diff --git a/packages/dify-ui/README.md b/packages/dify-ui/README.md
index 06db2d0f41..1833eb4ecd 100644
--- a/packages/dify-ui/README.md
+++ b/packages/dify-ui/README.md
@@ -166,8 +166,23 @@ See `[web/docs/overlay.md](../../web/docs/overlay.md)` for the web app overlay b
 
 - `pnpm -C packages/dify-ui test` — Vitest unit tests for primitives.
 - `pnpm -C packages/dify-ui storybook` — Storybook on the default port. Each primitive has `index.stories.tsx`.
+- `pnpm -C packages/dify-ui test:storybook` — Storybook component tests in Vitest browser mode. Stories without `play` are render and a11y smoke tests; stories with `play` should cover public UI contracts such as opening overlays, keyboard navigation, disabled/loading guards, form submission, and controlled state updates.
 - `pnpm -C packages/dify-ui type-check` — `tsgo --noEmit` for this package only.
 
+### Test Boundary
+
+Use Storybook tests for behavior that belongs to the documented component example:
+visible state changes, user interaction, keyboard paths, overlay open/close flows,
+and accessibility-facing semantics. Keep regular Vitest unit tests for lower-level
+wrapper contracts such as class variants, Base UI passthrough props, hidden input
+serialization, data attribute hooks, store behavior, and edge cases that do not
+need a full story.
+
+Storybook accessibility testing stays enabled globally with `a11y.test = 'error'`.
+If a story is temporarily marked `todo`, keep the exception local to that story
+and do not treat an interaction `play` test as a replacement for fixing the
+underlying accessibility issue.
+
 ### Disabling Animations In Tests
 
 Base UI can wait for `element.getAnimations()` to finish before it unmounts overlays, panels, and transition-driven components. Browser-based test runners can make that timing unstable, especially when tests assert final DOM state rather than animation behavior.
diff --git a/packages/dify-ui/src/alert-dialog/index.stories.tsx b/packages/dify-ui/src/alert-dialog/index.stories.tsx
index e56d6b942f..c8dcc6ac53 100644
--- a/packages/dify-ui/src/alert-dialog/index.stories.tsx
+++ b/packages/dify-ui/src/alert-dialog/index.stories.tsx
@@ -1,5 +1,6 @@
 import type { Meta, StoryObj } from '@storybook/react-vite'
 import * as React from 'react'
+import { expect, waitFor, within } from 'storybook/test'
 import {
   AlertDialog,
   AlertDialogActions,
@@ -55,6 +56,21 @@ export const Default: Story = {
       </AlertDialogContent>
     </AlertDialog>
   ),
+  play: async ({ canvas, canvasElement, userEvent }) => {
+    const body = within(canvasElement.ownerDocument.body)
+
+    await userEvent.click(canvas.getByRole('button', { name: 'Delete project' }))
+
+    const dialog = body.getByRole('alertdialog', { name: 'Delete project?' })
+    await waitFor(async () => {
+      await expect(dialog).toBeVisible()
+    })
+
+    await userEvent.click(body.getByRole('button', { name: 'Cancel' }))
+    await waitFor(async () => {
+      await expect(body.queryByRole('alertdialog', { name: 'Delete project?' })).not.toBeInTheDocument()
+    })
+  },
 }
 
 export const NonDestructive: Story = {
diff --git a/packages/dify-ui/src/button/index.stories.tsx b/packages/dify-ui/src/button/index.stories.tsx
index de3fef48bf..91a1d38c2d 100644
--- a/packages/dify-ui/src/button/index.stories.tsx
+++ b/packages/dify-ui/src/button/index.stories.tsx
@@ -1,5 +1,6 @@
 import type { Meta, StoryObj } from '@storybook/react-vite'
 import * as React from 'react'
+import { expect, fn } from 'storybook/test'
 
 import { Button } from '.'
 
@@ -90,8 +91,21 @@ export const Loading: Story = {
   args: {
     variant: 'primary',
     loading: true,
+    onClick: fn(),
     children: 'Loading Button',
   },
+  play: async ({ args, canvas, userEvent }) => {
+    const button = canvas.getByRole('button', { name: 'Loading Button' })
+
+    await expect(button).toHaveAttribute('aria-disabled', 'true')
+    await expect(button).toHaveAttribute('aria-busy', 'true')
+
+    button.focus()
+    await expect(button).toHaveFocus()
+
+    await userEvent.click(button)
+    await expect(args.onClick).not.toHaveBeenCalled()
+  },
   parameters: {
     docs: {
       description: {
diff --git a/packages/dify-ui/src/combobox/index.stories.tsx b/packages/dify-ui/src/combobox/index.stories.tsx
index a1c1badff9..1c8021811c 100644
--- a/packages/dify-ui/src/combobox/index.stories.tsx
+++ b/packages/dify-ui/src/combobox/index.stories.tsx
@@ -2,6 +2,7 @@ import type { Meta, StoryObj } from '@storybook/react-vite'
 import type { Virtualizer } from '@tanstack/react-virtual'
 import { useVirtualizer } from '@tanstack/react-virtual'
 import * as React from 'react'
+import { expect } from 'storybook/test'
 import {
   Combobox,
   ComboboxChip,
@@ -768,6 +769,15 @@ const MultipleChipsDemo = () => {
 
 export const MultipleChips: Story = {
   render: () => <MultipleChipsDemo />,
+  play: async ({ canvas, userEvent }) => {
+    await expect(canvas.getByText('Maya Chen')).toBeVisible()
+    await expect(canvas.getByText('Liam Brooks')).toBeVisible()
+
+    await userEvent.click(canvas.getByRole('button', { name: 'Remove Maya Chen' }))
+
+    await expect(canvas.queryByText('Maya Chen')).not.toBeInTheDocument()
+    await expect(canvas.getByText('Liam Brooks')).toBeVisible()
+  },
 }
 
 export const VirtualizedLongList: Story = {
diff --git a/packages/dify-ui/src/dialog/index.stories.tsx b/packages/dify-ui/src/dialog/index.stories.tsx
index cd101017f2..e70cc2465d 100644
--- a/packages/dify-ui/src/dialog/index.stories.tsx
+++ b/packages/dify-ui/src/dialog/index.stories.tsx
@@ -1,5 +1,6 @@
 import type { Meta, StoryObj } from '@storybook/react-vite'
 import * as React from 'react'
+import { expect, waitFor, within } from 'storybook/test'
 import {
   Dialog,
   DialogCloseButton,
@@ -66,6 +67,22 @@ export const Default: Story = {
       </DialogContent>
     </Dialog>
   ),
+  play: async ({ canvas, canvasElement, userEvent }) => {
+    const body = within(canvasElement.ownerDocument.body)
+
+    await userEvent.click(canvas.getByRole('button', { name: 'Open dialog' }))
+
+    const dialog = body.getByRole('dialog', { name: 'Invite collaborators' })
+    await waitFor(async () => {
+      await expect(dialog).toBeVisible()
+    })
+    await expect(body.getByRole('textbox', { name: 'Email address' })).toBeVisible()
+
+    await userEvent.click(body.getByRole('button', { name: 'Close' }))
+    await waitFor(async () => {
+      await expect(body.queryByRole('dialog', { name: 'Invite collaborators' })).not.toBeInTheDocument()
+    })
+  },
 }
 
 export const WithoutCloseButton: Story = {
diff --git a/packages/dify-ui/src/file-tree/index.stories.tsx b/packages/dify-ui/src/file-tree/index.stories.tsx
index 5545ad9b8e..a75e40aa65 100644
--- a/packages/dify-ui/src/file-tree/index.stories.tsx
+++ b/packages/dify-ui/src/file-tree/index.stories.tsx
@@ -1,6 +1,7 @@
 import type { Meta, StoryObj } from '@storybook/react-vite'
 import type { FileTreeIconType } from '.'
 import * as React from 'react'
+import { expect } from 'storybook/test'
 import {
   FileTreeBadge,
   FileTreeFile,
@@ -330,6 +331,19 @@ function VisualStates() {
 
 export const Default: Story = {
   render: () => <ComposedFileTree />,
+  play: async ({ canvas, userEvent }) => {
+    const srcFolder = canvas.getByRole('button', { name: 'src' })
+
+    await expect(canvas.getByRole('button', { name: 'components' })).toBeVisible()
+
+    await userEvent.click(srcFolder)
+    await expect(srcFolder).toHaveAttribute('aria-expanded', 'false')
+    await expect(canvas.queryByRole('button', { name: 'components' })).not.toBeInTheDocument()
+
+    await userEvent.click(srcFolder)
+    await expect(srcFolder).toHaveAttribute('aria-expanded', 'true')
+    await expect(canvas.getByRole('button', { name: 'components' })).toBeVisible()
+  },
 }
 
 export const DataDriven: Story = {
diff --git a/packages/dify-ui/src/pagination/index.stories.tsx b/packages/dify-ui/src/pagination/index.stories.tsx
index a5419da798..6ffab6bfee 100644
--- a/packages/dify-ui/src/pagination/index.stories.tsx
+++ b/packages/dify-ui/src/pagination/index.stories.tsx
@@ -1,5 +1,6 @@
 import type { Meta, StoryObj } from '@storybook/react-vite'
 import * as React from 'react'
+import { expect } from 'storybook/test'
 import {
   Pagination,
   PaginationSkeleton,
@@ -77,6 +78,15 @@ type Story = StoryObj<typeof meta>
 
 export const Playground: Story = {
   render: () => <PaginationDemo />,
+  play: async ({ canvas, userEvent }) => {
+    await expect(canvas.getByRole('button', { name: 'Edit page number, current page 2 of 200' })).toBeVisible()
+
+    await userEvent.click(canvas.getByRole('button', { name: 'Next page' }))
+    await expect(canvas.getByRole('button', { name: 'Edit page number, current page 3 of 200' })).toBeVisible()
+
+    await userEvent.click(canvas.getByRole('button', { name: '50' }))
+    await expect(canvas.getByRole('button', { name: '50' })).toHaveAttribute('aria-pressed', 'true')
+  },
   parameters: {
     a11y: {
       test: 'todo',
diff --git a/packages/dify-ui/src/select/index.stories.tsx b/packages/dify-ui/src/select/index.stories.tsx
index 64cd2b8649..7560257201 100644
--- a/packages/dify-ui/src/select/index.stories.tsx
+++ b/packages/dify-ui/src/select/index.stories.tsx
@@ -1,5 +1,6 @@
 import type { Meta, StoryObj } from '@storybook/react-vite'
 import * as React from 'react'
+import { expect, waitFor, within } from 'storybook/test'
 import {
   Select,
   SelectContent,
@@ -19,6 +20,8 @@ const triggerWidth = 'w-64'
 const cityItems = [
   { label: 'Seattle', value: 'seattle' },
   { label: 'New York', value: 'new-york' },
+  { label: 'Tokyo', value: 'tokyo' },
+  { label: 'Paris', value: 'paris' },
 ]
 
 const meta = {
@@ -41,11 +44,11 @@ type Story = StoryObj<typeof meta>
 export const Default: Story = {
   render: () => (
     <div className={triggerWidth}>
-      <Select defaultValue="seattle">
+      <Select items={cityItems} defaultValue="seattle">
         <SelectTrigger aria-label="City">
           <SelectValue placeholder="Select a city" />
         </SelectTrigger>
-        <SelectContent>
+        <SelectContent listProps={{ 'aria-label': 'City options' }}>
           <SelectItem value="seattle">
             <SelectItemText>Seattle</SelectItemText>
             <SelectItemIndicator />
@@ -66,6 +69,27 @@ export const Default: Story = {
       </Select>
     </div>
   ),
+  play: async ({ canvas, canvasElement, userEvent }) => {
+    const trigger = canvas.getByRole('combobox', { name: 'City' })
+    const body = within(canvasElement.ownerDocument.body)
+
+    await expect(trigger).toHaveTextContent('Seattle')
+
+    trigger.focus()
+    await userEvent.keyboard('{ArrowDown}')
+
+    await waitFor(async () => {
+      await expect(body.getByRole('option', { name: 'Tokyo' })).toBeVisible()
+    })
+
+    await userEvent.keyboard('{ArrowDown}{ArrowDown}{Enter}')
+    await expect(trigger).toHaveTextContent('Tokyo')
+
+    await userEvent.keyboard('{Escape}')
+    await waitFor(async () => {
+      await expect(body.queryByRole('listbox', { name: 'City options' })).not.toBeInTheDocument()
+    })
+  },
 }
 
 export const WithVisibleLabel: Story = {
diff --git a/packages/dify-ui/src/switch/index.stories.tsx b/packages/dify-ui/src/switch/index.stories.tsx
index a7537b50b8..40e9ca6e51 100644
--- a/packages/dify-ui/src/switch/index.stories.tsx
+++ b/packages/dify-ui/src/switch/index.stories.tsx
@@ -1,5 +1,6 @@
 import type { Meta, StoryObj } from '@storybook/react-vite'
 import * as React from 'react'
+import { expect } from 'storybook/test'
 import { Switch, SwitchSkeleton } from '.'
 import {
   FieldDescription,
@@ -77,6 +78,17 @@ export const Default: Story = {
     checked: false,
     disabled: false,
   },
+  play: async ({ canvas, userEvent }) => {
+    const switchControl = canvas.getByRole('switch', { name: 'Enable auto retry' })
+
+    await expect(switchControl).toHaveAttribute('aria-checked', 'false')
+    await expect(canvas.getByText('Failures require manual retry.')).toBeVisible()
+
+    await userEvent.click(switchControl)
+
+    await expect(switchControl).toHaveAttribute('aria-checked', 'true')
+    await expect(canvas.getByText('Failures will retry automatically.')).toBeVisible()
+  },
 }
 
 export const DefaultOn: Story = {