feat(desktop): define workspace-scoped pane ownership

apps/desktop/src/app/chat/pane-mirror.test.ts

@@ -0,0 +1,80 @@
+import { atom } from 'nanostores'
+import { afterEach, describe, expect, it } from 'vitest'
+
+import { registry } from '@/contrib/registry'
+
+import { paneMirror } from './pane-mirror'
+
+interface Tile {
+  id: string
+  owner?: string
+}
+
+const cleanupSources: Array<ReturnType<typeof atom<Tile[]>>> = []
+let sequence = 0
+
+function setup(options: {
+  workspaceMode?: 'sessions' | 'bots' | ((tile: Tile) => 'sessions' | 'bots' | undefined)
+  workspaceOwnerKey?: string | ((tile: Tile) => string | undefined)
+}) {
+  const source = atom<Tile[]>([])
+  const prefix = `pane-mirror-scope-${sequence++}`
+  cleanupSources.push(source)
+
+  paneMirror<Tile>({
+    source,
+    key: tile => tile.id,
+    prefix,
+    minWidth: '10rem',
+    title: key => key,
+    render: () => null,
+    close: () => undefined,
+    ...options
+  })()
+
+  return {
+    source,
+    contribution: (id: string) => registry.getArea('panes').find(entry => entry.id === `${prefix}:${id}`)
+  }
+}
+
+afterEach(() => {
+  for (const source of cleanupSources.splice(0)) {
+    source.set([])
+  }
+})
+
+describe('paneMirror workspace scope', () => {
+  it('forwards a static workspace mode', () => {
+    const mirror = setup({ workspaceMode: 'sessions' })
+    mirror.source.set([{ id: 'one' }])
+
+    expect(mirror.contribution('one')).toMatchObject({
+      workspaceMode: 'sessions',
+      workspaceOwnerKey: undefined
+    })
+  })
+
+  it('resolves owner callbacks per tile and refreshes an unchanged title', () => {
+    const mirror = setup({
+      workspaceMode: 'bots',
+      workspaceOwnerKey: tile => tile.owner
+    })
+
+    mirror.source.set([{ id: 'one', owner: 'connection-a::default' }])
+    expect(mirror.contribution('one')?.workspaceOwnerKey).toBe('connection-a::default')
+
+    mirror.source.set([{ id: 'one', owner: 'connection-b::default' }])
+    expect(mirror.contribution('one')?.workspaceOwnerKey).toBe('connection-b::default')
+  })
+
+  it('leaves existing callers unscoped when options are omitted', () => {
+    const mirror = setup({})
+    mirror.source.set([{ id: 'one' }])
+
+    expect(mirror.contribution('one')).toMatchObject({
+      workspaceMode: undefined,
+      workspaceOwnerKey: undefined
+    })
+  })
+})

apps/desktop/src/app/chat/pane-mirror.ts

@@ -11,13 +11,23 @@ import type { ReactElement, ReactNode, PointerEvent as ReactPointerEvent } from
 
 import { registerPaneCloser, removeTreePane, treePanesWithPrefix } from '@/components/pane-shell/tree/store'
 import { registry } from '@/contrib/registry'
+import type { WorkspaceMode } from '@/contrib/types'
 import type { TileDock } from '@/store/session-states'
 
+type WorkspaceValue<T, V> = V | ((tile: T) => V | undefined)
+
+const workspaceValue = <T, V>(value: WorkspaceValue<T, V> | undefined, tile: T): V | undefined =>
+  typeof value === 'function' ? (value as (tile: T) => V | undefined)(tile) : value
+
 export interface PaneMirror<T> {
   /** Reactive source list. */
   source: ReadableAtom<T[]>
   /** Extra atoms whose changes should re-sync (e.g. titles living elsewhere). */
   also?: ReadableAtom<unknown>[]
+  /** Workspace surface this tile belongs to. Omit for a global pane. */
+  workspaceMode?: WorkspaceValue<T, WorkspaceMode>
+  /** Exact opaque owner inside Bot Mode. Omit outside an owner-scoped pane. */
+  workspaceOwnerKey?: WorkspaceValue<T, string>
   /** Stable key + pane-id seed for a tile. */
   key: (tile: T) => string
   /** Pane-id namespace — the id is `${prefix}:${key}`. */
@@ -51,7 +61,11 @@ export interface PaneMirror<T> {
 /** Build a `watch*` fn: syncs once, then re-syncs on every source/also change.
  *  Module-level state lives in the returned closure, so call it once per app. */
 export function paneMirror<T>(cfg: PaneMirror<T>): () => void {
-  const registered = new Map<string, { dispose: () => void; title: string }>()
+  const registered = new Map<
+    string,
+    { dispose: () => void; title: string; workspaceMode?: WorkspaceMode; workspaceOwnerKey?: string }
+  >()
+
   const paneId = (key: string) => `${cfg.prefix}:${key}`
 
   const sync = () => {
@@ -61,10 +75,17 @@ export function paneMirror<T>(cfg: PaneMirror<T>): () => void {
     for (const tile of tiles) {
       const key = cfg.key(tile)
       const title = cfg.title(key)
+      const workspaceMode = workspaceValue(cfg.workspaceMode, tile)
+      const workspaceOwnerKey = workspaceValue(cfg.workspaceOwnerKey, tile)
       const current = registered.get(key)
 
       // register() replaces same-id in place — safe for live title refreshes.
-      if (current && current.title === title) {
+      if (
+        current &&
+        current.title === title &&
+        current.workspaceMode === workspaceMode &&
+        current.workspaceOwnerKey === workspaceOwnerKey
+      ) {
         continue
       }
 
@@ -90,10 +111,12 @@ export function paneMirror<T>(cfg: PaneMirror<T>): () => void {
             : undefined, // returns boolean (handled) — see PaneChrome.tabDrag
           tabWrap: cfg.tabWrap ? (tab: ReactElement) => cfg.tabWrap!(key, tab) : undefined
         },
-        render: () => cfg.render(key)
+        render: () => cfg.render(key),
+        workspaceMode,
+        workspaceOwnerKey
       })
 
-      registered.set(key, { dispose, title })
+      registered.set(key, { dispose, title, workspaceMode, workspaceOwnerKey })
 
       if (!current) {
         registerPaneCloser(paneId(key), () => cfg.close(key))

apps/desktop/src/app/chat/preview-tile.tsx

@@ -122,6 +122,7 @@ export function watchPreviewTiles(): void {
 
 const watchPreviewTileMirror = paneMirror<{ id: string }>({
   source: $previewTabs,
+  workspaceMode: 'sessions',
   key: tab => tab.id,
   prefix: PREVIEW_TILE_PREFIX,
   // Identical to route (page) tiles: its own zone docked beside main, sized by

apps/desktop/src/app/chat/route-tile.tsx

@@ -86,6 +86,7 @@ function RouteTilePane({ path }: { path: string }) {
 /** Keep pane contributions mirroring `$routeTiles`. Call once from the root. */
 export const watchRouteTiles = paneMirror<RouteTile>({
   source: $routeTiles,
+  workspaceMode: 'sessions',
   key: t => t.path,
   prefix: 'route-tile',
   dir: t => t.dir,

apps/desktop/src/app/chat/session-tile.tsx

@@ -595,6 +595,8 @@ export function WorkspaceTabMenu({ children }: { children: React.ReactElement })
  *  `$sessions`). Tiles dock against main on the chosen edge, flex width. */
 export const watchSessionTiles = paneMirror<SessionTile>({
   source: $sessionTiles,
+  workspaceMode: tile => tile.workspaceMode ?? 'sessions',
+  workspaceOwnerKey: tile => tile.workspaceOwnerKey,
   // $projectTree: a tile whose session is older than the recents page resolves
   // its title through the tree, which loads after the tiles register. (The tab's
   // status dot subscribes to color/state itself, so it needs no `also` entry.)

apps/desktop/src/app/contrib/controller.tsx

@@ -176,6 +176,7 @@ registry.registerMany([
   {
     id: 'workspace',
     area: 'panes',
+    workspaceMode: 'sessions',
     // Live-retitled to the loaded session by syncWorkspaceTitle below.
     title: NEW_SESSION_TITLE,
     data: {
@@ -482,6 +483,7 @@ const syncWorkspaceTitle = () => {
   registry.register({
     id: 'workspace',
     area: 'panes',
+    workspaceMode: 'sessions',
     // The placeholder, not the draft's live name — `tabTitle` below renders
     // that. Keeping it here would re-register the pane on every keystroke.
     title: stored ? storedSessionTitle(stored) : NEW_SESSION_TITLE,

apps/desktop/src/app/open-session.test.ts

@@ -3,6 +3,7 @@ import { beforeEach, describe, expect, it, vi } from 'vitest'
 const focusOpenSession = vi.fn()
 const openSessionTile = vi.fn()
 const reuseBlankDraftTile = vi.fn()
+const setSessionTileWorkspaceScope = vi.fn()
 const openSessionInNewWindow = vi.fn()
 const canOpenSessionWindow = vi.fn(() => true)
 const workspaceIsPageGet = vi.fn(() => false)
@@ -12,7 +13,8 @@ vi.mock('@/store/session-states', () => ({
     !focused || (focused === 'main' && workspaceIsPage),
   focusOpenSession: (...args: unknown[]) => focusOpenSession(...args),
   openSessionTile: (...args: unknown[]) => openSessionTile(...args),
-  reuseBlankDraftTile: (...args: unknown[]) => reuseBlankDraftTile(...args)
+  reuseBlankDraftTile: (...args: unknown[]) => reuseBlankDraftTile(...args),
+  setSessionTileWorkspaceScope: (...args: unknown[]) => setSessionTileWorkspaceScope(...args)
 }))
 
 vi.mock('@/store/windows', () => ({
@@ -89,6 +91,7 @@ describe('openSession', () => {
     canOpenSessionWindow.mockReturnValue(true)
     workspaceIsPageGet.mockReturnValue(false)
     reuseBlankDraftTile.mockReset()
+    setSessionTileWorkspaceScope.mockReset()
     $activeSessionId.set(null)
     $selectedStoredSessionId.set(null)
   })
@@ -143,6 +146,16 @@ describe('openSession', () => {
     expect(navigate).not.toHaveBeenCalled()
   })
 
+  it('threads an exact Bot owner into a new session tile', () => {
+    const scope = { workspaceMode: 'bots' as const, workspaceOwnerKey: 'connection-a::default' }
+    focusOpenSession.mockReturnValue(null)
+
+    openSession('s1', navigate, 'tab', scope)
+
+    expect(setSessionTileWorkspaceScope).toHaveBeenCalledWith('s1', scope)
+    expect(openSessionTile).toHaveBeenCalledWith('s1', 'center', undefined, undefined, scope)
+  })
+
   it('stack focuses a session that is already on screen', () => {
     $selectedStoredSessionId.set('s0')
     focusOpenSession.mockReturnValue('tile')

apps/desktop/src/app/open-session.ts

@@ -14,12 +14,14 @@
  *   - `window` (⇧⌘-click) — pop into its own window; falls back to `tab` when
  *     the bridge has no session-window support.
  */
+import type { WorkspaceMode } from '@/contrib/types'
 import { $activeSessionId, $selectedStoredSessionId, markSessionRead } from '@/store/session'
 import {
   focusedSessionNeedsRoute,
   focusOpenSession,
   openSessionTile,
-  reuseBlankDraftTile
+  reuseBlankDraftTile,
+  setSessionTileWorkspaceScope
 } from '@/store/session-states'
 import { canOpenSessionWindow, openSessionInNewWindow } from '@/store/windows'
 
@@ -29,6 +31,11 @@ export type OpenSessionIntent = 'in-place' | 'main' | 'stack' | 'tab' | 'window'
 
 export type OpenSessionNavigate = (to: string, options?: { replace?: boolean }) => void
 
+export interface OpenSessionWorkspaceScope {
+  workspaceMode: WorkspaceMode
+  workspaceOwnerKey?: string
+}
+
 /**
  * Is the main tab holding a conversation worth preserving?
  *
@@ -72,7 +79,8 @@ export function openSessionIntentFromModifiers(
 export function openSession(
   storedSessionId: string,
   navigate: OpenSessionNavigate,
-  intent: OpenSessionIntent = 'in-place'
+  intent: OpenSessionIntent = 'in-place',
+  workspaceScope: OpenSessionWorkspaceScope = { workspaceMode: 'sessions' }
 ): void {
   if (!storedSessionId) {
     return
@@ -83,6 +91,8 @@ export function openSession(
   // already on screen (open tile, or the main session) would otherwise return
   // at focusOpenSession and never clear its unread dot.
   markSessionRead(storedSessionId)
+  setSessionTileWorkspaceScope(storedSessionId, workspaceScope)
+  const botWorkspaceScope = workspaceScope.workspaceMode === 'bots' ? workspaceScope : undefined
 
   let resolved: OpenSessionIntent = intent
 
@@ -128,11 +138,20 @@ export function openSession(
     // Nothing to jump to, but an open tab may still be an empty "New session" —
     // that's the tab the user would have typed into, so spend it rather than
     // stacking a second blank one beside it.
-    if (spendBlankDraft && reuseBlankDraftTile(storedSessionId)) {
+    if (
+      spendBlankDraft &&
+      (botWorkspaceScope
+        ? reuseBlankDraftTile(storedSessionId, botWorkspaceScope)
+        : reuseBlankDraftTile(storedSessionId))
+    ) {
       return
     }
 
-    openSessionTile(storedSessionId, 'center')
+    if (botWorkspaceScope) {
+      openSessionTile(storedSessionId, 'center', undefined, undefined, botWorkspaceScope)
+    } else {
+      openSessionTile(storedSessionId, 'center')
+    }
 
     return
   }

apps/desktop/src/components/pane-shell/tree/renderer/tree-group.tsx

@@ -10,7 +10,7 @@
  */
 
 import { useStore } from '@nanostores/react'
-import { type CSSProperties, Fragment, type ReactNode, type RefObject, useRef, useState } from 'react'
+import { type CSSProperties, Fragment, type ReactNode, type RefObject, useEffect, useRef, useState } from 'react'
 
 import { ActionsContextMenu, type MenuKit, renderActionItem } from '@/components/ui/actions-menu'
 import { Codicon } from '@/components/ui/codicon'
@@ -35,6 +35,14 @@ import { $layoutEditMode } from '../../edit-mode'
 import { useWindowControlsOverlap } from '../../geometry'
 import { emptyPaneLifecycleState, reconcilePaneLifecycle } from '../../pane-lifecycle'
 import { hiddenPaneProps, PaneGroupContext, PaneLifecycleContext, PaneVisibleContext } from '../../pane-visibility'
+import {
+  $workspaceMode,
+  $workspaceOwnerKey,
+  contributesToWorkspace,
+  rememberActivePane,
+  resolveRememberedActivePane,
+  workspaceScopeKey
+} from '../../workspace-scope'
 import type { DropPosition, GroupNode } from '../model'
 import {
   $dropHint,
@@ -228,6 +236,8 @@ export function TreeGroup({
 
   const hiddenPanes = useStore($hiddenTreePanes)
   const narrow = useStore($narrowViewport)
+  const workspaceMode = useStore($workspaceMode)
+  const workspaceOwnerKey = useStore($workspaceOwnerKey)
   const newSessionTabAction = useStore($newSessionTabAction)
   const panesWithCloser = useStore($panesWithCloser)
   // Multi-tab selection (⌥/Ctrl-click, Shift-click) — null for every zone but
@@ -245,12 +255,26 @@ export function TreeGroup({
   // Edit mode forces toggle-hidden panes visible so they can be rearranged
   // (mirrors tree-split's paneGone) — restores itself on exit.
   const paneShown = (id: string) =>
-    Boolean(paneFor(id)) && (editMode || !hiddenPanes.has(id)) && !(narrow && paneChrome(paneFor(id)).collapsible)
+    Boolean(paneFor(id)) &&
+    contributesToWorkspace(paneFor(id), workspaceMode, workspaceOwnerKey) &&
+    (editMode || !hiddenPanes.has(id)) &&
+    !(narrow && paneChrome(paneFor(id)).collapsible)
 
   const shown = node.panes.filter(paneShown)
-  const activeId = shown.includes(node.active) ? node.active : (shown[0] ?? node.active)
+  const memoryKey = workspaceScopeKey(workspaceMode, workspaceOwnerKey)
+
+  const activeId = shown.includes(node.active)
+    ? node.active
+    : (resolveRememberedActivePane(memoryKey, shown) ?? shown[0] ?? '')
+
   const active = paneFor(activeId)
-  const isEmpty = node.panes.length === 0
+  const isEmpty = shown.length === 0
+
+  useEffect(() => {
+    if (activeId) {
+      rememberActivePane(memoryKey, activeId)
+    }
+  }, [activeId, memoryKey])
 
   // BOUNDED KEEP-ALIVE: the active pane is visible, a small per-zone LRU stays
   // hot-hidden, and older panes park (unmount). This preserves fast tab

apps/desktop/src/components/pane-shell/tree/renderer/tree-split.tsx

@@ -17,6 +17,7 @@ import { cn } from '@/lib/utils'
 import { $paneStates, type PaneStateSnapshot, setPaneHeightOverride, setPaneWidthOverride } from '@/store/panes'
 
 import { $layoutEditMode } from '../../edit-mode'
+import { $workspaceMode, $workspaceOwnerKey, contributesToWorkspace } from '../../workspace-scope'
 import type { LayoutNode, SplitNode } from '../model'
 import { allPaneIds } from '../model'
 import {
@@ -90,6 +91,8 @@ export function TreeSplit({ node, root, rootRow }: { node: SplitNode; root?: boo
   const panes = useContributions('panes')
   const hiddenPanes = useStore($hiddenTreePanes)
   const narrow = useStore($narrowViewport)
+  const workspaceMode = useStore($workspaceMode)
+  const workspaceOwnerKey = useStore($workspaceOwnerKey)
   // Scoped to THIS subtree's panes: a sash drag writes size overrides on every
   // pointermove, but only the splits whose subtree actually resized should
   // re-render — not every split in the tree.
@@ -124,7 +127,10 @@ export function TreeSplit({ node, root, rootRow }: { node: SplitNode; root?: boo
   // closed) visible so they're rearrangeable — only truly-absent (unregistered)
   // or narrow-collapsed panes stay gone. Restores itself on exit (render-only).
   const paneGone = (id: string) =>
-    !paneFor(id) || (!editMode && hiddenPanes.has(id)) || (narrow && Boolean(paneChrome(paneFor(id)).collapsible))
+    !paneFor(id) ||
+    !contributesToWorkspace(paneFor(id), workspaceMode, workspaceOwnerKey) ||
+    (!editMode && hiddenPanes.has(id)) ||
+    (narrow && Boolean(paneChrome(paneFor(id)).collapsible))
 
   const trackCtx: TrackContext = { paneFor, paneGone, overrides }
 

apps/desktop/src/components/pane-shell/tree/renderer/workspace-scope.test.tsx

@@ -0,0 +1,96 @@
+import { act, type ReactNode } from 'react'
+import { createRoot, type Root } from 'react-dom/client'
+import { afterEach, describe, expect, it, vi } from 'vitest'
+
+import { setWorkspaceScope } from '@/components/pane-shell/workspace-scope'
+import { registry } from '@/contrib/registry'
+
+import type { GroupNode } from '../model'
+
+import { TreeGroup } from './tree-group'
+
+let root: null | Root = null
+let container: HTMLDivElement | null = null
+const disposers: Array<() => void> = []
+
+function render(ui: ReactNode) {
+  if (!container) {
+    container = globalThis.document.createElement('div')
+    globalThis.document.body.append(container)
+    root = createRoot(container)
+  }
+
+  act(() => root!.render(ui))
+}
+
+function register(id: string, title: string, scope: { workspaceMode?: 'sessions' | 'bots'; workspaceOwnerKey?: string } = {}) {
+  disposers.push(
+    registry.register({
+      area: 'panes',
+      data: { placement: 'main' },
+      id,
+      render: () => <div>{title} content</div>,
+      title,
+      ...scope
+    })
+  )
+}
+
+const group = (active: string): GroupNode => ({
+  active,
+  id: 'workspace-scope-zone',
+  panes: ['session-a', 'bot-a', 'bot-b'],
+  tabStrip: 'always',
+  type: 'group'
+})
+
+const visibleTabs = () =>
+  [...globalThis.document.querySelectorAll<HTMLElement>('[data-tree-tab]')].map(tab => tab.dataset.treeTab)
+
+afterEach(() => {
+  if (root) {
+    act(() => root!.unmount())
+  }
+
+  container?.remove()
+  disposers.splice(0).forEach(dispose => dispose())
+  act(() => {
+    setWorkspaceScope('sessions')
+  })
+  root = null
+  container = null
+  vi.unstubAllGlobals()
+})
+
+describe('TreeGroup workspace scope', () => {
+  it('renders only the current workspace owner and restores owner activity', () => {
+    vi.stubGlobal('CSS', { escape: (value: string) => value })
+    register('session-a', 'Session A', { workspaceMode: 'sessions' })
+    register('bot-a', 'Bot A', { workspaceMode: 'bots', workspaceOwnerKey: 'connection-a::default' })
+    register('bot-b', 'Bot B', { workspaceMode: 'bots', workspaceOwnerKey: 'connection-b::default' })
+
+    render(<TreeGroup node={group('session-a')} parentAxis="column" />)
+    expect(visibleTabs()).toEqual(['session-a'])
+    expect(container?.textContent).toContain('Session A content')
+
+    act(() => setWorkspaceScope('bots', 'connection-a::default'))
+    render(<TreeGroup node={group('bot-a')} parentAxis="column" />)
+    expect(visibleTabs()).toEqual(['bot-a'])
+    expect(container?.textContent).toContain('Bot A content')
+
+    act(() => setWorkspaceScope('bots', 'connection-b::default'))
+    render(<TreeGroup node={group('bot-b')} parentAxis="column" />)
+    expect(visibleTabs()).toEqual(['bot-b'])
+    expect(container?.textContent).toContain('Bot B content')
+
+    act(() => setWorkspaceScope('bots', 'connection-a::default'))
+    render(<TreeGroup node={group('bot-b')} parentAxis="column" />)
+    expect(visibleTabs()).toEqual(['bot-a'])
+    expect(container?.textContent).toContain('Bot A content')
+
+    act(() => setWorkspaceScope('sessions'))
+    render(<TreeGroup node={group('bot-b')} parentAxis="column" />)
+    expect(visibleTabs()).toEqual(['session-a'])
+    expect(container?.textContent).toContain('Session A content')
+  })
+})

apps/desktop/src/components/pane-shell/workspace-scope.test.ts

@@ -0,0 +1,169 @@
+import { afterEach, beforeEach, describe, expect, it } from 'vitest'
+
+import {
+  $workspaceMode,
+  $workspaceOwnerKey,
+  contributesToWorkspace,
+  filterContributionsForWorkspace,
+  forgetActivePane,
+  forgetRememberedPane,
+  rememberActivePane,
+  resetRememberedActivePanes,
+  resolveRememberedActivePane,
+  setWorkspaceScope
+} from './workspace-scope'
+
+interface ScopedContribution {
+  id: string
+  workspaceMode?: 'sessions' | 'bots'
+  workspaceOwnerKey?: string
+}
+
+const contribution = (
+  id: string,
+  scope?: Pick<ScopedContribution, 'workspaceMode' | 'workspaceOwnerKey'>
+): ScopedContribution => ({ id, ...scope })
+
+const bot = (ownerKey: string, suffix: string) =>
+  contribution(`bot:${suffix}`, {
+    workspaceMode: 'bots',
+    workspaceOwnerKey: ownerKey
+  })
+
+afterEach(() => {
+  setWorkspaceScope('sessions')
+})
+
+describe('workspace scope', () => {
+  it('defaults to the un-switched sessions window state', () => {
+    expect($workspaceMode.get()).toBe('sessions')
+    expect($workspaceOwnerKey.get()).toBeNull()
+  })
+
+  it('publishes a coherent mode and owner in one batch', () => {
+    const snapshots: Array<['sessions' | 'bots', string | null]> = []
+    const capture = () => snapshots.push([$workspaceMode.get(), $workspaceOwnerKey.get()])
+    const unbindMode = $workspaceMode.listen(capture)
+    const unbindOwner = $workspaceOwnerKey.listen(capture)
+    snapshots.length = 0
+
+    expect(setWorkspaceScope('bots', 'connection-a::default')).toBe(true)
+    expect(snapshots.length).toBeGreaterThan(0)
+    expect(snapshots.every(snapshot => snapshot[0] === 'bots' && snapshot[1] === 'connection-a::default')).toBe(true)
+    expect(setWorkspaceScope('bots', 'connection-a::default')).toBe(false)
+
+    unbindMode()
+    unbindOwner()
+  })
+
+  it('keeps global contributions visible in both modes', () => {
+    expect(contributesToWorkspace(undefined, 'sessions', null)).toBe(true)
+    expect(contributesToWorkspace(undefined, 'bots', 'bot-a')).toBe(true)
+  })
+
+  it('separates sessions and bots contributions by mode', () => {
+    const sessionsOnly = contribution('sessions-pane', { workspaceMode: 'sessions' })
+    const botsOnly = bot('bot-a', 'pane')
+
+    expect(contributesToWorkspace(sessionsOnly, 'sessions')).toBe(true)
+    expect(contributesToWorkspace(sessionsOnly, 'bots', 'bot-a')).toBe(false)
+    expect(contributesToWorkspace(botsOnly, 'sessions')).toBe(false)
+    expect(contributesToWorkspace(botsOnly, 'bots', 'bot-a')).toBe(true)
+  })
+
+  it('requires an exact non-empty owner match for bots contributions', () => {
+    const scoped = bot('bot-a', 'pane')
+
+    expect(contributesToWorkspace(scoped, 'bots', 'bot-b')).toBe(false)
+    expect(contributesToWorkspace(scoped, 'bots', null)).toBe(false)
+    expect(contributesToWorkspace(scoped, 'bots', '')).toBe(false)
+    expect(contributesToWorkspace(scoped, 'bots', 'bot-a')).toBe(true)
+
+    // A bots-scoped contribution with an empty owner key never participates.
+    const noOwner = contribution('no-owner', { workspaceMode: 'bots' })
+    expect(contributesToWorkspace(noOwner, 'bots', 'bot-a')).toBe(false)
+  })
+
+  it('does not collide on shared profile suffixes across connection-qualified keys', () => {
+    // Same profile suffix, different connections — opaque exact strings only.
+    const localProfile = bot('local:main', 'main')
+    const remoteProfile = bot('ssh:server:main', 'main')
+
+    expect(contributesToWorkspace(localProfile, 'bots', 'ssh:server:main')).toBe(false)
+    expect(contributesToWorkspace(remoteProfile, 'bots', 'local:main')).toBe(false)
+    expect(contributesToWorkspace(localProfile, 'bots', 'local:main')).toBe(true)
+    expect(contributesToWorkspace(remoteProfile, 'bots', 'ssh:server:main')).toBe(true)
+  })
+})
+
+describe('filterContributionsForWorkspace', () => {
+  it('filters to the current mode and preserves input order', () => {
+    const contributions = [
+      bot('bot-a', 'zeta'),
+      contribution('global-1'),
+      contribution('sessions-only', { workspaceMode: 'sessions' }),
+      bot('bot-a', 'alpha')
+    ]
+
+    expect(filterContributionsForWorkspace(contributions, 'bots', 'bot-a').map(c => c.id)).toEqual([
+      'bot:zeta',
+      'global-1',
+      'bot:alpha'
+    ])
+    expect(
+      filterContributionsForWorkspace(contributions, 'sessions', null).map(c => c.id)
+    ).toEqual(['global-1', 'sessions-only'])
+  })
+
+  it('returns the original array reference on a no-op', () => {
+    const contributions: ScopedContribution[] = [contribution('a'), contribution('b')]
+
+    expect(filterContributionsForWorkspace(contributions, 'sessions', null)).toBe(contributions)
+    expect(filterContributionsForWorkspace(contributions, 'bots', 'anything').length).toBe(2)
+  })
+})
+
+describe('remembered active panes', () => {
+  beforeEach(() => resetRememberedActivePanes())
+
+  it('remembers and restores panes independently per owner key', () => {
+    rememberActivePane('conn-a:profile-x', 'pane-1')
+    rememberActivePane('conn-b:profile-y', 'pane-2')
+
+    expect(resolveRememberedActivePane('conn-a:profile-x', ['pane-1', 'pane-2'])).toBe('pane-1')
+    expect(resolveRememberedActivePane('conn-b:profile-y', ['pane-1', 'pane-2'])).toBe('pane-2')
+  })
+
+  it('does not collide on a shared profile suffix across owner keys', () => {
+    rememberActivePane('local:main', 'pane-local')
+
+    expect(resolveRememberedActivePane('ssh:server:main', [])).toBeNull()
+  })
+
+  it('falls back after the remembered pane is removed', () => {
+    rememberActivePane('bot-a', 'pane-gone')
+
+    expect(resolveRememberedActivePane('bot-a', ['first', 'second'])).toBe('first')
+    expect(resolveRememberedActivePane('bot-a', [])).toBeNull()
+  })
+
+  it('forgets a single owner without touching others', () => {
+    rememberActivePane('bot-a', 'pane-a')
+    rememberActivePane('bot-b', 'pane-b')
+
+    forgetActivePane('bot-a')
+
+    expect(resolveRememberedActivePane('bot-a', ['fallback-a', 'pane-a'])).toBe('fallback-a')
+    expect(resolveRememberedActivePane('bot-b', ['pane-a', 'pane-b'])).toBe('pane-b')
+  })
+
+  it('forgets a removed pane across every owner that remembered it', () => {
+    rememberActivePane('bot-a', 'pane-gone')
+    rememberActivePane('bot-b', 'pane-gone')
+
+    forgetRememberedPane('pane-gone')
+
+    expect(resolveRememberedActivePane('bot-a', ['fallback-a'])).toBe('fallback-a')
+    expect(resolveRememberedActivePane('bot-b', ['fallback-b'])).toBe('fallback-b')
+  })
+})

apps/desktop/src/components/pane-shell/workspace-scope.ts

@@ -0,0 +1,167 @@
+/**
+ * Workspace scoping for contributions.
+ *
+ * Pure presentation-ownership helpers: which workspace surface (sessions vs
+ * bots) a contribution belongs to, and — within the bots surface — which exact
+ * bot it belongs to. Owner keys are opaque exact strings supplied by callers;
+ * this module never parses profile names or infers connections.
+ *
+ * No persistence here by design: the remembered active-pane map is window-local
+ * memory so a switch away and back can restore where the user was, without any
+ * of it surviving the window.
+ */
+
+import { atom, batch } from 'nanostores'
+
+import type { WorkspaceMode } from '../../contrib/types'
+
+/** Re-exported so workspace consumers can import it from here. */
+export type { WorkspaceMode } from '../../contrib/types'
+
+/** Default workspace mode when the host has not switched surfaces. */
+export const $workspaceMode = atom<WorkspaceMode>('sessions')
+
+/** Default workspace owner key: none (unscoped / global ownership). */
+export const $workspaceOwnerKey = atom<string | null>(null)
+
+/** One key for window-local active-pane memory. Owner keys stay opaque. */
+export function workspaceScopeKey(mode: WorkspaceMode, ownerKey: string | null): string {
+  return mode === 'sessions' ? 'sessions' : `bots:${ownerKey ?? ''}`
+}
+
+/** Publish one coherent presentation scope without an intermediate mixed frame. */
+export function setWorkspaceScope(mode: WorkspaceMode, ownerKey: string | null = null): boolean {
+  const nextOwnerKey = mode === 'bots' ? ownerKey : null
+
+  if ($workspaceMode.get() === mode && $workspaceOwnerKey.get() === nextOwnerKey) {
+    return false
+  }
+
+  batch(() => {
+    $workspaceMode.set(mode)
+    $workspaceOwnerKey.set(nextOwnerKey)
+  })
+
+  return true
+}
+
+/**
+ * The slice of {@link Contribution} metadata that scopes it to a workspace.
+ * A contribution with neither field set is global: it participates in every
+ * workspace, preserving pre-existing behavior.
+ */
+export interface WorkspaceScope {
+  /** Surface this contribution belongs to. Omit for global visibility. */
+  workspaceMode?: WorkspaceMode
+  /** Exact opaque owner key within the `'bots'` surface. Ignored otherwise. */
+  workspaceOwnerKey?: string
+}
+
+/**
+ * Whether a contribution participates in the given workspace.
+ *
+ * - Unscoped/global (no `workspaceMode`) => always participates.
+ * - Scoped with a mode mismatch => does not participate.
+ * - Sessions match => participates.
+ * - Bots match => participates only when the owner key is non-empty and equals
+ *   the current owner key (exact string equality).
+ *
+ * Defaults reflect the un-switched window state when omitted.
+ */
+export function contributesToWorkspace(
+  scope: WorkspaceScope | undefined,
+  mode: WorkspaceMode = $workspaceMode.get(),
+  ownerKey: string | null = $workspaceOwnerKey.get()
+): boolean {
+  const { workspaceMode, workspaceOwnerKey } = scope ?? {}
+
+  if (workspaceMode == null) {
+    return true
+  }
+
+  if (workspaceMode !== mode) {
+    return false
+  }
+
+  if (workspaceMode === 'sessions') {
+    return true
+  }
+
+  return Boolean(workspaceOwnerKey) && workspaceOwnerKey === ownerKey
+}
+
+/**
+ * Filter contributions down to those participating in the given workspace,
+ * preserving input order.
+ *
+ * Preserves reference identity on a no-op (every contribution participates),
+ * so callers can hand the result straight to React without a wasted re-render.
+ */
+export function filterContributionsForWorkspace<T extends WorkspaceScope>(
+  contributions: readonly T[],
+  mode: WorkspaceMode,
+  ownerKey: string | null
+): readonly T[] {
+  let filtered: T[] | null = null
+
+  for (let i = 0; i < contributions.length; i += 1) {
+    if (contributesToWorkspace(contributions[i], mode, ownerKey)) {
+      filtered?.push(contributions[i])
+
+      continue
+    }
+
+    filtered ??= contributions.slice(0, i)
+  }
+
+  return filtered ?? contributions
+}
+
+/**
+ * Window-local memory of the active pane per exact workspace owner key.
+ * Keys are opaque exact strings; similar-looking keys never collide because
+ * nothing here parses them.
+ */
+const rememberedActivePanes = new Map<string, string>()
+
+/** Remember which pane was active for an exact owner key. */
+export function rememberActivePane(ownerKey: string, paneId: string): void {
+  rememberedActivePanes.set(ownerKey, paneId)
+}
+
+/**
+ * Resolve the pane to activate for an owner key against the currently eligible
+ * panes. A remembered pane that has since been removed must not restore: the
+ * fallback is the first eligible pane, or null when none are eligible.
+ */
+export function resolveRememberedActivePane(
+  ownerKey: string,
+  eligiblePaneIds: readonly string[]
+): string | null {
+  const remembered = rememberedActivePanes.get(ownerKey)
+
+  if (remembered != null && eligiblePaneIds.includes(remembered)) {
+    return remembered
+  }
+
+  return eligiblePaneIds[0] ?? null
+}
+
+/** Forget the remembered pane for one owner key. */
+export function forgetActivePane(ownerKey: string): void {
+  rememberedActivePanes.delete(ownerKey)
+}
+
+/** Forget a pane removed from the layout, regardless of which owners used it. */
+export function forgetRememberedPane(paneId: string): void {
+  for (const [ownerKey, rememberedPaneId] of rememberedActivePanes) {
+    if (rememberedPaneId === paneId) {
+      rememberedActivePanes.delete(ownerKey)
+    }
+  }
+}
+
+/** Test-only: clear all remembered panes. */
+export function resetRememberedActivePanes(): void {
+  rememberedActivePanes.clear()
+}

apps/desktop/src/contrib/index.ts

@@ -3,4 +3,4 @@ export type { SlotProps } from './react/slot'
 
 export { useContributions } from './react/use-contributions'
 export { registry } from './registry'
-export type { Contribution, ContributionSource } from './types'
+export type { Contribution, ContributionSource, WorkspaceMode } from './types'

apps/desktop/src/contrib/types.ts

@@ -9,6 +9,13 @@ import type { ReactNode } from 'react'
  */
 export type ContributionSource = 'core' | (string & {})
 
+/**
+ * Which workspace surface a contribution targets. `'sessions'` is the classic
+ * session workspace; `'bots'` scopes content to an individual bot identified
+ * by an opaque owner key.
+ */
+export type WorkspaceMode = 'sessions' | 'bots'
+
 /**
  * The single, uniform primitive every surface consumes. A bar renders these as
  * inline items via `<Slot>`; a dock renders them as stacked/tabbed panes via
@@ -40,4 +47,16 @@ export interface Contribution {
    * themes, commands — anything consumed by an engine rather than rendered.
    */
   data?: unknown
+  /**
+   * Which workspace surface this contribution belongs to. Omit for a global
+   * contribution that participates in every workspace (pre-existing behavior).
+   * Presentation ownership hint only.
+   */
+  workspaceMode?: WorkspaceMode
+  /**
+   * Exact opaque owner key within the `'bots'` surface (e.g. a
+   * connection-qualified profile id). Never parsed here; compared exactly.
+   * Presentation ownership hint only.
+   */
+  workspaceOwnerKey?: string
 }

apps/desktop/src/sdk/index.test.ts

@@ -173,3 +173,45 @@ describe('host.connections', () => {
     await expect(host.connections()).rejects.toThrow('This Desktop build has no connection registry')
   })
 })
+
+describe('host workspace scope', () => {
+  afterEach(async () => {
+    host.setWorkspaceScope('sessions')
+    const tree = await import('@/components/pane-shell/tree/store')
+    tree.removeTreePane('plugin-workspace:scope-test')
+  })
+
+  it('registers plugin workspace ownership and chrome options', async () => {
+    const { registry } = await import('@/contrib/registry')
+
+    const close = host.openWorkspace('scope-test', {
+      dock: { pane: 'workspace', pos: 'right' },
+      headerVeto: true,
+      render: () => null,
+      title: 'Scoped',
+      uncloseable: true,
+      workspaceMode: 'bots',
+      workspaceOwnerKey: 'connection-a::default'
+    })
+
+    expect(registry.getArea('panes').find(pane => pane.id === 'plugin-workspace:scope-test')).toMatchObject({
+      data: {
+        dock: { pane: 'workspace', pos: 'right' },
+        headerVeto: true,
+        uncloseable: true
+      },
+      workspaceMode: 'bots',
+      workspaceOwnerKey: 'connection-a::default'
+    })
+
+    close()
+  })
+
+  it('publishes the active workspace scope through one host seam', async () => {
+    const { $workspaceMode, $workspaceOwnerKey } = await import('@/components/pane-shell/workspace-scope')
+
+    expect(host.setWorkspaceScope('bots', 'connection-b::default')).toBe(true)
+    expect($workspaceMode.get()).toBe('bots')
+    expect($workspaceOwnerKey.get()).toBe('connection-b::default')
+  })
+})

apps/desktop/src/sdk/index.ts

@@ -31,8 +31,10 @@ import {
   removeTreePane,
   revealTreePane
 } from '@/components/pane-shell/tree/store'
+import { setWorkspaceScope as publishWorkspaceScope } from '@/components/pane-shell/workspace-scope'
 import { onGatewayEvent } from '@/contrib/events'
 import { registry } from '@/contrib/registry'
+import type { WorkspaceMode } from '@/contrib/types'
 import { deleteProfile, getLogs, getStatus, type HermesGateway } from '@/hermes'
 import {
   $gateway,
@@ -285,6 +287,8 @@ export interface PluginOpenSessionOptions {
   keepAllProfilesScope?: boolean
   profile?: null | string
   route?: PluginProfileRoute
+  workspaceMode?: WorkspaceMode
+  workspaceOwnerKey?: string
   /** A cold profile backend can lose the hydration-timeout race once and still
    *  be fine on a second try. When set, a hydration timeout is retried
    *  internally before it reaches the caller or arms the core stranded-session
@@ -730,19 +734,26 @@ export const host = {
       // again inside the same wake — that is the Retry surface's job.
       for (let attempt = 1; attempt <= maxAttempts; attempt++) {
         try {
-          openSession(
-            storedSessionId,
-            (to: string, opts?: { replace?: boolean }) => {
-              const target = to.startsWith('#') ? to : `#${to}`
+          const navigate = (to: string, opts?: { replace?: boolean }) => {
+            const target = to.startsWith('#') ? to : `#${to}`
 
-              if (opts?.replace) {
-                window.location.replace(target)
-              } else {
-                window.location.hash = target
-              }
-            },
-            options.intent ?? 'in-place'
-          )
+            if (opts?.replace) {
+              window.location.replace(target)
+            } else {
+              window.location.hash = target
+            }
+          }
+
+          const intent = options.intent ?? 'in-place'
+
+          if (options.workspaceMode === 'bots') {
+            openSession(storedSessionId, navigate, intent, {
+              workspaceMode: 'bots',
+              workspaceOwnerKey: options.workspaceOwnerKey
+            })
+          } else {
+            openSession(storedSessionId, navigate, intent)
+          }
 
           // Judge the main surface AFTER the open: on a cold start the persisted
           // route can already point at this session while selection has not
@@ -846,7 +857,17 @@ export const host = {
    *  fallback. */
   openWorkspace: (
     id: string,
-    options: { minWidth?: string; onClose?: () => void; render: () => ReactNode; title?: string }
+    options: {
+      dock?: { before?: null | string; pane: string; pos: 'bottom' | 'center' | 'left' | 'right' | 'top' }
+      headerVeto?: boolean
+      minWidth?: string
+      onClose?: () => void
+      render: () => ReactNode
+      title?: string
+      uncloseable?: boolean
+      workspaceMode?: WorkspaceMode
+      workspaceOwnerKey?: string
+    }
   ): (() => void) => {
     const key = (id ?? '').trim()
 
@@ -861,13 +882,17 @@ export const host = {
       data: {
         // The session-tile shape: a full workspace surface docked beside main,
         // closeable so it keeps its tab when it lands in a zone of its own.
-        dock: { pane: 'workspace', pos: 'center' },
+        dock: options.dock ?? { pane: 'workspace', pos: 'center' },
+        headerVeto: options.headerVeto,
         minWidth: options.minWidth ?? '22rem',
-        placement: 'main'
+        placement: 'main',
+        uncloseable: options.uncloseable
       },
       id: paneId,
       render: options.render,
-      title: options.title ?? key
+      title: options.title ?? key,
+      workspaceMode: options.workspaceMode,
+      workspaceOwnerKey: options.workspaceOwnerKey
     })
 
     const close = () => {
@@ -886,6 +911,10 @@ export const host = {
     return close
   },
 
+  /** Switch the visible main-pane workspace without unregistering retained panes. */
+  setWorkspaceScope: (mode: WorkspaceMode, ownerKey: null | string = null): boolean =>
+    publishWorkspaceScope(mode, ownerKey),
+
   /** Start a fresh chat draft, optionally pointed at another profile (its
    *  backend spins up in the background — same door the sidebar's per-profile
    *  "+" uses). */

apps/desktop/src/sdk/profile-routing.test.ts

@@ -413,6 +413,26 @@ describe('profile-aware plugin session opens', () => {
     expect(openSessionCore).toHaveBeenCalledWith('remote-chat', expect.any(Function), 'in-place')
   })
 
+  it('threads an exact Bot workspace owner into the core session open', async () => {
+    const route = {
+      connectionId: 'source-a',
+      mode: 'remote' as const,
+      profile: 'default',
+      targetProfile: 'backend-default'
+    }
+
+    await host.openSession('bot-chat', {
+      route,
+      workspaceMode: 'bots',
+      workspaceOwnerKey: 'source-a::default'
+    })
+
+    expect(openSessionCore).toHaveBeenCalledWith('bot-chat', expect.any(Function), 'in-place', {
+      workspaceMode: 'bots',
+      workspaceOwnerKey: 'source-a::default'
+    })
+  })
+
   it('waits until the target Bot Chat runtime and history are on main before resolving', async () => {
     vi.mocked(openGatewayForProfile).mockImplementationOnce(async () => undefined)
 

apps/desktop/src/store/session-states.test.ts

@@ -12,12 +12,15 @@ import {
   focusedSessionNeedsRoute,
   markSelectionRestore,
   nextSessionTileForWorkspace,
+  openSessionTile,
   orderTilesByTree,
+  patchSessionTile,
   releaseSessionTranscript,
   resetTileRuntimeBindings,
   selectionHomesToWorkspace,
   type SessionTileDelegate,
-  setSessionTileDelegate
+  setSessionTileDelegate,
+  setSessionTileWorkspaceScope
 } from '@/store/session-states'
 
 const tile = (storedSessionId: string): SessionTile => ({ storedSessionId })
@@ -53,6 +56,69 @@ describe('resetTileRuntimeBindings', () => {
   })
 })
 
+describe('SessionTile workspace scope', () => {
+  afterEach(() => {
+    $layoutTree.set(null)
+    $selectedStoredSessionId.set(null)
+    $sessionTiles.set([])
+  })
+
+  it('stores an exact Bot owner and keeps it through placement patches', () => {
+    const scope = { workspaceMode: 'bots' as const, workspaceOwnerKey: 'connection-a::default' }
+
+    openSessionTile('bot-chat', 'right', undefined, undefined, scope)
+    patchSessionTile('bot-chat', { dir: 'left' })
+
+    expect($sessionTiles.get()).toEqual([
+      expect.objectContaining({
+        dir: 'left',
+        storedSessionId: 'bot-chat',
+        workspaceMode: 'bots',
+        workspaceOwnerKey: 'connection-a::default'
+      })
+    ])
+  })
+
+  it('re-scopes an existing tile without changing its placement', () => {
+    openSessionTile('chat', 'bottom', 'workspace')
+
+    expect(
+      setSessionTileWorkspaceScope('chat', {
+        workspaceMode: 'bots',
+        workspaceOwnerKey: 'connection-b::default'
+      })
+    ).toBe(true)
+    expect($sessionTiles.get()[0]).toMatchObject({
+      anchor: 'workspace',
+      dir: 'bottom',
+      workspaceMode: 'bots',
+      workspaceOwnerKey: 'connection-b::default'
+    })
+  })
+
+  it('preserves workspace scope while dropping a stale runtime binding', () => {
+    $sessionTiles.set([
+      {
+        runtimeId: 'runtime-dead',
+        storedSessionId: 'bot-chat',
+        workspaceMode: 'bots',
+        workspaceOwnerKey: 'connection-a::default'
+      }
+    ])
+
+    resetTileRuntimeBindings()
+
+    expect($sessionTiles.get()[0]).toEqual({
+      anchor: undefined,
+      before: undefined,
+      dir: undefined,
+      storedSessionId: 'bot-chat',
+      workspaceMode: 'bots',
+      workspaceOwnerKey: 'connection-a::default'
+    })
+  })
+})
+
 describe('releaseSessionTranscript', () => {
   afterEach(() => {
     $sessionStates.set({})

apps/desktop/src/store/session-states.ts

@@ -29,6 +29,7 @@ import {
   noteActiveTreeGroup,
   revealTreePane
 } from '@/components/pane-shell/tree/store'
+import type { WorkspaceMode } from '@/contrib/types'
 import { stableArray } from '@/lib/stable-array'
 import { readJson, writeJson } from '@/lib/storage'
 import type { SessionInfo } from '@/types/hermes'
@@ -535,6 +536,15 @@ export interface SessionTile {
   runtimeId?: string
   /** Resume failed terminally (shown in the tile; retryable). */
   error?: string
+  /** Presentation workspace this tab belongs to. Missing legacy values are Sessions. */
+  workspaceMode?: WorkspaceMode
+  /** Exact opaque owner key for Bot Mode tabs. */
+  workspaceOwnerKey?: string
+}
+
+export interface SessionTileWorkspaceScope {
+  workspaceMode: WorkspaceMode
+  workspaceOwnerKey?: string
 }
 
 // Tiles are persisted PER PROFILE: a session belongs to one profile, and the
@@ -550,13 +560,18 @@ const TILE_PANE_PREFIX = 'session-tile:'
 /** Persisted placement — `dir` + strip slot (`before`) + dock `anchor` so a
  *  restart / profile swap re-adopts tiles in the same order, not all stacked
  *  right of workspace. */
-type StoredTile = Pick<SessionTile, 'anchor' | 'before' | 'dir' | 'storedSessionId'>
+type StoredTile = Pick<
+  SessionTile,
+  'anchor' | 'before' | 'dir' | 'storedSessionId' | 'workspaceMode' | 'workspaceOwnerKey'
+>
 
 const toStored = (t: SessionTile): StoredTile => ({
   anchor: t.anchor,
   before: t.before,
   dir: t.dir,
-  storedSessionId: t.storedSessionId
+  storedSessionId: t.storedSessionId,
+  ...(t.workspaceMode ? { workspaceMode: t.workspaceMode } : {}),
+  ...(t.workspaceOwnerKey ? { workspaceOwnerKey: t.workspaceOwnerKey } : {})
 })
 
 function parseTileList(value: unknown): StoredTile[] {
@@ -570,7 +585,12 @@ function parseTileList(value: unknown): StoredTile[] {
             anchor: typeof raw.anchor === 'string' ? raw.anchor : undefined,
             before: typeof raw.before === 'string' || raw.before === null ? raw.before : undefined,
             dir: raw.dir,
-            storedSessionId: raw.storedSessionId
+            storedSessionId: raw.storedSessionId,
+            workspaceMode: raw.workspaceMode === 'bots' ? 'bots' : 'sessions',
+            workspaceOwnerKey:
+              raw.workspaceMode === 'bots' && typeof raw.workspaceOwnerKey === 'string'
+                ? raw.workspaceOwnerKey
+                : undefined
           }
         })
     : []
@@ -653,6 +673,25 @@ export function patchSessionTile(storedSessionId: string, patch: Partial<Session
   saveTiles($sessionTiles.get().map(t => (t.storedSessionId === storedSessionId ? { ...t, ...patch } : t)))
 }
 
+export function setSessionTileWorkspaceScope(
+  storedSessionId: string,
+  scope: SessionTileWorkspaceScope
+): boolean {
+  const tile = $sessionTiles.get().find(candidate => candidate.storedSessionId === storedSessionId)
+  const workspaceOwnerKey = scope.workspaceMode === 'bots' ? scope.workspaceOwnerKey : undefined
+
+  if (
+    !tile ||
+    ((tile.workspaceMode ?? 'sessions') === scope.workspaceMode && tile.workspaceOwnerKey === workspaceOwnerKey)
+  ) {
+    return false
+  }
+
+  patchSessionTile(storedSessionId, { workspaceMode: scope.workspaceMode, workspaceOwnerKey })
+
+  return true
+}
+
 /** Drop live runtime bindings so every tile re-resumes — used on gateway
  *  reconnect, where a respawned backend re-mints (recycles) runtime ids.
  *  Also invalidates the wiring cache's stored→runtime map: clearing only the
@@ -795,7 +834,8 @@ export function openSessionTile(
   storedSessionId: string,
   dir: TileDock = 'right',
   anchor?: string,
-  before?: null | string
+  before?: null | string,
+  workspaceScope: SessionTileWorkspaceScope = { workspaceMode: 'sessions' }
 ) {
   const tiles = $sessionTiles.get()
 
@@ -813,14 +853,29 @@ export function openSessionTile(
 
   const dock = anchor ?? focusedSessionTabAnchor() ?? undefined
 
+  const workspaceOwnerKey =
+    workspaceScope.workspaceMode === 'bots' ? workspaceScope.workspaceOwnerKey : undefined
+
   if (!tiles.some(t => t.storedSessionId === storedSessionId)) {
-    saveTiles([...tiles, { anchor: dock, before, dir, storedSessionId }])
+    saveTiles([
+      ...tiles,
+      {
+        anchor: dock,
+        before,
+        dir,
+        storedSessionId,
+        workspaceMode: workspaceScope.workspaceMode,
+        workspaceOwnerKey
+      }
+    ])
     // Adoption is async via the registry — order sync runs after the move path
     // below; a brand-new tile's strip slot is already in `before`.
 
     return
   }
 
+  setSessionTileWorkspaceScope(storedSessionId, workspaceScope)
+
   // Already open: relocate the existing pane to the drop target (pane-mirror
   // only docks on first adoption, so a re-drag must move the tree pane itself).
   const tree = $layoutTree.get()
@@ -940,7 +995,10 @@ export function blankDraftTile(
  *  False when there's no such tab, so the caller can fall back. The spent draft
  *  is DISCARDED rather than closed: it never held a conversation, so ⌘⇧T
  *  resurrecting it would just restore an empty tab. */
-export function reuseBlankDraftTile(storedSessionId: string): boolean {
+export function reuseBlankDraftTile(
+  storedSessionId: string,
+  workspaceScope: SessionTileWorkspaceScope = { workspaceMode: 'sessions' }
+): boolean {
   const tile = blankDraftTile($sessionTiles.get(), $sessionStates.get())
 
   if (!tile || tile.storedSessionId === storedSessionId) {
@@ -948,7 +1006,7 @@ export function reuseBlankDraftTile(storedSessionId: string): boolean {
   }
 
   discardSessionTile(tile.storedSessionId)
-  openSessionTile(storedSessionId, tile.dir, tile.anchor, tile.before)
+  openSessionTile(storedSessionId, tile.dir, tile.anchor, tile.before, workspaceScope)
   revealTreePane(`${TILE_PANE_PREFIX}${storedSessionId}`)
 
   return true
@@ -964,7 +1022,7 @@ export function closeSessionTile(storedSessionId: string) {
   const tile = $sessionTiles.get().find(t => t.storedSessionId === storedSessionId)
 
   if (tile) {
-    closedStack().push({ anchor: tile.anchor, before: tile.before, dir: tile.dir, storedSessionId })
+    closedStack().push(toStored(tile))
   }
 
   saveTiles($sessionTiles.get().filter(t => t.storedSessionId !== storedSessionId))
@@ -1011,7 +1069,10 @@ export function reopenLastClosedTile(): void {
     }
 
     if (!$sessionTiles.get().some(t => t.storedSessionId === storedSessionId)) {
-      openSessionTile(storedSessionId, tile.dir, tile.anchor, tile.before)
+      openSessionTile(storedSessionId, tile.dir, tile.anchor, tile.before, {
+        workspaceMode: tile.workspaceMode ?? 'sessions',
+        workspaceOwnerKey: tile.workspaceOwnerKey
+      })
       focusOpenSession(storedSessionId)
 
       return