@@ -4,6 +4,7 @@ import { useEffect, useRef } from 'react'
 import { useToast } from '@sim/emcn'
 import { assessTextPaste, formatPasteLimit, PASTE_LIMITS } from '@sim/utils/paste'
 import { readSelectionContextFromClipboard } from '@/lib/mothership/chat/selection-clipboard'
+import { FileOperationOwner } from '@/lib/mothership/generated/file-owner'
 
 const EDITABLE_TARGET_SELECTOR =
   'input:not([type="file"]):not([type="checkbox"]):not([type="radio"]):not([type="button"]):not([type="submit"]):not([type="hidden"]), textarea, [contenteditable]:not([contenteditable="false"]), .monaco-editor, .xterm'
@@ -23,6 +24,27 @@ function clipboardHasImageFile(data: DataTransfer | null): boolean {
   )
 }
 
+function selectionOwnerHints(element: Element | null): FileOperationOwner[] {
+  const encoded = element?.getAttribute('data-paste-selection-owners')
+  if (encoded !== null && encoded !== undefined) {
+    try {
+      const parsed: unknown = JSON.parse(encoded)
+      if (!Array.isArray(parsed)) return []
+      const owners: FileOperationOwner[] = []
+      for (const candidate of parsed) {
+        const owner = FileOperationOwner.safeParse(candidate)
+        if (!owner.success) return []
+        owners.push(owner.data)
+      }
+      return owners
+    } catch {
+      return []
+    }
+  }
+  const workspaceId = element?.getAttribute('data-paste-selection-context')
+  return workspaceId ? [{ entityType: 'workspace', entityId: workspaceId }] : []
+}
+
 /**
  * Last-resort admission for every editable workspace surface. Specialized editors publish their
  * downstream ceiling on an ancestor with `data-paste-max-bytes`; controls without one inherit a
@@ -42,13 +64,15 @@ export function PasteAdmissionGuard() {
         return
       }
 
-      const acceptsSelectionContext = event.target.closest('[data-paste-selection-context]')
-      const destinationWorkspaceId = acceptsSelectionContext?.getAttribute(
-        'data-paste-selection-context'
+      const acceptsSelectionContext = event.target.closest(
+        '[data-paste-selection-owners], [data-paste-selection-context]'
       )
       if (
-        destinationWorkspaceId &&
-        readSelectionContextFromClipboard(event.clipboardData, destinationWorkspaceId)
+        acceptsSelectionContext &&
+        readSelectionContextFromClipboard(
+          event.clipboardData,
+          selectionOwnerHints(acceptsSelectionContext)
+        )
       ) {
         return
       }
 
@@ -20,6 +20,7 @@ import {
   createInternalServerErrorResponse,
   createUnauthorizedResponse,
 } from '@/lib/mothership/request/http'
+import { presentChatResourceForBrowser } from '@/lib/mothership/resources/presentation'
 import {
   assertActiveWorkspaceAccess,
   isWorkspaceAccessDeniedError,
@@ -49,7 +50,11 @@ function transformChat(chat: {
     effort: chat.effort ?? null,
     ...('conversationId' in chat ? { activeStreamId: chat.conversationId || null } : {}),
     ...('resources' in chat
-      ? { resources: Array.isArray(chat.resources) ? chat.resources : [] }
+      ? {
+          resources: Array.isArray(chat.resources)
+            ? chat.resources.map(presentChatResourceForBrowser)
+            : [],
+        }
       : {}),
     createdAt: chat.createdAt,
     updatedAt: chat.updatedAt,
 
@@ -5,12 +5,13 @@ import {
 } from '@/lib/api/contracts/copilot'
 import {
   defineInternalJsonRoute,
-  internalJsonPresenters,
   internalOrchestrationErrorPolicy,
   internalRateLimits,
   internalSessionAuth,
 } from '@/lib/api/server/routes'
 import { changeChatResources } from '@/lib/mothership/chat/application/change-resources'
+import { presentChatResourceForBrowser } from '@/lib/mothership/resources/presentation'
+import type { MothershipResource } from '@/lib/mothership/resources/types'
 
 const policy = {
   auth: internalSessionAuth,
@@ -20,7 +21,10 @@ const policy = {
   }),
   errorPolicy: internalOrchestrationErrorPolicy,
   useCase: changeChatResources,
-  present: internalJsonPresenters.withSuccess,
+  present: ({ resources }: { resources: MothershipResource[] }) => ({
+    success: true as const,
+    resources: resources.map(presentChatResourceForBrowser),
+  }),
 }
 
 export const POST = defineInternalJsonRoute({
@@ -53,7 +57,14 @@ export const DELETE = defineInternalJsonRoute({
     chatId: body.chatId,
     change: {
       kind: 'remove' as const,
-      resources: [{ type: body.resourceType, id: body.resourceId, workspaceId: body.workspaceId }],
+      resources: [
+        {
+          type: body.resourceType,
+          id: body.resourceId,
+          workspaceId: body.workspaceId,
+          owner: body.owner,
+        },
+      ],
     },
   }),
 })
@@ -29,6 +29,7 @@ import {
   createInternalServerErrorResponse,
   createUnauthorizedResponse,
 } from '@/lib/mothership/request/http'
+import { presentChatResourceForBrowser } from '@/lib/mothership/resources/presentation'
 import { captureServerEvent } from '@/lib/posthog/server'
 
 const logger = createLogger('MothershipChatAPI')
@@ -107,7 +108,9 @@ export const GET = withRouteHandler(
           mode: chat.mode,
           messages: effectiveMessages,
           activeStreamId: liveStreamId,
-          resources: Array.isArray(chat.resources) ? chat.resources : [],
+          resources: Array.isArray(chat.resources)
+            ? chat.resources.map(presentChatResourceForBrowser)
+            : [],
           effort: chat.effort,
           olderCursor: chat.olderCursor,
           windowStartCursor: chat.windowStartCursor,
 
@@ -51,6 +51,7 @@ const mocks = vi.hoisted(() => ({
 vi.mock('@/lib/core/config/deployment-shape', () => deploymentShapeMock)
 vi.mock('@/hooks/queries/workspace', () => ({
   useWorkspacesQuery: () => ({ data: mocks.workspaces }),
+  useOrderedWorkspacesQuery: () => ({ data: mocks.workspaces }),
 }))
 vi.mock('@/hooks/queries/skills', () => ({
   useSkills: () => ({ data: [] }),
@@ -240,6 +241,7 @@ async function render(
             changelog: false,
             'mothership-model-selector': mocks.advanced,
             'mothership-plan-mode': mocks.plan,
+            projects: false,
           }}
         >
           <Harness />
@@ -319,6 +321,7 @@ it.each([
               changelog: false,
               'mothership-model-selector': false,
               'mothership-plan-mode': planEnabled,
+              projects: false,
             }}
           >
             <Harness />
@@ -415,6 +418,7 @@ it('keeps restored queued skills scoped when replacing a draft', async () => {
             changelog: false,
             'mothership-model-selector': mocks.advanced,
             'mothership-plan-mode': mocks.plan,
+            projects: false,
           }}
         >
           <Harness />
 
@@ -1,6 +1,7 @@
 /** @vitest-environment jsdom */
 
 import { act, type ComponentProps, type ReactNode } from 'react'
+import { toast } from '@sim/emcn'
 import { authClientMock, authClientMockFns } from '@sim/testing/mocks/auth-client.mock'
 import {
   createMockDeploymentShape,
@@ -9,7 +10,6 @@ import {
 } from '@sim/testing/mocks/deployment-shape.mock'
 import { integrationMatcherMock } from '@sim/testing/mocks/integration-matcher.mock'
 import { kbConnectorsQueriesMock } from '@sim/testing/mocks/kb-connectors-queries.mock'
-import { nextNavigationMock } from '@sim/testing/mocks/next-navigation.mock'
 import {
   organizationProviderMock,
   organizationProviderMockFns,
@@ -24,6 +24,7 @@ import { useOrganizationChatModeStore } from '@/stores/organization-chat-mode/st
 
 const mocks = vi.hoisted(() => ({
   plan: false,
+  projects: true,
   resourcePanel: vi.fn(),
   chat: vi.fn(),
   composer: vi.fn(),
@@ -40,11 +41,15 @@ const mocks = vi.hoisted(() => ({
   activeResource: null as string | null,
 }))
 vi.mock('@/app/workspace/[workspaceId]/providers/feature-flags-provider', () => ({
-  useFeatureFlag: (name: string) => (name === 'mothership-plan-mode' ? mocks.plan : false),
+  useFeatureFlag: (name: string) =>
+    name === 'mothership-plan-mode' ? mocks.plan : name === 'projects' ? mocks.projects : false,
 }))
 vi.mock('@/lib/core/config/deployment-shape', () => deploymentShapeMock)
 vi.mock('@/blocks/integration-matcher', () => integrationMatcherMock)
-vi.mock('next/navigation', () => nextNavigationMock)
+vi.mock(
+  'next/navigation',
+  async () => (await import('@sim/testing/mocks/next-navigation.mock')).nextNavigationMock
+)
 vi.mock('@tanstack/react-query', () => reactQueryMock)
 vi.mock('@/app/workspace/[workspaceId]/home/hooks/use-resource-panel', () => ({
   useResourcePanelController: () => ({
@@ -103,6 +108,7 @@ let root: Root
 let container: HTMLDivElement
 beforeEach(() => {
   useMothershipDraftsStore.setState({ drafts: {} })
+  mocks.projects = true
   mocks.plan = false
   mocks.activeResource = null
   mockSession.mockReturnValue({ data: { user: { id: 'reader' } } })
@@ -224,3 +230,28 @@ it('isolates saved drafts by user, organization, and conversation', async () =>
   await act(async () => renderHome(<OrganizationHome chatId='chat-a' requestMode='assistant' />))
   expect(composerProps().value).toBe('')
 })
+
+it.each([false])('does not look up saved Project references with projects=%s', async (projects) => {
+  mocks.projects = projects
+  vi.spyOn(toast, 'error').mockReturnValue('lookup-error')
+  const requests: unknown[] = []
+  const resources: unknown[] = []
+  vi.stubGlobal('fetch', async (input: unknown) => {
+    requests.push(input)
+    throw new Error('Project lookup is disabled')
+  })
+  mocks.addResource.mockImplementation((resource: unknown) => resources.push(resource))
+  await act(async () => renderHome(<OrganizationHome chatId='chat-a' />))
+  const selectResource = mocks.renderer.mock.lastCall?.[0].onWorkspaceResourceSelect
+  if (!selectResource) throw new Error('Chat resource selection is unavailable')
+  await act(async () =>
+    selectResource({
+      type: 'file',
+      id: 'file-a',
+      title: 'Saved Project file',
+      owner: { entityType: 'project', entityId: 'project-a' },
+    })
+  )
+  expect(requests).toEqual([])
+  expect(resources).toEqual([])
+})
@@ -7,6 +7,7 @@ import Link from 'next/link'
 import { useQueryStates } from 'nuqs'
 import { requestJson } from '@/lib/api/client/request'
 import type { WorkspaceSearchFilters } from '@/lib/api/contracts/knowledge'
+import { getProjectContract } from '@/lib/api/contracts/projects'
 import { getWorkspaceHostContextContract } from '@/lib/api/contracts/workspaces'
 import { useSession } from '@/lib/auth/client'
 import { MothershipHandoffStorage } from '@/lib/core/utils/browser-storage'
@@ -47,7 +48,8 @@ import { useFeatureFlag } from '@/app/workspace/[workspaceId]/providers/feature-
 import { useFileAttachments } from '@/app/workspace/[workspaceId]/w/[workflowId]/components/panel/components/copilot/components/user-input/hooks/use-file-attachments'
 import { mentionifyIntegrations } from '@/blocks/integration-matcher'
 import { useMarkMothershipChatRead } from '@/hooks/queries/mothership-chats'
-import { getWorkspaceFilesQueryOptions } from '@/hooks/queries/workspace-files'
+import { getProjectFileQueryOptions } from '@/hooks/queries/project-files'
+import { getWorkspaceFilesQueryOptions } from '@/hooks/queries/utils/workspace-file-query'
 import { useHydrated } from '@/hooks/use-hydrated'
 import { useMothershipDraftsStore } from '@/stores/mothership-drafts/store'
 import { useOrganizationChatModeStore } from '@/stores/organization-chat-mode/store'
@@ -92,6 +94,8 @@ function OrganizationHomeContent({
   const rememberMode = useOrganizationChatModeStore((state) => state.setMode)
   const [selectedMode, setSelectedMode] = useState<ChatRequestMode | null>(null)
   const planEnabled = useFeatureFlag('mothership-plan-mode')
+  const projectsEnabled = useFeatureFlag('projects')
+
   const requestMode =
     selectedMode ??
     (urlSearchLevel && searchAccess.memberScoped && !chatId ? 'assistant' : undefined) ??
@@ -168,11 +172,30 @@ function OrganizationHomeContent({
   ])
   const selectResource = useCallback(
     async (ref: WorkspaceResourceRef) => {
-      if (!ref.workspaceId) {
-        toast.error('This resource has no workspace address.')
-        return
-      }
       try {
+        if (ref.type === 'file' && ref.owner?.entityType === 'project') {
+          if (!projectsEnabled) return
+          if (!ref.id) throw new Error('Missing Project file identity')
+          await requestJson(getProjectContract, {
+            params: { id: ref.owner.entityId },
+            query: { organizationId: organization.id },
+          })
+          const result = await queryClient.fetchQuery({
+            ...getProjectFileQueryOptions(ref.owner.entityId, ref.id),
+            staleTime: 0,
+          })
+          addResource({
+            type: 'file',
+            id: result.file.id,
+            title: result.file.name,
+            owner: result.file.owner,
+          })
+          return
+        }
+        if (!ref.workspaceId) {
+          toast.error('This resource has no workspace address.')
+          return
+        }
         const host = await requestJson(getWorkspaceHostContextContract, {
           params: { id: ref.workspaceId },
         })
@@ -194,7 +217,7 @@ function OrganizationHomeContent({
         toast.error(`Couldn't open "${ref.title}". Check your access and try again.`)
       }
     },
-    [queryClient, addResource, organization.id]
+    [queryClient, addResource, organization.id, projectsEnabled]
   )
   const files = useFileAttachments({
     userId: session?.user?.id,
 
@@ -0,0 +1,38 @@
+import { notFound, redirect } from 'next/navigation'
+import { internalSessionAuth } from '@/lib/api/server/routes'
+import { getSession } from '@/lib/auth'
+import { isFeatureEnabled } from '@/lib/core/config/feature-flags'
+import { asOrchestrationError } from '@/lib/core/orchestration/types'
+import { getProject } from '@/lib/projects/application/use-cases'
+import { getProjectFileMetadata } from '@/lib/projects/files/application'
+
+interface ProjectFilePageProps {
+  params: Promise<{ projectId: string; fileId: string }>
+}
+
+/** Resolves a durable Project link into an environment the current viewer can access. */
+export default async function ProjectFilePage({ params }: ProjectFilePageProps) {
+  if (!(await isFeatureEnabled('projects'))) notFound()
+  const { projectId, fileId } = await params
+  if (!(await getSession())?.user) {
+    const destination = `/projects/${encodeURIComponent(projectId)}/files/${encodeURIComponent(fileId)}`
+    redirect(`/login?callbackUrl=${encodeURIComponent(destination)}`)
+  }
+  const principal = await internalSessionAuth.authenticate()
+  let workspaceId: string | undefined
+  try {
+    const [context] = await Promise.all([
+      getProject.execute({ principal, input: { projectId } }),
+      getProjectFileMetadata.execute({ principal, input: { projectId, fileId } }),
+    ])
+    workspaceId = context.project.environments[0]?.id
+  } catch (error) {
+    const classified = asOrchestrationError(error)
+    if (classified?.code === 'not_found' || classified?.code === 'forbidden') notFound()
+    throw error
+  }
+  if (!workspaceId) notFound()
+  redirect(
+    `/workspace/${encodeURIComponent(workspaceId)}/files/${encodeURIComponent(fileId)}?owner=project&projectId=${encodeURIComponent(projectId)}`
+  )
+}