diff --git a/__tests__/components/sprint/sprint-task-dialog-mount.test.tsx b/__tests__/components/sprint/sprint-task-dialog-mount.test.tsx
new file mode 100644
index 0000000..886dbfe
--- /dev/null
+++ b/__tests__/components/sprint/sprint-task-dialog-mount.test.tsx
@@ -0,0 +1,119 @@
+// @vitest-environment jsdom
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+import { render, screen, fireEvent, waitFor } from '@testing-library/react'
+
+vi.mock('next/navigation', () => ({ useRouter: () => ({ push: vi.fn() }) }))
+vi.mock('@/actions/tasks', () => ({
+  saveTask: vi.fn(),
+  deleteTask: vi.fn(),
+}))
+vi.mock('sonner', () => ({ toast: { success: vi.fn(), error: vi.fn() } }))
+
+import { SprintTaskDialogMount } from '@/components/sprint/sprint-task-dialog-mount'
+import { useSprintWorkspaceStore } from '@/stores/sprint-workspace/store'
+import type { SprintWorkspaceTaskDetail } from '@/stores/sprint-workspace/types'
+
+const TASK_DETAIL: SprintWorkspaceTaskDetail = {
+  id: 't1',
+  code: 'T-1',
+  title: 'Mijn taak',
+  description: 'Beschrijving',
+  priority: 2,
+  sort_order: 1,
+  status: 'in_progress',
+  story_id: 'story-1',
+  sprint_id: 'sprint-1',
+  created_at: new Date('2026-01-15'),
+  _detail: true,
+  implementation_plan: 'Stap 1\nStap 2',
+}
+
+function resetStore() {
+  useSprintWorkspaceStore.setState((s) => {
+    s.context.activeProduct = null
+    s.context.activeSprintId = null
+    s.context.activeStoryId = null
+    s.context.activeTaskId = null
+    s.entities.sprintsById = {}
+    s.entities.storiesById = {}
+    s.entities.tasksById = {}
+    s.relations.sprintIdsByProduct = {}
+    s.relations.storyIdsBySprint = {}
+    s.relations.taskIdsByStory = {}
+    s.loading.loadedProductSprintsIds = {}
+    s.loading.loadingProductId = null
+    s.loading.loadedSprintIds = {}
+    s.loading.loadingSprintId = null
+    s.loading.loadedStoryIds = {}
+    s.loading.loadedTaskIds = {}
+    s.loading.activeRequestId = null
+    s.pendingMutations = {}
+  })
+}
+
+beforeEach(() => {
+  resetStore()
+})
+
+afterEach(() => {
+  vi.restoreAllMocks()
+})
+
+describe('SprintTaskDialogMount', () => {
+  it('rendert niets wanneer er geen active task is', () => {
+    const { container } = render(
+      <SprintTaskDialogMount productId="p1" isDemo={false} />,
+    )
+    expect(container.textContent).toBe('')
+  })
+
+  it('rendert niets wanneer active task geen _detail heeft', () => {
+    useSprintWorkspaceStore.setState((s) => {
+      s.entities.tasksById['t1'] = {
+        id: 't1',
+        code: 'T-1',
+        title: 'Mijn taak',
+        description: null,
+        priority: 2,
+        sort_order: 1,
+        status: 'todo',
+        story_id: 'story-1',
+        sprint_id: 'sprint-1',
+        created_at: new Date(),
+      }
+      s.context.activeTaskId = 't1'
+    })
+
+    const { container } = render(
+      <SprintTaskDialogMount productId="p1" isDemo={false} />,
+    )
+    expect(container.textContent).toBe('')
+  })
+
+  it('rendert TaskDialog met titel "Taak bewerken" wanneer detail aanwezig is', () => {
+    useSprintWorkspaceStore.setState((s) => {
+      s.entities.tasksById['t1'] = TASK_DETAIL
+      s.context.activeTaskId = 't1'
+    })
+
+    render(<SprintTaskDialogMount productId="p1" isDemo={false} />)
+
+    expect(screen.getByText('Taak bewerken')).toBeTruthy()
+    expect((screen.getByLabelText(/Titel/) as HTMLInputElement).value).toBe('Mijn taak')
+  })
+
+  it('clear activeTaskId wanneer Annuleren wordt geklikt', async () => {
+    useSprintWorkspaceStore.setState((s) => {
+      s.entities.tasksById['t1'] = TASK_DETAIL
+      s.context.activeTaskId = 't1'
+    })
+
+    render(<SprintTaskDialogMount productId="p1" isDemo={false} />)
+
+    fireEvent.click(screen.getByRole('button', { name: 'Annuleren' }))
+
+    await waitFor(() => {
+      expect(useSprintWorkspaceStore.getState().context.activeTaskId).toBeNull()
+    })
+  })
+})
diff --git a/app/(app)/products/[id]/sprint/[sprintId]/page.tsx b/app/(app)/products/[id]/sprint/[sprintId]/page.tsx
index 84ec08e..4306219 100644
--- a/app/(app)/products/[id]/sprint/[sprintId]/page.tsx
+++ b/app/(app)/products/[id]/sprint/[sprintId]/page.tsx
@@ -1,4 +1,3 @@
-import { Suspense } from 'react'
 import { notFound, redirect } from 'next/navigation'
 import { getSession } from '@/lib/auth'
 import { getAccessibleProduct } from '@/lib/product-access'
@@ -9,6 +8,8 @@ import {
   SprintHydrationWrapper,
   type SprintHydrationData,
 } from '@/components/sprint/sprint-hydration-wrapper'
+import { SprintTaskDialogMount } from '@/components/sprint/sprint-task-dialog-mount'
+import { SprintUrlTaskSync } from '@/components/sprint/sprint-url-task-sync'
 import { SyncActiveSprintCookie } from '@/components/sprint/sync-active-sprint-cookie'
 import { SprintSwitcher } from '@/components/shared/sprint-switcher'
 import { getSprintSwitcherData } from '@/lib/sprint-switcher-data'
@@ -18,8 +19,6 @@ import { parsePauseContext } from '@/lib/pause-context'
 import type { SprintStory, PbiWithStories, ProductMember } from '@/components/sprint/sprint-backlog'
 import type { SprintWorkspaceTask } from '@/stores/sprint-workspace/types'
 import { TaskDialog } from '@/app/_components/tasks/task-dialog'
-import { EditTaskLoader } from '@/app/_components/tasks/edit-task-loader'
-import { TaskDialogSkeleton } from '@/app/_components/tasks/task-dialog-skeleton'
 import Link from 'next/link'
 
 interface Props {
@@ -27,13 +26,12 @@ interface Props {
   searchParams: Promise<{
     newTask?: string
     storyId?: string
-    editTask?: string
   }>
 }
 
 export default async function SprintBoardPage({ params, searchParams }: Props) {
   const { id, sprintId } = await params
-  const { newTask, storyId: storyIdParam, editTask } = await searchParams
+  const { newTask, storyId: storyIdParam } = await searchParams
 
   const session = await getSession()
   if (!session.userId) redirect('/login')
@@ -229,6 +227,8 @@ export default async function SprintBoardPage({ params, searchParams }: Props) {
             currentUserId={session.userId}
             members={members}
           />
+          <SprintTaskDialogMount productId={id} isDemo={isDemo} />
+          <SprintUrlTaskSync />
         </SprintHydrationWrapper>
       </div>
 
@@ -246,18 +246,6 @@ export default async function SprintBoardPage({ params, searchParams }: Props) {
           isDemo={isDemo}
         />
       )}
-
-      {editTask && !newTask && (
-        <Suspense fallback={<TaskDialogSkeleton />}>
-          <EditTaskLoader
-            taskId={editTask}
-            userId={session.userId}
-            productId={id}
-            closePath={closePath}
-            isDemo={isDemo}
-          />
-        </Suspense>
-      )}
     </div>
   )
 }
diff --git a/app/_components/tasks/task-dialog.tsx b/app/_components/tasks/task-dialog.tsx
index 3431cda..638d834 100644
--- a/app/_components/tasks/task-dialog.tsx
+++ b/app/_components/tasks/task-dialog.tsx
@@ -60,7 +60,9 @@ interface TaskDialogProps {
   task?: TaskDialogTask
   storyId?: string
   productId: string
-  closePath: string
+  closePath?: string
+  onClose?: () => void
+  onSaved?: (taskId: string) => void
   isDemo?: boolean
 }
 
@@ -81,7 +83,7 @@ const textareaClass = cn(
   'overflow-y-auto',
 )
 
-export function TaskDialog({ task, storyId, productId, closePath, isDemo = false }: TaskDialogProps) {
+export function TaskDialog({ task, storyId, productId, closePath, onClose, onSaved, isDemo = false }: TaskDialogProps) {
   const router = useRouter()
   const [isPending, startTransition] = useTransition()
   const [confirmDelete, setConfirmDelete] = useState(false)
@@ -100,11 +102,12 @@ export function TaskDialog({ task, storyId, productId, closePath, isDemo = false
     },
   })
 
-  function handleClose() {
-    router.push(closePath)
+  function close() {
+    if (onClose) { onClose(); return }
+    if (closePath) router.push(closePath)
   }
 
-  const closeGuard = useDirtyCloseGuard(form.formState.isDirty, handleClose)
+  const closeGuard = useDirtyCloseGuard(form.formState.isDirty, close)
   const handleKeyDown = useDialogSubmitShortcut(() => form.handleSubmit(onSubmit)())
 
   function onSubmit(data: TaskInput) {
@@ -117,7 +120,8 @@ export function TaskDialog({ task, storyId, productId, closePath, isDemo = false
 
       if (result.ok) {
         toast.success(isEdit ? 'Taak opgeslagen' : 'Taak aangemaakt')
-        router.push(closePath)
+        onSaved?.(result.task.id)
+        close()
         return
       }
 
@@ -152,7 +156,7 @@ export function TaskDialog({ task, storyId, productId, closePath, isDemo = false
       const result = await deleteTask(task.id, { productId })
       if (result.ok) {
         toast.success('Taak verwijderd')
-        router.push(closePath)
+        close()
         return
       }
       if (result.code === 403) {
diff --git a/components/sprint/sprint-task-dialog-mount.tsx b/components/sprint/sprint-task-dialog-mount.tsx
new file mode 100644
index 0000000..1ca0f45
--- /dev/null
+++ b/components/sprint/sprint-task-dialog-mount.tsx
@@ -0,0 +1,41 @@
+'use client'
+
+import { useSprintWorkspaceStore } from '@/stores/sprint-workspace/store'
+import { selectActiveTask } from '@/stores/sprint-workspace/selectors'
+import { isDetail } from '@/stores/sprint-workspace/types'
+import { TaskDialog } from '@/app/_components/tasks/task-dialog'
+import { taskStatusFromApi } from '@/lib/task-status'
+import type { TaskStatus } from '@prisma/client'
+
+interface Props {
+  productId: string
+  isDemo: boolean
+}
+
+export function SprintTaskDialogMount({ productId, isDemo }: Props) {
+  const task = useSprintWorkspaceStore(selectActiveTask)
+  const setActiveTask = useSprintWorkspaceStore((s) => s.setActiveTask)
+
+  if (!task || !isDetail(task)) return null
+
+  const status = (taskStatusFromApi(String(task.status)) ?? 'TO_DO') as TaskStatus
+  const createdAt = task.created_at instanceof Date ? task.created_at : new Date(task.created_at)
+
+  return (
+    <TaskDialog
+      task={{
+        id: task.id,
+        code: task.code,
+        title: task.title,
+        description: task.description,
+        implementation_plan: task.implementation_plan ?? null,
+        priority: task.priority,
+        status,
+        created_at: createdAt,
+      }}
+      productId={productId}
+      onClose={() => setActiveTask(null)}
+      isDemo={isDemo}
+    />
+  )
+}
diff --git a/components/sprint/sprint-url-task-sync.tsx b/components/sprint/sprint-url-task-sync.tsx
new file mode 100644
index 0000000..893b0af
--- /dev/null
+++ b/components/sprint/sprint-url-task-sync.tsx
@@ -0,0 +1,29 @@
+'use client'
+
+// PBI-75: URL-deeplink → store sync voor sprint task-edit.
+//
+// Patroon spiegelt components/backlog/url-task-sync.tsx: zodra de route
+// `?editTask=<id>` draagt, schrijven we de taak-hint en roepen we
+// setActiveTask aan op de sprint-workspace-store. De dialog wordt
+// vervolgens client-side gemount door SprintTaskDialogMount.
+
+import { useEffect } from 'react'
+import { useSearchParams } from 'next/navigation'
+import { useSprintWorkspaceStore } from '@/stores/sprint-workspace/store'
+import { writeTaskHint } from '@/stores/sprint-workspace/restore'
+
+export function SprintUrlTaskSync() {
+  const searchParams = useSearchParams()
+  const editTask = searchParams.get('editTask')
+
+  useEffect(() => {
+    if (!editTask) return
+    const sprintId = useSprintWorkspaceStore.getState().context.activeSprintId
+    if (sprintId) {
+      writeTaskHint(sprintId, editTask)
+    }
+    useSprintWorkspaceStore.getState().setActiveTask(editTask)
+  }, [editTask])
+
+  return null
+}
diff --git a/components/sprint/task-list.tsx b/components/sprint/task-list.tsx
index d95ed60..c4ea4a3 100644
--- a/components/sprint/task-list.tsx
+++ b/components/sprint/task-list.tsx
@@ -223,7 +223,7 @@ export function TaskList({ sprintId: _sprintId, productId: _productId, isDemo }:
   }
 
   function openEditDialog(taskId: string) {
-    router.push(`${pathname}?editTask=${taskId}`)
+    useSprintWorkspaceStore.getState().setActiveTask(taskId)
   }
 
   return (
diff --git a/docs/INDEX.md b/docs/INDEX.md
index 3848845..ef5e696 100644
--- a/docs/INDEX.md
+++ b/docs/INDEX.md
@@ -53,6 +53,7 @@ Auto-generated on 2026-05-10 from front-matter and headings.
 | [M12 — Idea entity + Grill/Plan Claude jobs](./plans/M12-ideas.md) | planned | — |
 | [M9 — Actief Product Backlog](./plans/M9-active-product-backlog.md) | active | 2026-05-03 |
 | [PBI-11 — Mobile-shell met landscape-lock (settings + backlog + solo)](./plans/PBI-11-mobile-shell.md) | — | — |
+| [PBI-75 — Sprint task-edit client-side via workspace-store](./plans/PBI-75-sprint-task-edit-store.md) | — | — |
 | [Queue-loop verplaatsen van Claude naar runner](./plans/queue-loop-extraction.md) | — | — |
 | [Advies - SprintRun, PR en worktree lifecycle als state machines](./plans/sprint-pr-worktree-state-machines.md) | draft | 2026-05-06 |
 | [ST-1109 — PBI krijgt een status (Ready / Blocked / Done)](./plans/ST-1109-pbi-status.md) | active | 2026-05-03 |
diff --git a/docs/plans/PBI-75-sprint-task-edit-store.md b/docs/plans/PBI-75-sprint-task-edit-store.md
new file mode 100644
index 0000000..b122553
--- /dev/null
+++ b/docs/plans/PBI-75-sprint-task-edit-store.md
@@ -0,0 +1,128 @@
+# PBI-75 — Sprint task-edit client-side via workspace-store
+
+## Context
+
+In het Sprint-scherm (`/products/<id>/sprint/<sprintId>`) duurt het bewerken van een taak onevenredig lang. Klik op een taakregel of het potlood-icoon roept `router.push(?editTask=<id>)` aan vanuit [`components/sprint/task-list.tsx:226`](../../components/sprint/task-list.tsx). Dat triggert:
+
+- **Volledige server re-render** van [`app/(app)/products/[id]/sprint/[sprintId]/page.tsx`](../../app/(app)/products/[id]/sprint/[sprintId]/page.tsx) met zware queries (sprint, alle sprintStories+tasks, productMembers, alle PBIs+stories voor het backlog-paneel)
+- **Tweede Prisma-query** in [`EditTaskLoader`](../../app/_components/tasks/edit-task-loader.tsx) voor task-detail (incl. `implementation_plan`)
+- **Na save**: `router.push(closePath)` + `revalidatePath` → opnieuw alle queries
+
+De [`sprint-workspace-store`](../../stores/sprint-workspace/store.ts) (sinds PBI-74 Story 9) bevat al alles voor een client-side edit-flow:
+
+- [`setActiveTask(taskId)`](../../stores/sprint-workspace/store.ts) (regel 337) — zet `context.activeTaskId` + roept `ensureTaskLoaded()` aan
+- [`ensureTaskLoaded(taskId)`](../../stores/sprint-workspace/store.ts) (regel 414) — `GET /api/tasks/{id}` → upsert met `_detail: true`
+- [`selectActiveTask`](../../stores/sprint-workspace/selectors.ts) (regel 91) — bestaat, nog geen consumer
+- [`applyTaskEvent`](../../stores/sprint-workspace/store.ts) (regel 748) — SSE-events propageren idempotent na server-save
+- Optimistic-mutation primitives (`applyOptimisticMutation` / `settleMutation` / `rollbackMutation`)
+
+Het patroon "URL-param → store" bestaat al voor product-workspace in [`components/backlog/url-task-sync.tsx`](../../components/backlog/url-task-sync.tsx) — we volgen dat als precedent.
+
+**Doel**: klik op een taak opent de edit-dialoog client-side via store-state binnen ~100ms. Geen URL-navigatie, geen server re-render, alleen `GET /api/tasks/{id}` voor het detail.
+
+## Aanpak
+
+**Architectuur**: store-mounted dialog + URL-sync component voor deeplinks.
+
+1. **Klik-flow**: `TaskList.openEditDialog` roept `setActiveTask(taskId)` aan op de store. Geen `router.push`.
+2. **Render-flow**: nieuwe client-component `SprintTaskDialogMount` zit binnen `SprintHydrationWrapper`, subscribet `selectActiveTask`, en rendert `<TaskDialog>` zodra de active task `_detail === true` is.
+3. **Save-flow**: `TaskDialog` krijgt optionele `onClose`/`onSaved` callbacks (backwards compatible met bestaande `closePath`). Mount geeft `onClose = () => setActiveTask(null)`. Server action `saveTask` blijft `revalidatePath` doen voor server-cache; SSE-event update store via `applyTaskEvent`.
+4. **Deeplink-flow**: nieuwe `SprintUrlTaskSync` leest `?editTask=<id>` en roept `setActiveTask(id)` aan (analoog aan `url-task-sync.tsx`).
+
+## Bestanden + wijzigingen
+
+### Nieuw — `components/sprint/sprint-task-dialog-mount.tsx`
+Client component. Subscribet `selectActiveTask` (single-value, geen `useShallow`). Wanneer task aanwezig is en `isDetail(task)` true, mappt naar `TaskDialogTask`-shape:
+- `status`: via `taskStatusFromApi` uit [`lib/task-status.ts`](../../lib/task-status.ts) (lowercase API → Prisma UPPER_SNAKE)
+- `implementation_plan: task.implementation_plan ?? null`
+- `created_at: new Date(task.created_at)`
+
+Rendert `<TaskDialog task={mapped} productId={productId} onClose={() => setActiveTask(null)} isDemo={isDemo} />`. Geen render tussen `setActiveTask` en `_detail: true` (detail-fetch <100ms).
+
+### Nieuw — `components/sprint/sprint-url-task-sync.tsx`
+Kopie van [`components/backlog/url-task-sync.tsx`](../../components/backlog/url-task-sync.tsx) maar tegen `useSprintWorkspaceStore` en `writeTaskHint` uit [`stores/sprint-workspace/restore`](../../stores/sprint-workspace/restore.ts).
+
+### Wijziging — `components/sprint/task-list.tsx` (regels 225-227)
+Vervang:
+```ts
+function openEditDialog(taskId: string) {
+  router.push(`${pathname}?editTask=${taskId}`)
+}
+```
+door:
+```ts
+function openEditDialog(taskId: string) {
+  useSprintWorkspaceStore.getState().setActiveTask(taskId)
+}
+```
+`openCreateDialog` (regel 222) blijft URL-gebaseerd — out-of-scope.
+
+### Wijziging — `app/(app)/products/[id]/sprint/[sprintId]/page.tsx`
+- Verwijder `editTask` uit searchParams-destructuring (regel 36)
+- Verwijder `editTask &&`-block met `<Suspense><EditTaskLoader>` (regels 250-260)
+- Verwijder ongebruikte imports (`EditTaskLoader`, `TaskDialogSkeleton`, evt. `Suspense`)
+- Mount binnen `SprintHydrationWrapper`:
+  ```tsx
+  <SprintHydrationWrapper ...>
+    <SprintBoardClient ... />
+    <SprintTaskDialogMount productId={id} isDemo={isDemo} />
+    <SprintUrlTaskSync />
+  </SprintHydrationWrapper>
+  ```
+- `newTask`-block (regels 241-248) blijft ongemoeid — out-of-scope.
+
+### Wijziging — `app/_components/tasks/task-dialog.tsx`
+Maak `closePath` optioneel + voeg `onClose`/`onSaved` toe (backwards compatible):
+```ts
+interface TaskDialogProps {
+  task?: TaskDialogTask
+  storyId?: string
+  productId: string
+  closePath?: string
+  onClose?: () => void
+  onSaved?: (taskId: string) => void
+  isDemo?: boolean
+}
+```
+Refactor de drie `router.push(closePath)`-calls (regels 104, 120, 155) naar één helper:
+```ts
+function close() {
+  if (onClose) { onClose(); return }
+  if (closePath) router.push(closePath)
+}
+```
+Bestaande callers (`EditTaskLoader`, mobile, product-page, sprint `newTask`-block) blijven werken via `closePath`. Nieuwe `SprintTaskDialogMount` gebruikt `onClose`.
+
+### Geen wijziging
+- `stores/sprint-workspace/selectors.ts` — `selectActiveTask` bestaat al
+- `app/_components/tasks/edit-task-loader.tsx` — nog gebruikt door product-page en mobile
+
+## Edge cases
+
+- **Status-enum mapping**: store API-lowercase → Prisma UPPER_SNAKE via `taskStatusFromApi`, fallback `'TO_DO'`
+- **`_detail: true` race**: mount rendert pas wanneer `isDetail(task)` true is — geen flash met undefined velden
+- **Demo-mode**: prop blijft via server doorlopen, dialog respecteert al `isDemo`
+- **Dirty-close-guard**: ingebouwd in dialog (regels 107, 172) — werkt via `onClose`
+- **SSE na save**: `applyTaskEvent` updatet store automatisch
+- **Deeplink + task niet bestaat**: `GET /api/tasks/{id}` 404 → store doet niets, dialog opent niet (huidige `redirect()` verdwijnt — acceptabel)
+
+## Verificatie
+
+1. **Browser** (`npm run dev`): klik op task in takenlijst → dialog opent <100ms, geen URL-verandering, alleen `GET /api/tasks/<id>` in Network
+2. **Save**: wijzig titel → Opslaan → dialog sluit → store toont nieuwe titel via SSE
+3. **Deeplink**: `?editTask=<id>` → dialog opent via `SprintUrlTaskSync`
+4. **Bestaande flows ongebroken**: product-page edit, mobile edit, sprint `?newTask=1`
+5. **`npm run verify && npm run build`**
+6. **Vitest**: `__tests__/components/sprint/sprint-task-dialog-mount.test.tsx` — hydreer store, mock fetch, `setActiveTask(id)`, assert UPPER_SNAKE status + `onClose` clear
+
+## Risico's
+
+- Andere mounts (mobile, product-backlog, sprint `newTask`) blijven URL-gebaseerd — `closePath?` optional houdt ze werkend
+- Geen `redirect()` bij not-found-deeplink (klein UX-verschil)
+- SSE-latency 100-500ms na save — eventueel later mitigeren via `applyOptimisticMutation` in `onSaved`-callback
+
+## Out-of-scope (follow-up PBIs)
+
+- `?newTask=1`-flow naar store
+- Mobile + product-backlog mounts
+- `EditTaskLoader` verwijderen wanneer alle callers over zijn