@@ -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,
+        },
+      ],
     },
   }),
 })
@@ -30,6 +30,7 @@ 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,
 
@@ -5,20 +5,18 @@ import {
   v2RateLimiterModuleMock,
   v2RouteMocks,
 } from '@sim/testing'
+import {
+  readWorkspaceFileMetadataMock,
+  readWorkspaceFileMetadataMockFns,
+} from '@sim/testing/mocks/read-workspace-file-metadata.mock'
 import { usersQueriesMock, usersQueriesMockFns } from '@sim/testing/mocks/users-queries.mock'
 import { NextRequest } from 'next/server'
 import { beforeEach, describe, expect, it, vi } from 'vitest'
 
-const mocks = vi.hoisted(() => ({
-  readMetadata: vi.fn(),
-}))
-
-vi.mock('@/lib/workspace-files/application/read-workspace-file-metadata', () => ({
-  readWorkspaceFileMetadataWithVersion: {
-    operation: { id: 'files.read_metadata', minimumRole: 'read', workspaceApiKey: 'allow' },
-    execute: mocks.readMetadata,
-  },
-}))
+vi.mock(
+  '@/lib/workspace-files/application/read-workspace-file-metadata',
+  () => readWorkspaceFileMetadataMock
+)
 
 vi.mock('@/lib/api/server/routes/v2-api-key-auth', () => v2ApiKeyAuthModuleMock)
 vi.mock('@/lib/core/rate-limiter', () => v2RateLimiterModuleMock)
@@ -30,6 +28,7 @@ import { OrchestrationError } from '@/lib/core/orchestration/types'
 import { GET } from '@/app/api/v2/files/[fileId]/metadata/route'
 
 const { mockGetUserEmailsByIds } = usersQueriesMockFns
+const readMetadata = readWorkspaceFileMetadataMockFns.mockReadWorkspaceFileMetadataWithVersion
 
 const WORKSPACE_ID = 'workspace-1'
 const FILE_ID = 'wf_1'
@@ -89,15 +88,15 @@ describe('GET /api/v2/files/[fileId]/metadata', () => {
     v2RouteMocks.authenticate.mockResolvedValue(auth)
     v2RouteMocks.preauthRate.mockResolvedValue(V2_PREAUTH_RATE_LIMIT_ALLOWED)
     v2RouteMocks.operationRate.mockResolvedValue(V2_OPERATION_RATE_LIMIT_ALLOWED)
-    mocks.readMetadata.mockResolvedValue({
+    readMetadata.mockResolvedValue({
       file: { ...buildRecord(), currentVersion: 3 },
       share: SHARE,
     })
     mockGetUserEmailsByIds.mockResolvedValue(new Map([['user-1', 'ada@example.com']]))
   })
 
   it('conceals cross-workspace authorization as not found', async () => {
-    mocks.readMetadata.mockRejectedValue(new NoWorkspaceAccessError())
+    readMetadata.mockRejectedValue(new NoWorkspaceAccessError())
 
     const response = await callGet(`workspaceId=${WORKSPACE_ID}`)
 
@@ -106,35 +105,35 @@ describe('GET /api/v2/files/[fileId]/metadata', () => {
   })
 
   it('leaves an archived file unreachable when scope is omitted', async () => {
-    mocks.readMetadata.mockImplementation(archivedFileUseCase)
+    readMetadata.mockImplementation(archivedFileUseCase)
 
     const response = await callGet(`workspaceId=${WORKSPACE_ID}`)
 
     expect(response.status).toBe(404)
     expect((await response.json()).error.code).toBe('NOT_FOUND')
-    expect(mocks.readMetadata).toHaveBeenCalledWith(
+    expect(readMetadata).toHaveBeenCalledWith(
       expect.objectContaining({
         input: { fileId: FILE_ID, assertedWorkspaceId: WORKSPACE_ID, includeDeleted: false },
       })
     )
   })
 
   it('leaves an archived file unreachable under an explicit scope=active', async () => {
-    mocks.readMetadata.mockImplementation(archivedFileUseCase)
+    readMetadata.mockImplementation(archivedFileUseCase)
 
     const response = await callGet(`workspaceId=${WORKSPACE_ID}&scope=active`)
 
     expect(response.status).toBe(404)
     expect((await response.json()).error.code).toBe('NOT_FOUND')
-    expect(mocks.readMetadata).toHaveBeenCalledWith(
+    expect(readMetadata).toHaveBeenCalledWith(
       expect.objectContaining({
         input: { fileId: FILE_ID, assertedWorkspaceId: WORKSPACE_ID, includeDeleted: false },
       })
     )
   })
 
   it('returns archived metadata when scope=archived opts into the archived set', async () => {
-    mocks.readMetadata.mockImplementation(archivedFileUseCase)
+    readMetadata.mockImplementation(archivedFileUseCase)
 
     const response = await callGet(`workspaceId=${WORKSPACE_ID}&scope=archived`)
 
@@ -157,7 +156,7 @@ describe('GET /api/v2/files/[fileId]/metadata', () => {
         revision: expect.any(String),
       },
     })
-    expect(mocks.readMetadata).toHaveBeenCalledWith(
+    expect(readMetadata).toHaveBeenCalledWith(
       expect.objectContaining({
         principal: auth.principal,
         input: { fileId: FILE_ID, assertedWorkspaceId: WORKSPACE_ID, includeDeleted: true },
 
@@ -11,10 +11,10 @@ import {
   v2OrchestrationErrorPolicy,
   v2RateLimits,
 } from '@/lib/api/server/routes'
+import { toCreateProjectFileInput } from '@/lib/projects/files/api'
 import { toV2ProjectFile } from '@/lib/projects/files/api/presenters'
 import { createProjectFile, listProjectFiles } from '@/lib/projects/files/application'
 import { projectFileOperations } from '@/lib/projects/files/application/operations'
-import { getFileExtension, getMimeTypeFromExtension } from '@/lib/uploads/utils/file'
 import { MAX_WORKSPACE_FILE_INLINE_BODY_BYTES } from '@/lib/workspace-files/orchestration'
 import { readSortedCursor, writeSortedCursor } from '@/app/api/v2/lib/response'
 
@@ -68,15 +68,7 @@ export const POST = defineV2JsonRoute({
   rateLimit: v2RateLimits.publicApi,
   errorPolicy: v2OrchestrationErrorPolicy,
   parseOptions: { maxBodyBytes: MAX_WORKSPACE_FILE_INLINE_BODY_BYTES },
-  mapInput: ({ params, body }) => ({
-    projectId: params.projectId,
-    name: body.name,
-    contentType: body.contentType ?? getMimeTypeFromExtension(getFileExtension(body.name)),
-    content: body.content,
-    encoding: body.encoding,
-    folderPath: body.folderPath ?? '/',
-    exactName: true,
-  }),
+  mapInput: ({ params, body }) => toCreateProjectFileInput(params.projectId, body),
   useCase: createProjectFile,
   present: ({ file }) => ({ data: toV2ProjectFile(file) }),
 })
@@ -108,6 +108,10 @@ export const CHAT_CONTEXT_KIND_REGISTRY: Record<ChatContextKind, ChatContextKind
     label: 'File folder',
     renderIcon: ({ className }) => <FolderIcon className={className} />,
   },
+  project: {
+    label: 'Project',
+    renderIcon: ({ className }) => <FolderIcon className={className} />,
+  },
   workspace: {
     label: 'Workspace',
     renderIcon: ({ className }) => <Workspaces className={className} />,
 
@@ -467,6 +467,34 @@ describe('organization resource stream', () => {
   })
 })
 
+describe('owner-addressed effects on a legacy tab', () => {
+  const legacyTab: MothershipResource = { type: 'file', id: 'f', title: 'notes' }
+  const owner = { entityType: 'workspace' as const, entityId: 'ws' }
+
+  function applyOwnerEffect(op: 'upsert' | 'remove') {
+    const deps = makeStreamLoopDeps({ workspaceId: 'ws', resourcesRef: ref([legacyTab]) })
+    handleResourceEvent(
+      { deps } as StreamLoopContext,
+      {
+        ...removeEvent('file', 'f'),
+        payload: { op, effectId: `effect:${op}`, resource: { type: 'file', id: 'f', owner } },
+      } as ResourceEvent
+    )
+    const updater = (deps.setResources as ReturnType<typeof vi.fn>).mock.calls[0][0] as (
+      current: MothershipResource[]
+    ) => MothershipResource[]
+    return updater([legacyTab])
+  }
+
+  it('closes the tab when the removal names its workspace owner', () => {
+    expect(applyOwnerEffect('remove')).toEqual([])
+  })
+
+  it('updates the tab in place instead of opening a duplicate', () => {
+    expect(applyOwnerEffect('upsert')).toHaveLength(1)
+  })
+})
+
 it('seeds only fresh matching search effects and never seeds replayed or foreign evidence', () => {
   const deps = makeStreamLoopDeps({
     workspaceId: undefined,
 
@@ -8,7 +8,7 @@ import type { FilePreviewSession } from '@/lib/mothership/request/session'
 import type { PersistedStreamEventEnvelope } from '@/lib/mothership/request/session/contract'
 import { searchResourceMatchesOwner } from '@/lib/mothership/resources/search'
 import {
-  getChatResourceKey,
+  chatResourceKeyFor,
   getChatResourceSelectionId,
   mergeChatResource,
 } from '@/lib/mothership/resources/types'
@@ -102,6 +102,7 @@ export function handleResourceEvent(ctx: StreamLoopContext, parsed: ResourceEven
   } = ctx.deps
   const onResourceEvent = onResourceEventRef.current
   const payload = parsed.payload
+  const keyOf = chatResourceKeyFor(chatWorkspaceId)
   if (payload.op === 'upsert' && payload.readOnly) return
   if (payload.resource.type === 'settings') {
     const settings = payload.resource
@@ -135,9 +136,7 @@ export function handleResourceEvent(ctx: StreamLoopContext, parsed: ResourceEven
       search,
     }
     if (payload.op === 'remove') {
-      setResources((current) =>
-        current.filter((item) => getChatResourceKey(item) !== getChatResourceKey(resource))
-      )
+      setResources((current) => current.filter((item) => keyOf(item) !== keyOf(resource)))
       return
     }
     const scopeKey =
@@ -181,9 +180,7 @@ export function handleResourceEvent(ctx: StreamLoopContext, parsed: ResourceEven
     if (ctx.deps.citedSourcesEnabled) return
     if (payload.effectId)
       setResources((current) => {
-        const found = current.find(
-          (item) => getChatResourceKey(item) === getChatResourceKey(resource)
-        )
+        const found = current.find((item) => keyOf(item) === keyOf(resource))
         return found
           ? current.map((item) => (item === found ? mergeChatResource(item, resource) : item))
           : [...current, resource]
@@ -257,7 +254,7 @@ export function handleResourceEvent(ctx: StreamLoopContext, parsed: ResourceEven
     const resourceType = resource.type
     if (payload.effectId) {
       applyResourceEffect(ctx, (current) =>
-        current.filter((item) => getChatResourceKey(item) !== getChatResourceKey(resource))
+        current.filter((item) => keyOf(item) !== keyOf(resource))
       )
       ctx.deps.setActiveResourceId((current) =>
         current === getChatResourceSelectionId(resource) ? null : current
@@ -308,13 +305,11 @@ export function handleResourceEvent(ctx: StreamLoopContext, parsed: ResourceEven
         !shouldAutoActivatePreviewSession(previewForResource)))
   const wasAdded =
     shouldSuppressFileResourceActivation || payload.effectId
-      ? !resourcesRef.current.some((r) => getChatResourceKey(r) === getChatResourceKey(resource))
+      ? !resourcesRef.current.some((r) => keyOf(r) === keyOf(resource))
       : addResource(resourceUpdate)
   if (payload.effectId) {
     applyResourceEffect(ctx, (current) => {
-      const previous = current.find(
-        (item) => getChatResourceKey(item) === getChatResourceKey(resource)
-      )
+      const previous = current.find((item) => keyOf(item) === keyOf(resource))
       const next = {
         ...previous,
         ...resource,
@@ -326,9 +321,7 @@ export function handleResourceEvent(ctx: StreamLoopContext, parsed: ResourceEven
     })
   } else if (shouldSuppressFileResourceActivation && wasAdded) {
     setResources((current) =>
-      current.some((r) => getChatResourceKey(r) === getChatResourceKey(resource))
-        ? current
-        : [...current, resource]
+      current.some((r) => keyOf(r) === keyOf(resource)) ? current : [...current, resource]
     )
   }
   if (completedPreviewHandoff && isCompletedPreviewHandoffCurrent) {
@@ -341,14 +334,8 @@ export function handleResourceEvent(ctx: StreamLoopContext, parsed: ResourceEven
     // report "added", while only the first updater actually inserted — the
     // updater is idempotent, so it simply runs every time.
     setResources((current) =>
-      current.some(
-        (r) => getChatResourceKey(r) === getChatResourceKey(resource) && r.viewId !== pinnedViewId
-      )
-        ? current.map((r) =>
-            getChatResourceKey(r) === getChatResourceKey(resource)
-              ? { ...r, viewId: pinnedViewId }
-              : r
-          )
+      current.some((r) => keyOf(r) === keyOf(resource) && r.viewId !== pinnedViewId)
+        ? current.map((r) => (keyOf(r) === keyOf(resource) ? { ...r, viewId: pinnedViewId } : r))
         : current
     )
     // Consumed by the embedded table once its views list carries the view —