when no language is specified
     const resolvedLang = lang && lang.trim() ? lang.trim() : "text"
+    const occurrenceBaseKey = `${resolvedLang}\u0000${decodedCode}`
+    const occurrence = codeBlockRenderOccurrences.get(occurrenceBaseKey) ?? 0
+    codeBlockRenderOccurrences.set(occurrenceBaseKey, occurrence + 1)
+    const codeBlockKey = hashString(`${occurrenceBaseKey}\u0000${occurrence}`)
     const escapedLang = escapeHtml(resolvedLang)
     const copyLabel = escapeHtml(tGlobal("markdown.copy"))
+    const defaultWrapEnabled = defaultCodeBlockWrapEnabled
+    const wrapLabel = escapeHtml(tGlobal(defaultWrapEnabled ? "markdown.codeBlock.wrap.disable" : "markdown.codeBlock.wrap.enable"))
+    const wrapActiveClass = defaultWrapEnabled ? " active" : ""
+    const wrapPressed = defaultWrapEnabled ? "true" : "false"
 
     const header = `
  <div class="code-block-header">
    <span class="code-block-language">${escapedLang}</span>
-   <button class="code-block-copy" data-code="${encodedCode}">
-    <svg class="copy-icon" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
-      <rect x="9" y="9" width="13" height="13" rx="2" ry="2"></rect>
-      <path d="M5 15H4a2 2 0 0 1-2-2V4a2 2 0 0 1 2-2h9a2 2 0 0 1 2 2v1"></path>
-     </svg>
-    <span class="copy-text">${copyLabel}</span>
-   </button>
- </div>
- `.trim()
+   <span class="code-block-actions">
+    <button type="button" class="code-block-wrap${wrapActiveClass}" data-code-block-key="${codeBlockKey}" aria-pressed="${wrapPressed}" aria-label="${wrapLabel}" title="${wrapLabel}">
+     <svg class="wrap-icon" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
+       <path d="M3 6h18"></path>
+       <path d="M3 12h15a3 3 0 1 1 0 6h-4"></path>
+       <path d="m16 16-2 2 2 2"></path>
+       <path d="M3 18h7"></path>
+      </svg>
+     <span class="wrap-text">${wrapLabel}</span>
+    </button>
+    <button type="button" class="code-block-copy" data-code="${encodedCode}">
+     <svg class="copy-icon" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
+       <rect x="9" y="9" width="13" height="13" rx="2" ry="2"></rect>
+       <path d="M5 15H4a2 2 0 0 1-2-2V4a2 2 0 0 1 2-2h9a2 2 0 0 1 2 2v1"></path>
+      </svg>
+     <span class="copy-text">${copyLabel}</span>
+    </button>
+   </span>
+  </div>
+  `.trim()
+
+    const renderCodeBlock = (body: string) => `<div class="markdown-code-block" data-language="${escapedLang}" data-code="${encodedCode}" data-code-block-key="${codeBlockKey}" data-wrap-lines="${defaultWrapEnabled ? "true" : "false"}">${header}${body}</div>`
 
     if (highlightSuppressed) {
-      return `<div class="markdown-code-block" data-language="${escapedLang}" data-code="${encodedCode}">${header}<pre><code class="language-${escapedLang}">${escapeHtml(decodedCode)}</code></pre></div>`
+      return renderCodeBlock(`<pre><code class="language-${escapedLang}">${escapeHtml(decodedCode)}</code></pre>`)
     }
 
     // Skip highlighting for "text" language or when highlighter is not available
     if (resolvedLang === "text" || !highlighter) {
-      return `<div class="markdown-code-block" data-language="${escapedLang}" data-code="${encodedCode}">${header}<pre><code>${escapeHtml(decodedCode)}</code></pre></div>`
+      return renderCodeBlock(`<pre><code>${escapeHtml(decodedCode)}</code></pre>`)
     }
 
     // Resolve language and check if it's loaded
@@ -538,23 +574,23 @@ function setupRenderer(isDark: boolean) {
 
     // Skip highlighting for "text" aliases
     if (langKey === "text" || raw === "text") {
-      return `<div class="markdown-code-block" data-language="${escapedLang}" data-code="${encodedCode}">${header}<pre><code class="language-${escapedLang}">${escapeHtml(decodedCode)}</code></pre></div>`
+      return renderCodeBlock(`<pre><code class="language-${escapedLang}">${escapeHtml(decodedCode)}</code></pre>`)
     }
 
     // Use highlighting if language is loaded, otherwise fall back to plain code
     if (loadedLanguages.has(langKey)) {
       try {
-         const html = highlighter!.codeToHtml(decodedCode, {
-           lang: langKey,
-           theme: currentTheme === "dark" ? "github-dark" : "github-light-high-contrast",
-         })
-        return `<div class="markdown-code-block" data-language="${escapedLang}" data-code="${encodedCode}">${header}${html}</div>`
+        const html = highlighter!.codeToHtml(decodedCode, {
+          lang: langKey,
+          theme: currentTheme === "dark" ? "github-dark" : "github-light-high-contrast",
+        })
+        return renderCodeBlock(html)
       } catch {
         // Fall through to plain code if highlighting fails
       }
     }
 
-    return `<div class="markdown-code-block" data-language="${escapedLang}" data-code="${encodedCode}">${header}<pre><code class="language-${escapedLang}">${escapeHtml(decodedCode)}</code></pre></div>`
+    return renderCodeBlock(`<pre><code class="language-${escapedLang}">${escapeHtml(decodedCode)}</code></pre>`)
   }
 
   renderer.link = (href: string, title: string | null | undefined, text: string) => {
@@ -599,6 +635,7 @@ export async function renderMarkdown(
   options?: {
     suppressHighlight?: boolean
     escapeRawHtml?: boolean
+    defaultCodeBlockWrap?: boolean
   },
 ): Promise<string> {
   if (!isInitialized) {
@@ -608,6 +645,7 @@ export async function renderMarkdown(
 
   const suppressHighlight = options?.suppressHighlight ?? false
   const escapeRawHtml = options?.escapeRawHtml ?? false
+  const defaultCodeBlockWrap = options?.defaultCodeBlockWrap ?? true
   const decoded = decodeHtmlEntities(content)
 
   if (!suppressHighlight) {
@@ -617,15 +655,20 @@ export async function renderMarkdown(
 
   const previousSuppressed = highlightSuppressed
   const previousEscapeRawHtml = escapeRawHtmlEnabled
+  const previousDefaultCodeBlockWrap = defaultCodeBlockWrapEnabled
   highlightSuppressed = suppressHighlight
   escapeRawHtmlEnabled = escapeRawHtml
+  defaultCodeBlockWrapEnabled = defaultCodeBlockWrap
 
   try {
     // Proceed to parse immediately - highlighting will be available on next render
+    resetCodeBlockRenderState()
     return marked.parse(decoded) as Promise<string>
   } finally {
+    resetCodeBlockRenderState()
     highlightSuppressed = previousSuppressed
     escapeRawHtmlEnabled = previousEscapeRawHtml
+    defaultCodeBlockWrapEnabled = previousDefaultCodeBlockWrap
   }
 }
 
diff --git a/packages/ui/src/styles/markdown.css b/packages/ui/src/styles/markdown.css
index 5e95c4719..40a488aa7 100644
--- a/packages/ui/src/styles/markdown.css
+++ b/packages/ui/src/styles/markdown.css
@@ -242,6 +242,15 @@
     border-bottom: 1px solid var(--border-base);
   }
 
+  .code-block-actions {
+    display: inline-flex;
+    align-items: center;
+    gap: var(--space-xs);
+    flex: 0 0 auto;
+    margin-inline-start: auto;
+    margin-inline-end: var(--space-sm);
+  }
+
   .code-block-language {
     font-family: var(--message-part-header-font-family);
     color: var(--text-primary);
@@ -252,7 +261,8 @@
     line-height: var(--message-part-header-title-line-height);
   }
 
-  .code-block-copy {
+  .code-block-copy,
+  .code-block-wrap {
     display: inline-flex;
     align-items: center;
     justify-content: center;
@@ -262,28 +272,30 @@
     padding: 0;
     background-color: transparent;
     border: none;
-    border-radius: 0.25rem;
+    border-radius: 0;
     cursor: pointer;
     color: var(--text-secondary);
     flex: 0 0 auto;
     transition:
       background-color 150ms ease,
       color 150ms ease;
-    margin-inline-start: auto;
-    margin-inline-end: var(--space-sm);
   }
 
-  .code-block-copy:hover {
+  .code-block-copy:hover,
+  .code-block-wrap:hover,
+  .code-block-wrap.active {
     background-color: transparent;
     color: var(--text-primary);
   }
 
-  .code-block-copy .copy-icon {
+  .code-block-copy .copy-icon,
+  .code-block-wrap .wrap-icon {
     width: 0.875rem;
     height: 0.875rem;
   }
 
-  .code-block-copy .copy-text {
+  .code-block-copy .copy-text,
+  .code-block-wrap .wrap-text {
     position: absolute;
     width: 1px;
     height: 1px;
@@ -311,4 +323,14 @@
     background: transparent !important;
     padding: 0 !important;
   }
+
+  .markdown-code-block[data-wrap-lines="true"] pre,
+  .markdown-code-block[data-wrap-lines="true"] code,
+  .markdown-code-block[data-wrap-lines="true"] pre.shiki,
+  .markdown-code-block[data-wrap-lines="true"] pre.shiki code,
+  .markdown-code-block[data-wrap-lines="true"] .shiki {
+    white-space: pre-wrap !important;
+    word-break: break-word;
+    overflow-wrap: anywhere;
+  }
 }