diff --git a/packages/dify-ui/src/toast/__tests__/index.spec.tsx b/packages/dify-ui/src/toast/__tests__/index.spec.tsx
index 0b06c6e1be8..7e9227e362e 100644
--- a/packages/dify-ui/src/toast/__tests__/index.spec.tsx
+++ b/packages/dify-ui/src/toast/__tests__/index.spec.tsx
@@ -69,6 +69,28 @@ describe('@langgenius/dify-ui/toast', () => {
     dispatchToastMouseOut(viewport)
   })
 
+  it('should clamp varying-height toasts to the frontmost stack height when collapsed', async () => {
+    const screen = await render(<ToastHost />)
+
+    toast.info('Long background toast', {
+      description: 'This longer toast intentionally spans multiple lines so it would overflow the collapsed stack without matching the frontmost toast height.',
+    })
+    toast.success('Short front toast', {
+      description: 'Short message.',
+    })
+
+    await expect.element(screen.getByText('Short front toast')).toBeInTheDocument()
+    await expect.element(screen.getByText('Long background toast')).toBeInTheDocument()
+    await expect.element(screen.getByRole('region', { name: 'Notifications' })).toHaveAttribute('aria-live', 'polite')
+    await expect.element(screen.getByRole('dialog', { name: 'Short front toast' })).toBeInTheDocument()
+    await expect.element(screen.getByRole('dialog', { name: 'Long background toast' })).toBeInTheDocument()
+
+    const longToastContent = screen.getByText('Long background toast').element().closest('[class*="transition-opacity"]')
+    expect(longToastContent).toHaveAttribute('data-behind')
+    expect(longToastContent).toHaveClass('h-full')
+    expect(longToastContent?.parentElement).toHaveClass('h-full')
+  })
+
   it('should render a neutral toast when called directly', async () => {
     const screen = await render(<ToastHost />)
 
diff --git a/packages/dify-ui/src/toast/index.stories.tsx b/packages/dify-ui/src/toast/index.stories.tsx
index 772d0c456ce..b0ead00c9fd 100644
--- a/packages/dify-ui/src/toast/index.stories.tsx
+++ b/packages/dify-ui/src/toast/index.stories.tsx
@@ -1,5 +1,6 @@
 import type { Meta, StoryObj } from '@storybook/react-vite'
 import type { ReactNode } from 'react'
+import { useRef } from 'react'
 import { toast, ToastHost } from '.'
 
 const buttonClassName = 'rounded-lg border border-divider-subtle bg-components-button-secondary-bg px-3 py-2 text-sm text-text-secondary shadow-xs transition-colors hover:bg-state-base-hover'
@@ -117,6 +118,15 @@ const StackExamples = () => {
     })
   }
 
+  const createVaryingHeightStack = () => {
+    toast.info('Long background toast', {
+      description: 'This longer toast intentionally spans multiple lines so the collapsed stack can be checked against the shorter frontmost toast height without panel overflow.',
+    })
+    toast.success('Short front toast', {
+      description: 'Short message.',
+    })
+  }
+
   return (
     <ExampleCard
       eyebrow="Stack"
@@ -129,6 +139,9 @@ const StackExamples = () => {
       <button type="button" className={buttonClassName} onClick={createBurst}>
         Stress the stack
       </button>
+      <button type="button" className={buttonClassName} onClick={createVaryingHeightStack}>
+        Varying heights
+      </button>
     </ExampleCard>
   )
 }
@@ -192,11 +205,14 @@ const PromiseExamples = () => {
 
 const ActionExamples = () => {
   const createActionToast = () => {
-    toast.warning('Project archived', {
+    let archivedToastId = ''
+    archivedToastId = toast.warning('Project archived', {
       description: 'You can restore it from workspace settings for the next 30 days.',
+      timeout: 10000,
       actionProps: {
         children: 'Undo',
         onClick: () => {
+          toast.dismiss(archivedToastId)
           toast.success('Project restored', {
             description: 'The workspace is active again.',
           })
@@ -233,6 +249,32 @@ const ActionExamples = () => {
   )
 }
 
+const DeduplicateExamples = () => {
+  const saveCountRef = useRef(0)
+
+  const saveDraft = () => {
+    saveCountRef.current += 1
+    toast.success('Draft saved', {
+      id: 'draft-save-status',
+      description: saveCountRef.current === 1
+        ? 'Click again while this toast is visible to update the same mounted toast.'
+        : `Same toast updated ${saveCountRef.current} times.`,
+    })
+  }
+
+  return (
+    <ExampleCard
+      eyebrow="Deduplicated"
+      title="Same-id upsert"
+      description="Matches the Base UI deduplicated toast example: repeated triggers use a stable id, so the visible toast is updated instead of adding another stack item."
+    >
+      <button type="button" className={buttonClassName} onClick={saveDraft}>
+        Save draft
+      </button>
+    </ExampleCard>
+  )
+}
+
 const UpdateExamples = () => {
   const createUpdatableToast = () => {
     const toastId = toast.info('Import started', {
@@ -292,6 +334,7 @@ const ToastDocsDemo = () => {
             <StackExamples />
             <PromiseExamples />
             <ActionExamples />
+            <DeduplicateExamples />
             <UpdateExamples />
           </div>
         </div>
diff --git a/packages/dify-ui/src/toast/index.tsx b/packages/dify-ui/src/toast/index.tsx
index 269e18fa658..cab9841a327 100644
--- a/packages/dify-ui/src/toast/index.tsx
+++ b/packages/dify-ui/src/toast/index.tsx
@@ -166,12 +166,12 @@ function ToastCard({
         'after:pointer-events-auto after:absolute after:top-full after:left-0 after:h-[calc(var(--toast-gap)+1px)] after:w-full after:content-[\'\']',
       )}
     >
-      <div className="relative overflow-hidden rounded-xl border border-components-panel-border bg-components-panel-bg-blur shadow-lg shadow-shadow-shadow-5 backdrop-blur-[5px]">
+      <div className="relative h-full overflow-hidden rounded-xl border border-components-panel-border bg-components-panel-bg-blur shadow-lg shadow-shadow-shadow-5 backdrop-blur-[5px]">
         <div
           aria-hidden="true"
           className={cn('absolute -inset-px bg-linear-to-r opacity-40', getToneGradientClasses(toastType))}
         />
-        <BaseToast.Content className="relative flex items-start gap-1 overflow-hidden p-3 transition-opacity duration-200 data-behind:opacity-0 data-expanded:opacity-100 motion-reduce:transition-none">
+        <BaseToast.Content className="relative flex h-full items-start gap-1 overflow-hidden p-3 transition-opacity duration-200 data-behind:opacity-0 data-expanded:opacity-100 motion-reduce:transition-none">
           <div className="flex shrink-0 items-center justify-center p-0.5">
             <ToastIcon type={toastType} />
           </div>