diff --git a/apps/sim/app/workspace/[workspaceId]/home/components/user-input/components/prompt-editor/use-prompt-editor.test.tsx b/apps/sim/app/workspace/[workspaceId]/home/components/user-input/components/prompt-editor/use-prompt-editor.test.tsx
new file mode 100644
index 00000000000..7cd9a2281c0
--- /dev/null
+++ b/apps/sim/app/workspace/[workspaceId]/home/components/user-input/components/prompt-editor/use-prompt-editor.test.tsx
@@ -0,0 +1,246 @@
+/**
+ * @vitest-environment jsdom
+ */
+import { act, type ReactNode } from 'react'
+import { createRoot, type Root } from 'react-dom/client'
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+
+vi.mock('@/hooks/queries/skills', () => ({ useSkills: () => ({ data: [] }) }))
+vi.mock('@/hooks/queries/workflows', () => ({ useWorkflows: () => ({ data: [] }) }))
+vi.mock('@/hooks/queries/tables', () => ({ useTablesList: () => ({ data: [] }) }))
+vi.mock('@/hooks/queries/workspace-files', () => ({ useWorkspaceFiles: () => ({ data: [] }) }))
+vi.mock('@/hooks/queries/kb/knowledge', () => ({ useKnowledgeBasesQuery: () => ({ data: [] }) }))
+vi.mock('@/hooks/queries/folders', () => ({ useFolders: () => ({ data: [] }) }))
+vi.mock('@/hooks/queries/workspace-file-folders', () => ({
+  useWorkspaceFileFolders: () => ({ data: [] }),
+}))
+vi.mock('@/hooks/queries/mothership-chats', () => ({ useMothershipChats: () => ({ data: [] }) }))
+vi.mock('@/hooks/queries/schedules', () => ({ useWorkspaceSchedules: () => ({ data: [] }) }))
+vi.mock('@/hooks/queries/logs', () => ({ useLogsList: () => ({ data: undefined }) }))
+vi.mock('@/blocks/integration-matcher', () => ({
+  getIntegrationMatcher: () => ({ regex: null, byName: new Map() }),
+  listIntegrations: () => [],
+}))
+
+import type { PlusMenuHandle } from '@/app/workspace/[workspaceId]/home/components/user-input/components/constants'
+import {
+  type UsePromptEditorProps,
+  usePromptEditor,
+} from '@/app/workspace/[workspaceId]/home/components/user-input/components/prompt-editor/use-prompt-editor'
+import type { SkillsMenuHandle } from '@/app/workspace/[workspaceId]/home/components/user-input/components/skills-menu-dropdown/skills-menu-dropdown'
+
+/**
+ * Mounts `usePromptEditor` in a real React 19 root under jsdom (no
+ * `@testing-library/react` in this repo — see `hooks/queries/unsubscribe.test.tsx`
+ * for the established pattern) and wires a real `<textarea>` into its
+ * `textareaRef` so selection/caret-driven behavior (`handleSelectAdjust`,
+ * `syncMentionState`) runs exactly as it does in the rendered `PromptEditor`.
+ */
+function renderPromptEditor(props: UsePromptEditorProps) {
+  ;(globalThis as { IS_REACT_ACT_ENVIRONMENT?: boolean }).IS_REACT_ACT_ENVIRONMENT = true
+  const container = document.createElement('div')
+  document.body.appendChild(container)
+  const root: Root = createRoot(container)
+  let latest: ReturnType<typeof usePromptEditor>
+
+  function Probe() {
+    latest = usePromptEditor(props)
+    return null
+  }
+
+  function Wrapper({ children }: { children: ReactNode }) {
+    return <>{children}</>
+  }
+
+  act(() => {
+    root.render(
+      <Wrapper>
+        <Probe />
+      </Wrapper>
+    )
+  })
+
+  const textarea = document.createElement('textarea')
+  document.body.appendChild(textarea)
+  latest!.textareaRef.current = textarea
+
+  return {
+    result: () => latest,
+    textarea,
+    unmount: () => {
+      act(() => root.unmount())
+      container.remove()
+      textarea.remove()
+    },
+  }
+}
+
+/** Fires a native `input` event carrying the new value, as the textarea would on a keystroke. */
+function typeInto(textarea: HTMLTextAreaElement, value: string, caret = value.length) {
+  textarea.value = value
+  textarea.setSelectionRange(caret, caret)
+  textarea.dispatchEvent(new Event('input', { bubbles: true }))
+}
+
+describe('usePromptEditor mention menu dismissal', () => {
+  let openMenu: PlusMenuHandle
+
+  beforeEach(() => {
+    openMenu = {
+      open: vi.fn(),
+      close: vi.fn(),
+      moveActive: vi.fn(),
+      selectActive: vi.fn(() => false),
+    }
+  })
+
+  afterEach(() => {
+    vi.clearAllMocks()
+  })
+
+  it('reopens the menu while the user keeps typing an unmatched mention', () => {
+    const { result, textarea, unmount } = renderPromptEditor({ workspaceId: 'ws-1' })
+    result().plusMenuRef.current = openMenu
+
+    act(() => {
+      typeInto(textarea, '@f')
+      result().handleInputChange({
+        target: textarea,
+        currentTarget: textarea,
+      } as unknown as React.ChangeEvent<HTMLTextAreaElement>)
+    })
+
+    expect(result().mentionQuery).toBe('f')
+    expect(openMenu.open).toHaveBeenCalledTimes(1)
+
+    unmount()
+  })
+
+  it('does not reopen after the user clicks away, even if the caret lands back inside the open mention', () => {
+    const { result, textarea, unmount } = renderPromptEditor({ workspaceId: 'ws-1' })
+    result().plusMenuRef.current = openMenu
+
+    act(() => {
+      typeInto(textarea, '@f')
+      result().handleInputChange({
+        target: textarea,
+        currentTarget: textarea,
+      } as unknown as React.ChangeEvent<HTMLTextAreaElement>)
+    })
+    expect(result().mentionQuery).toBe('f')
+
+    act(() => {
+      result().handlePlusMenuClose()
+    })
+    expect(result().mentionQuery).toBeNull()
+
+    act(() => {
+      textarea.setSelectionRange(2, 2)
+      result().handleSelectAdjust()
+    })
+
+    expect(result().mentionQuery).toBeNull()
+    expect(openMenu.open).toHaveBeenCalledTimes(1)
+
+    unmount()
+  })
+
+  it('lets a further keystroke reopen the same mention after a dismiss', () => {
+    const { result, textarea, unmount } = renderPromptEditor({ workspaceId: 'ws-1' })
+    result().plusMenuRef.current = openMenu
+
+    act(() => {
+      typeInto(textarea, '@f')
+      result().handleInputChange({
+        target: textarea,
+        currentTarget: textarea,
+      } as unknown as React.ChangeEvent<HTMLTextAreaElement>)
+    })
+    act(() => {
+      result().handlePlusMenuClose()
+    })
+    act(() => {
+      textarea.setSelectionRange(2, 2)
+      result().handleSelectAdjust()
+    })
+    expect(openMenu.open).toHaveBeenCalledTimes(1)
+
+    act(() => {
+      typeInto(textarea, '@fo', 3)
+      result().handleInputChange({
+        target: textarea,
+        currentTarget: textarea,
+      } as unknown as React.ChangeEvent<HTMLTextAreaElement>)
+    })
+
+    expect(result().mentionQuery).toBe('fo')
+    expect(openMenu.open).toHaveBeenCalledTimes(2)
+
+    unmount()
+  })
+
+  it('does not suppress a different mention typed after a dismiss', () => {
+    const { result, textarea, unmount } = renderPromptEditor({ workspaceId: 'ws-1' })
+    result().plusMenuRef.current = openMenu
+
+    act(() => {
+      typeInto(textarea, '@f')
+      result().handleInputChange({
+        target: textarea,
+        currentTarget: textarea,
+      } as unknown as React.ChangeEvent<HTMLTextAreaElement>)
+    })
+    act(() => {
+      result().handlePlusMenuClose()
+    })
+    act(() => {
+      textarea.setSelectionRange(2, 2)
+      result().handleSelectAdjust()
+    })
+    expect(openMenu.open).toHaveBeenCalledTimes(1)
+
+    act(() => {
+      typeInto(textarea, '@f done. @g', 11)
+      result().handleInputChange({
+        target: textarea,
+        currentTarget: textarea,
+      } as unknown as React.ChangeEvent<HTMLTextAreaElement>)
+    })
+
+    expect(result().mentionQuery).toBe('g')
+    expect(openMenu.open).toHaveBeenCalledTimes(2)
+
+    unmount()
+  })
+})
+
+describe('usePromptEditor toolbar slash trigger after a dismiss', () => {
+  it('still opens the skills menu when the caret sits at the start of the previously dismissed token', () => {
+    const skillsMenu: SkillsMenuHandle = {
+      open: vi.fn(),
+      close: vi.fn(),
+      moveActive: vi.fn(),
+      selectActive: vi.fn(() => false),
+    }
+    const { result, textarea, unmount } = renderPromptEditor({ workspaceId: 'ws-1' })
+    result().skillsMenuRef.current = skillsMenu
+
+    act(() => {
+      result().insertSlashTrigger()
+    })
+    expect(skillsMenu.open).toHaveBeenCalledTimes(1)
+
+    act(() => {
+      result().handleSkillsMenuClose()
+    })
+
+    act(() => {
+      textarea.setSelectionRange(0, 0)
+      result().insertSlashTrigger()
+    })
+
+    expect(skillsMenu.open).toHaveBeenCalledTimes(2)
+
+    unmount()
+  })
+})
diff --git a/apps/sim/app/workspace/[workspaceId]/home/components/user-input/components/prompt-editor/use-prompt-editor.ts b/apps/sim/app/workspace/[workspaceId]/home/components/user-input/components/prompt-editor/use-prompt-editor.ts
index b6e971c14ca..49aeededfd4 100644
--- a/apps/sim/app/workspace/[workspaceId]/home/components/user-input/components/prompt-editor/use-prompt-editor.ts
+++ b/apps/sim/app/workspace/[workspaceId]/home/components/user-input/components/prompt-editor/use-prompt-editor.ts
@@ -179,6 +179,15 @@ export function usePromptEditor({
   const slashRangeRef = useRef<{ start: number; end: number } | null>(null)
   const [slashQuery, setSlashQuery] = useState<string | null>(null)
 
+  /**
+   * Start offset of a mention/slash token most recently dismissed by the user
+   * (outside click or Escape) without a following keystroke — suppresses a
+   * single reopen of the menu for that exact token when the caret's own
+   * selection-change handler runs immediately after.
+   */
+  const dismissedMentionStartRef = useRef<number | null>(null)
+  const dismissedSlashStartRef = useRef<number | null>(null)
+
   const contextManagement = useContextManagement({ message: value, initialContexts })
   const contextManagementRef = useRef(contextManagement)
   contextManagementRef.current = contextManagement
@@ -327,9 +336,11 @@ export function usePromptEditor({
     plusMenuRef.current?.close()
     mentionRangeRef.current = null
     setMentionQuery(null)
+    dismissedMentionStartRef.current = null
     skillsMenuRef.current?.close()
     slashRangeRef.current = null
     setSlashQuery(null)
+    dismissedSlashStartRef.current = null
     if (textareaRef.current) {
       textareaRef.current.style.height = 'auto'
     }
@@ -368,6 +379,7 @@ export function usePromptEditor({
         atInsertPosRef.current = newPos
         mentionRangeRef.current = null
         setMentionQuery(null)
+        dismissedMentionStartRef.current = null
         setValueState(newValue)
       }
 
@@ -423,6 +435,7 @@ export function usePromptEditor({
         valueRef.current = newValue
         slashRangeRef.current = null
         setSlashQuery(null)
+        dismissedSlashStartRef.current = null
         setValueState(newValue)
       }
 
@@ -431,12 +444,24 @@ export function usePromptEditor({
     [textareaRef, addContextNotified]
   )
 
+  /**
+   * Only reachable via Radix's own dismiss detection (outside click /
+   * Escape) — programmatic closes (`skillsMenuRef.current?.close()`) bypass
+   * `onOpenChange` and never call this.
+   */
   const handleSkillsMenuClose = useCallback(() => {
+    dismissedSlashStartRef.current = slashRangeRef.current?.start ?? null
     slashRangeRef.current = null
     setSlashQuery(null)
   }, [])
 
+  /**
+   * Only reachable via Radix's own dismiss detection (outside click /
+   * Escape) — programmatic closes (`plusMenuRef.current?.close()`) bypass
+   * `onOpenChange` and never call this.
+   */
   const handlePlusMenuClose = useCallback(() => {
+    dismissedMentionStartRef.current = mentionRangeRef.current?.start ?? null
     atInsertPosRef.current = null
     mentionRangeRef.current = null
     setMentionQuery(null)
@@ -463,6 +488,15 @@ export function usePromptEditor({
           setMentionQuery(null)
           plusMenuRef.current?.close()
         }
+        dismissedMentionStartRef.current = null
+        return
+      }
+
+      if (active.start === dismissedMentionStartRef.current) {
+        if (mentionRangeRef.current !== null) {
+          mentionRangeRef.current = null
+          setMentionQuery(null)
+        }
         return
       }
 
@@ -491,6 +525,15 @@ export function usePromptEditor({
           setSlashQuery(null)
           skillsMenuRef.current?.close()
         }
+        dismissedSlashStartRef.current = null
+        return
+      }
+
+      if (active.start === dismissedSlashStartRef.current) {
+        if (slashRangeRef.current !== null) {
+          slashRangeRef.current = null
+          setSlashQuery(null)
+        }
         return
       }
 
@@ -530,6 +573,7 @@ export function usePromptEditor({
     setValueState(newValue)
     textarea.value = newValue
     textarea.setSelectionRange(newCaret, newCaret)
+    dismissedSlashStartRef.current = null
     syncSlashState(textarea, newValue, newCaret)
   }, [textareaRef, syncSlashState])
 
@@ -584,6 +628,8 @@ export function usePromptEditor({
       const caret = e.target.selectionStart ?? finalValue.length
       valueRef.current = finalValue
       setValueState(finalValue)
+      dismissedMentionStartRef.current = null
+      dismissedSlashStartRef.current = null
       syncMentionState(e.target, finalValue, caret)
       syncSlashState(e.target, finalValue, caret)
     },