diff --git a/apps/sim/app/api/files/serve/[...path]/route.test.ts b/apps/sim/app/api/files/serve/[...path]/route.test.ts
index 495f4ad4913..799fb19b97c 100644
--- a/apps/sim/app/api/files/serve/[...path]/route.test.ts
+++ b/apps/sim/app/api/files/serve/[...path]/route.test.ts
@@ -20,6 +20,10 @@ const {
   mockIsUsingCloudStorage,
   mockDownloadCopilotFile,
   mockInferContextFromKey,
+  mockParseWorkspaceFileKey,
+  mockAuthenticateWorkspaceFile,
+  mockReadWorkspaceFileContentByKey,
+  mockResolveServableDocBytes,
   mockGetContentType,
   mockFindLocalFile,
   mockCreateFileResponse,
@@ -40,6 +44,10 @@ const {
     mockIsUsingCloudStorage: vi.fn(),
     mockDownloadCopilotFile: vi.fn(),
     mockInferContextFromKey: vi.fn(),
+    mockParseWorkspaceFileKey: vi.fn(),
+    mockAuthenticateWorkspaceFile: vi.fn(),
+    mockReadWorkspaceFileContentByKey: vi.fn(),
+    mockResolveServableDocBytes: vi.fn(),
     mockGetContentType: vi.fn(),
     mockFindLocalFile: vi.fn(),
     mockCreateFileResponse: vi.fn(),
@@ -82,7 +90,19 @@ vi.mock('@/lib/execution/sandbox/run-task', () => ({
 }))
 
 vi.mock('@/lib/uploads/contexts/workspace/workspace-file-manager', () => ({
-  parseWorkspaceFileKey: vi.fn().mockReturnValue(undefined),
+  parseWorkspaceFileKey: mockParseWorkspaceFileKey,
+}))
+
+vi.mock('@/lib/workspace-files/api', () => ({
+  internalWorkspaceFileServeAuth: { authenticate: mockAuthenticateWorkspaceFile },
+}))
+
+vi.mock('@/lib/workspace-files/application/read-workspace-file-content-by-key', () => ({
+  readWorkspaceFileContentByKey: { execute: mockReadWorkspaceFileContentByKey },
+}))
+
+vi.mock('@/lib/copilot/tools/server/files/doc-compile', () => ({
+  resolveServableDocBytes: mockResolveServableDocBytes,
 }))
 
 vi.mock('@/app/api/files/utils', () => ({
@@ -109,7 +129,27 @@ describe('File Serve API Route', () => {
     mockReadFile.mockResolvedValue(Buffer.from('test content'))
     mockIsUsingCloudStorage.mockReturnValue(false)
     storageServiceMockFns.mockHasCloudStorage.mockReturnValue(true)
-    mockInferContextFromKey.mockReturnValue('workspace')
+    mockInferContextFromKey.mockReturnValue('mothership')
+    mockParseWorkspaceFileKey.mockReturnValue(undefined)
+    mockAuthenticateWorkspaceFile.mockResolvedValue({
+      kind: 'session',
+      userId: 'test-user-id',
+      sessionId: 'session-1',
+    })
+    mockReadWorkspaceFileContentByKey.mockResolvedValue({
+      file: {
+        id: 'file-1',
+        workspaceId: 'test-workspace-id',
+        name: 'report.pdf',
+      },
+      content: Buffer.from('generated source'),
+    })
+    mockResolveServableDocBytes.mockImplementation(
+      async ({ rawBuffer, fileName }: { rawBuffer: Buffer; fileName: string }) => ({
+        buffer: rawBuffer,
+        contentType: mockGetContentType(fileName),
+      })
+    )
     mockGetContentType.mockReturnValue('text/plain')
     mockFindLocalFile.mockReturnValue('/test/uploads/test-file.txt')
     mockCreateFileResponse.mockImplementation(
@@ -181,8 +221,59 @@ describe('File Serve API Route', () => {
 
     expect(storageServiceMockFns.mockDownloadFile).toHaveBeenCalledWith({
       key: 'workspace/test-workspace-id/1234567890-image.png',
-      context: 'workspace',
+      context: 'mothership',
+    })
+  })
+
+  it('serves a workspace document through the authorized use case and preserves the Principal', async () => {
+    const principal = {
+      kind: 'delegated' as const,
+      serviceId: 'executor' as const,
+      subjectUserId: 'test-user-id',
+      workspaceId: 'test-workspace-id',
+      delegationId: 'delegation-1',
+      audience: 'sim:workspace-files',
+      issuedAt: new Date('2026-08-01T00:00:00Z'),
+      expiresAt: new Date('2026-08-01T01:00:00Z'),
+      delegationContext: {
+        kind: 'workflow_execution' as const,
+        workflowId: 'workflow-1',
+      },
+    }
+    mockInferContextFromKey.mockReturnValue('workspace')
+    mockParseWorkspaceFileKey.mockReturnValue('test-workspace-id')
+    mockAuthenticateWorkspaceFile.mockResolvedValue(principal)
+    mockResolveServableDocBytes.mockResolvedValue({
+      buffer: Buffer.from('%PDF-compiled'),
+      contentType: 'application/pdf',
     })
+
+    const req = new NextRequest(
+      'http://localhost:3000/api/files/serve/workspace/test-workspace-id/report.pdf'
+    )
+    const response = await GET(req, {
+      params: Promise.resolve({
+        path: ['workspace', 'test-workspace-id', 'report.pdf'],
+      }),
+    })
+
+    expect(response.status).toBe(200)
+    expect(mockReadWorkspaceFileContentByKey).toHaveBeenCalledWith({
+      principal,
+      input: {
+        key: 'workspace/test-workspace-id/report.pdf',
+        assertedWorkspaceId: 'test-workspace-id',
+      },
+      request: req,
+    })
+    expect(mockResolveServableDocBytes).toHaveBeenCalledWith(
+      expect.objectContaining({
+        workspaceId: 'test-workspace-id',
+        filePrincipal: principal,
+      })
+    )
+    expect(hybridAuthMockFns.mockCheckSessionOrInternalAuth).not.toHaveBeenCalled()
+    expect(mockVerifyFileAccess).not.toHaveBeenCalled()
   })
 
   it('should return 404 when file not found', async () => {
diff --git a/apps/sim/app/api/files/serve/[...path]/route.ts b/apps/sim/app/api/files/serve/[...path]/route.ts
index 7ba54de8e06..0899cdd0dfa 100644
--- a/apps/sim/app/api/files/serve/[...path]/route.ts
+++ b/apps/sim/app/api/files/serve/[...path]/route.ts
@@ -1,11 +1,17 @@
 import { readFile } from 'fs/promises'
+import { type Principal, requirePrincipalSubjectUserId } from '@sim/auth/principal'
 import { createLogger } from '@sim/logger'
 import type { NextRequest } from 'next/server'
 import { NextResponse } from 'next/server'
 import { fileServeParamsSchema, fileServeQuerySchema } from '@/lib/api/contracts/storage-transfer'
+import {
+  concealCrossTenantResourceError,
+  InternalUnauthenticatedError,
+} from '@/lib/api/server/routes'
 import { checkSessionOrInternalAuth } from '@/lib/auth/hybrid'
 import { resolveServableDocBytes } from '@/lib/copilot/tools/server/files/doc-compile'
 import { DocCompileUserError } from '@/lib/copilot/tools/server/files/doc-compile-error'
+import { asOrchestrationError } from '@/lib/core/orchestration/types'
 import { withRouteHandler } from '@/lib/core/utils/with-route-handler'
 import { CopilotFiles, isUsingCloudStorage } from '@/lib/uploads'
 import type { StorageContext } from '@/lib/uploads/config'
@@ -13,6 +19,8 @@ import { parseWorkspaceFileKey } from '@/lib/uploads/contexts/workspace/workspac
 import { downloadFile } from '@/lib/uploads/core/storage-service'
 import { resolveServableImageBytes } from '@/lib/uploads/server/image-derivative'
 import { inferContextFromKey } from '@/lib/uploads/utils/file-utils'
+import { internalWorkspaceFileServeAuth } from '@/lib/workspace-files/api'
+import { readWorkspaceFileContentByKey } from '@/lib/workspace-files/application/read-workspace-file-content-by-key'
 import { verifyFileAccess } from '@/app/api/files/authorization'
 import {
   createErrorResponse,
@@ -66,9 +74,11 @@ async function resolveServableBytes(params: {
   workspaceId: string | undefined
   options: ServeOptions
   ownerKey: string | undefined
+  filePrincipal?: Principal
   signal: AbortSignal | undefined
 }): Promise<{ buffer: Buffer; contentType: string }> {
-  const { buffer, filename, storageKey, workspaceId, options, ownerKey, signal } = params
+  const { buffer, filename, storageKey, workspaceId, options, ownerKey, filePrincipal, signal } =
+    params
   if (options.raw) return { buffer, contentType: getContentType(filename) }
 
   if (options.preview) {
@@ -82,6 +92,7 @@ async function resolveServableBytes(params: {
     rawBuffer: buffer,
     fileName: filename,
     workspaceId,
+    filePrincipal,
     ownerKey,
     signal,
   })
@@ -154,6 +165,23 @@ export const GET = withRouteHandler(
         return await handleLocalFilePublic(fullPath)
       }
 
+      const storageContext = inferContextFromKey(cloudKey)
+      const workspacePrincipal =
+        storageContext === 'workspace'
+          ? await internalWorkspaceFileServeAuth.authenticate(request, { path })
+          : undefined
+      const legacyAuthResult = workspacePrincipal
+        ? undefined
+        : await checkSessionOrInternalAuth(request, { requireWorkflowId: false })
+
+      if (legacyAuthResult && (!legacyAuthResult.success || !legacyAuthResult.userId)) {
+        logger.warn('Unauthorized file access attempt', {
+          path,
+          error: legacyAuthResult.error || 'Missing userId',
+        })
+        return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
+      }
+
       const query = fileServeQuerySchema.parse({
         raw: request.nextUrl.searchParams.get('raw'),
         preview: request.nextUrl.searchParams.get('preview'),
@@ -165,17 +193,12 @@ export const GET = withRouteHandler(
         versioned: query.v != null,
       }
 
-      const authResult = await checkSessionOrInternalAuth(request, { requireWorkflowId: false })
-
-      if (!authResult.success || !authResult.userId) {
-        logger.warn('Unauthorized file access attempt', {
-          path,
-          error: authResult.error || 'Missing userId',
-        })
-        return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
+      if (workspacePrincipal) {
+        return await handleWorkspaceFile(cloudKey, workspacePrincipal, options, request)
       }
 
-      const userId = authResult.userId
+      const userId = legacyAuthResult?.userId
+      if (!userId) throw new Error('Authenticated file serve request is missing a user ID')
 
       if (isUsingCloudStorage()) {
         return await handleCloudProxy(cloudKey, userId, options, request.signal)
@@ -183,6 +206,11 @@ export const GET = withRouteHandler(
 
       return await handleLocalFile(cloudKey, userId, options, request.signal)
     } catch (error) {
+      if (error instanceof InternalUnauthenticatedError) {
+        logger.warn('Unauthorized file access attempt', { error: error.message })
+        return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
+      }
+
       // An in-progress/incomplete doc source fails to compile — this is expected
       // mid-generation, not a server fault. Return 409 (not 500) so it isn't an
       // alarming error; the client re-fetches once the doc finishes (the serve
@@ -194,6 +222,15 @@ export const GET = withRouteHandler(
         return NextResponse.json({ error: 'Document is still being generated' }, { status: 409 })
       }
 
+      const orchestrationError = asOrchestrationError(
+        concealCrossTenantResourceError(error, 'File not found')
+      )
+      if (orchestrationError?.code === 'not_found') {
+        const notFound = new FileNotFoundError('File not found')
+        logServeFailure('Error serving file:', notFound)
+        return createErrorResponse(notFound)
+      }
+
       logServeFailure('Error serving file:', error)
 
       if (error instanceof FileNotFoundError) {
@@ -205,6 +242,45 @@ export const GET = withRouteHandler(
   }
 )
 
+async function handleWorkspaceFile(
+  key: string,
+  principal: Principal,
+  options: ServeOptions,
+  request: NextRequest
+): Promise<NextResponse> {
+  const workspaceId = getWorkspaceIdForCompile(key)
+  if (!workspaceId) throw new FileNotFoundError(`File not found: ${key}`)
+
+  const { file, content } = await readWorkspaceFileContentByKey.execute({
+    principal,
+    input: { key, assertedWorkspaceId: workspaceId },
+    request,
+  })
+  const ownerKey = `user:${requirePrincipalSubjectUserId(principal)}`
+  const resolved = await resolveServableBytes({
+    buffer: content,
+    filename: file.name,
+    storageKey: key,
+    workspaceId,
+    options,
+    ownerKey,
+    filePrincipal: principal,
+    signal: request.signal,
+  })
+
+  logger.info('Workspace file served', {
+    fileId: file.id,
+    workspaceId,
+    size: resolved.buffer.length,
+  })
+  return createFileResponse({
+    buffer: resolved.buffer,
+    contentType: resolved.contentType,
+    filename: file.name,
+    cacheControl: resolveServeCacheControl(options.versioned, 'workspace'),
+  })
+}
+
 async function handleLocalFile(
   filename: string,
   userId: string,
diff --git a/apps/sim/app/api/v1/auth.test.ts b/apps/sim/app/api/v1/auth.test.ts
new file mode 100644
index 00000000000..90f0f2f1d76
--- /dev/null
+++ b/apps/sim/app/api/v1/auth.test.ts
@@ -0,0 +1,86 @@
+/**
+ * @vitest-environment node
+ */
+
+import { NextRequest } from 'next/server'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+const mocks = vi.hoisted(() => ({
+  authenticateApiKey: vi.fn(),
+  updateLastUsed: vi.fn(),
+}))
+
+vi.mock('@/lib/core/config/env-flags', () => ({ isAuthDisabled: false }))
+vi.mock('@/lib/api-key/service', () => ({
+  authenticateApiKeyFromHeader: mocks.authenticateApiKey,
+  updateApiKeyLastUsed: mocks.updateLastUsed,
+}))
+
+import { authenticateV1Request } from '@/app/api/v1/auth'
+
+describe('v1 API key authentication', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  it('constructs a personal API-key Principal from canonical key identity', async () => {
+    mocks.authenticateApiKey.mockResolvedValue({
+      success: true,
+      userId: 'user-1',
+      keyId: 'key-1',
+      keyType: 'personal',
+    })
+
+    await expect(
+      authenticateV1Request(
+        new NextRequest('http://localhost/api/v1/files', {
+          headers: { 'x-api-key': 'secret' },
+        })
+      )
+    ).resolves.toMatchObject({
+      authenticated: true,
+      principal: { kind: 'personal_api_key', userId: 'user-1', keyId: 'key-1' },
+    })
+  })
+
+  it('constructs a workspace API-key Principal without borrowing the creator identity', async () => {
+    mocks.authenticateApiKey.mockResolvedValue({
+      success: true,
+      userId: 'creator-1',
+      keyId: 'key-1',
+      keyType: 'workspace',
+      workspaceId: 'workspace-1',
+    })
+
+    const result = await authenticateV1Request(
+      new NextRequest('http://localhost/api/v1/files', {
+        headers: { 'x-api-key': 'secret' },
+      })
+    )
+
+    expect(result.principal).toEqual({
+      kind: 'workspace_api_key',
+      workspaceId: 'workspace-1',
+      keyId: 'key-1',
+    })
+    expect(result.principal).not.toHaveProperty('userId')
+  })
+
+  it('fails closed when authenticated key identity is incomplete', async () => {
+    mocks.authenticateApiKey.mockResolvedValue({
+      success: true,
+      userId: 'creator-1',
+      keyId: 'key-1',
+      keyType: 'workspace',
+    })
+
+    await expect(
+      authenticateV1Request(
+        new NextRequest('http://localhost/api/v1/files', {
+          headers: { 'x-api-key': 'secret' },
+        })
+      )
+    ).resolves.toEqual({ authenticated: false, error: 'Authentication failed' })
+    expect(mocks.updateLastUsed).not.toHaveBeenCalled()
+  })
+})
diff --git a/apps/sim/app/api/v1/auth.ts b/apps/sim/app/api/v1/auth.ts
index 0f391889005..78c68e1f9dd 100644
--- a/apps/sim/app/api/v1/auth.ts
+++ b/apps/sim/app/api/v1/auth.ts
@@ -1,3 +1,4 @@
+import type { PersonalApiKeyPrincipal, WorkspaceApiKeyPrincipal } from '@sim/auth/principal'
 import { createLogger } from '@sim/logger'
 import type { NextRequest } from 'next/server'
 import { authenticateApiKeyFromHeader, updateApiKeyLastUsed } from '@/lib/api-key/service'
@@ -11,6 +12,7 @@ export interface AuthResult {
   userId?: string
   workspaceId?: string
   keyType?: 'personal' | 'workspace'
+  principal?: PersonalApiKeyPrincipal | WorkspaceApiKeyPrincipal
   error?: string
 }
 
@@ -20,6 +22,11 @@ export async function authenticateV1Request(request: NextRequest): Promise<AuthR
       authenticated: true,
       userId: ANONYMOUS_USER_ID,
       keyType: 'personal',
+      principal: {
+        kind: 'personal_api_key',
+        userId: ANONYMOUS_USER_ID,
+        keyId: 'auth-disabled',
+      },
     }
   }
 
@@ -43,13 +50,35 @@ export async function authenticateV1Request(request: NextRequest): Promise<AuthR
       }
     }
 
-    await updateApiKeyLastUsed(result.keyId!)
+    if (!result.keyId || !result.userId || !result.keyType) {
+      throw new Error('Authenticated v1 API key is missing its canonical identity')
+    }
+    let principal: PersonalApiKeyPrincipal | WorkspaceApiKeyPrincipal
+    if (result.keyType === 'workspace') {
+      if (!result.workspaceId) {
+        throw new Error('Authenticated workspace API key is missing its workspace scope')
+      }
+      principal = {
+        kind: 'workspace_api_key',
+        workspaceId: result.workspaceId,
+        keyId: result.keyId,
+      }
+    } else {
+      principal = {
+        kind: 'personal_api_key',
+        userId: result.userId,
+        keyId: result.keyId,
+      }
+    }
+
+    await updateApiKeyLastUsed(result.keyId)
 
     return {
       authenticated: true,
-      userId: result.userId!,
+      userId: result.userId,
       workspaceId: result.workspaceId,
       keyType: result.keyType,
+      principal,
     }
   } catch (error) {
     logger.error('API key authentication error', { error })
diff --git a/apps/sim/app/api/v1/files/[fileId]/route.test.ts b/apps/sim/app/api/v1/files/[fileId]/route.test.ts
index 8e4927490e3..7c54b478104 100644
--- a/apps/sim/app/api/v1/files/[fileId]/route.test.ts
+++ b/apps/sim/app/api/v1/files/[fileId]/route.test.ts
@@ -8,24 +8,27 @@ const {
   mockCheckRateLimit,
   mockValidateWorkspaceAccess,
   mockGetWorkspaceFile,
-  mockFetchServableWorkspaceFileBuffer,
+  mockDownloadWorkspaceFileStream,
 } = vi.hoisted(() => ({
   mockCheckRateLimit: vi.fn(),
   mockValidateWorkspaceAccess: vi.fn(),
   mockGetWorkspaceFile: vi.fn(),
-  mockFetchServableWorkspaceFileBuffer: vi.fn(),
+  mockDownloadWorkspaceFileStream: vi.fn(),
 }))
 
 vi.mock('@/app/api/v1/middleware', () => ({
   checkRateLimit: mockCheckRateLimit,
   createRateLimitResponse: () => new Response('rate limited', { status: 429 }),
+  requireRateLimitPrincipal: (rateLimit: { principal: unknown }) => rateLimit.principal,
   validateWorkspaceAccess: mockValidateWorkspaceAccess,
   v1ValidationErrorResponse: (e: { issues: unknown[] }) =>
     NextResponse.json({ error: 'Validation error', details: e.issues }, { status: 400 }),
 }))
 vi.mock('@/lib/uploads/contexts/workspace', () => ({
   getWorkspaceFile: mockGetWorkspaceFile,
-  fetchServableWorkspaceFileBuffer: mockFetchServableWorkspaceFileBuffer,
+}))
+vi.mock('@/lib/workspace-files/application/download-workspace-file', () => ({
+  downloadWorkspaceFileStream: { execute: mockDownloadWorkspaceFileStream },
 }))
 vi.mock('@/lib/workspace-files/orchestration', () => ({
   performDeleteWorkspaceFileItems: vi.fn(),
@@ -37,7 +40,7 @@ vi.mock('@sim/audit', () => ({
 }))
 vi.mock('@/lib/posthog/server', () => ({ captureServerEvent: vi.fn() }))
 
-import { DocCompileUserError } from '@/lib/copilot/tools/server/files/doc-compile-error'
+import { OrchestrationError } from '@/lib/core/orchestration/types'
 import { GET } from '@/app/api/v1/files/[fileId]/route'
 
 const WORKSPACE_ID = 'ws-1'
@@ -45,6 +48,11 @@ const FILE_ID = 'file-1'
 const context = { params: Promise.resolve({ fileId: FILE_ID }) }
 
 const DOCX_MIME = 'application/vnd.openxmlformats-officedocument.wordprocessingml.document'
+const PRINCIPAL = {
+  kind: 'personal_api_key' as const,
+  userId: 'user-1',
+  keyId: 'key-1',
+}
 
 function request() {
   return createMockRequest(
@@ -71,16 +79,31 @@ function generatedDocument(name = 'report.docx') {
   }
 }
 
+function renderedDownload(buffer: Buffer) {
+  return {
+    file: generatedDocument(),
+    stream: new ReadableStream<Uint8Array>({
+      start(controller) {
+        controller.enqueue(buffer)
+        controller.close()
+      },
+    }),
+    contentLength: buffer.length,
+    contentType: DOCX_MIME,
+  }
+}
+
 describe('v1 file download', () => {
   beforeEach(() => {
     vi.clearAllMocks()
-    mockCheckRateLimit.mockResolvedValue({ allowed: true, userId: 'user-1' })
+    mockCheckRateLimit.mockResolvedValue({
+      allowed: true,
+      userId: 'user-1',
+      principal: PRINCIPAL,
+    })
     mockValidateWorkspaceAccess.mockResolvedValue(null)
     mockGetWorkspaceFile.mockResolvedValue(generatedDocument())
-    mockFetchServableWorkspaceFileBuffer.mockResolvedValue({
-      buffer: Buffer.from('PKrendered'),
-      contentType: DOCX_MIME,
-    })
+    mockDownloadWorkspaceFileStream.mockResolvedValue(renderedDownload(Buffer.from('PKrendered')))
   })
 
   it('serves the rendered bytes and the rendered content type', async () => {
@@ -104,10 +127,7 @@ describe('v1 file download', () => {
 
   it('reports Content-Length from the rendered bytes, not the declared source size', async () => {
     const rendered = Buffer.alloc(50_000)
-    mockFetchServableWorkspaceFileBuffer.mockResolvedValue({
-      buffer: rendered,
-      contentType: DOCX_MIME,
-    })
+    mockDownloadWorkspaceFileStream.mockResolvedValue(renderedDownload(rendered))
 
     const response = await GET(request(), context)
 
@@ -115,8 +135,8 @@ describe('v1 file download', () => {
   })
 
   it('returns a retryable 409 while the artifact is still compiling', async () => {
-    mockFetchServableWorkspaceFileBuffer.mockRejectedValue(
-      new DocCompileUserError('Document is still being generated')
+    mockDownloadWorkspaceFileStream.mockRejectedValue(
+      new OrchestrationError('conflict', 'Document is still being generated')
     )
 
     const response = await GET(request(), context)
@@ -127,11 +147,17 @@ describe('v1 file download', () => {
   })
 
   it('404s a file that does not exist', async () => {
-    mockGetWorkspaceFile.mockResolvedValue(null)
+    mockDownloadWorkspaceFileStream.mockRejectedValue(
+      new OrchestrationError('not_found', 'File not found')
+    )
 
     const response = await GET(request(), context)
 
     expect(response.status).toBe(404)
-    expect(mockFetchServableWorkspaceFileBuffer).not.toHaveBeenCalled()
+    expect(mockDownloadWorkspaceFileStream).toHaveBeenCalledWith({
+      principal: PRINCIPAL,
+      input: { fileId: FILE_ID, assertedWorkspaceId: WORKSPACE_ID },
+      request: expect.anything(),
+    })
   })
 })
diff --git a/apps/sim/app/api/v1/files/[fileId]/route.ts b/apps/sim/app/api/v1/files/[fileId]/route.ts
index 1e9b084e680..eb767ac5f3c 100644
--- a/apps/sim/app/api/v1/files/[fileId]/route.ts
+++ b/apps/sim/app/api/v1/files/[fileId]/route.ts
@@ -1,20 +1,18 @@
-import { AuditAction, AuditResourceType, recordAudit } from '@sim/audit'
 import { createLogger } from '@sim/logger'
 import { type NextRequest, NextResponse } from 'next/server'
 import { v1DeleteFileContract, v1DownloadFileContract } from '@/lib/api/contracts/v1/files'
 import { parseRequest } from '@/lib/api/server'
+import { asOrchestrationError, statusForOrchestrationError } from '@/lib/core/orchestration/types'
 import { generateRequestId } from '@/lib/core/utils/request'
 import { withRouteHandler } from '@/lib/core/utils/with-route-handler'
 import { captureServerEvent } from '@/lib/posthog/server'
-import {
-  fetchServableWorkspaceFileBuffer,
-  getWorkspaceFile,
-} from '@/lib/uploads/contexts/workspace'
-import { docNotReadyMessage, isDocNotReadyError } from '@/lib/uploads/utils/doc-not-ready'
+import { getWorkspaceFile } from '@/lib/uploads/contexts/workspace'
+import { downloadWorkspaceFileStream } from '@/lib/workspace-files/application/download-workspace-file'
 import { performDeleteWorkspaceFileItems } from '@/lib/workspace-files/orchestration'
 import {
   checkRateLimit,
   createRateLimitResponse,
+  requireRateLimitPrincipal,
   v1ValidationErrorResponse,
   validateWorkspaceAccess,
 } from '@/app/api/v1/middleware'
@@ -38,7 +36,6 @@ export const GET = withRouteHandler(async (request: NextRequest, context: FileRo
       return createRateLimitResponse(rateLimit)
     }
 
-    const userId = rateLimit.userId!
     const parsed = await parseRequest(v1DownloadFileContract, request, context, {
       validationErrorResponse: v1ValidationErrorResponse,
     })
@@ -47,64 +44,43 @@ export const GET = withRouteHandler(async (request: NextRequest, context: FileRo
     const { fileId } = parsed.data.params
     const { workspaceId } = parsed.data.query
 
-    const accessError = await validateWorkspaceAccess(rateLimit, userId, workspaceId)
-    if (accessError) return accessError
-
-    const fileRecord = await getWorkspaceFile(workspaceId, fileId)
-    if (!fileRecord) {
-      return NextResponse.json({ error: 'File not found' }, { status: 404 })
+    const principal = requireRateLimitPrincipal(rateLimit)
+    const { file, stream, contentLength, contentType } = await downloadWorkspaceFileStream.execute({
+      principal,
+      input: { fileId, assertedWorkspaceId: workspaceId },
+      request,
+    })
+    if (principal.kind === 'personal_api_key') {
+      captureServerEvent(
+        principal.userId,
+        'file_downloaded',
+        { workspace_id: workspaceId, is_bulk: false, file_count: 1 },
+        { groups: { workspace: workspaceId } }
+      )
     }
 
-    // Generated docs store their generation source; serve the rendered artifact.
-    // Its content type is the rendered one, not the source MIME on the record.
-    const { buffer, contentType } = await fetchServableWorkspaceFileBuffer(fileRecord)
-
-    recordAudit({
-      workspaceId,
-      actorId: userId,
-      action: AuditAction.FILE_DOWNLOADED,
-      resourceType: AuditResourceType.FILE,
-      resourceId: fileRecord.id,
-      resourceName: fileRecord.name,
-      description: `Downloaded file "${fileRecord.name}" via API`,
-      metadata: {
-        fileId: fileRecord.id,
-        fileName: fileRecord.name,
-        bytes: buffer.length,
-        source: 'api_v1',
+    return new Response(stream, {
+      status: 200,
+      headers: {
+        'Content-Type': contentType || file.type || 'application/octet-stream',
+        'Content-Disposition': `attachment; filename="${file.name.replace(/[^\w.-]/g, '_')}"; filename*=UTF-8''${encodeURIComponent(file.name)}`,
+        'Content-Length': String(contentLength),
+        'X-File-Id': file.id,
+        'X-File-Name': encodeURIComponent(file.name),
+        'X-Uploaded-At':
+          file.uploadedAt instanceof Date ? file.uploadedAt.toISOString() : String(file.uploadedAt),
       },
-      request,
     })
-    captureServerEvent(
-      userId,
-      'file_downloaded',
-      { workspace_id: workspaceId, is_bulk: false, file_count: 1 },
-      { groups: { workspace: workspaceId } }
-    )
-
-    // View, not copy — a second full copy would double peak memory for a large file.
-    return new Response(
-      new Uint8Array(buffer.buffer as ArrayBuffer, buffer.byteOffset, buffer.byteLength),
-      {
-        status: 200,
-        headers: {
-          'Content-Type': contentType || fileRecord.type || 'application/octet-stream',
-          'Content-Disposition': `attachment; filename="${fileRecord.name.replace(/[^\w.-]/g, '_')}"; filename*=UTF-8''${encodeURIComponent(fileRecord.name)}`,
-          'Content-Length': String(buffer.length),
-          'X-File-Id': fileRecord.id,
-          'X-File-Name': encodeURIComponent(fileRecord.name),
-          'X-Uploaded-At':
-            fileRecord.uploadedAt instanceof Date
-              ? fileRecord.uploadedAt.toISOString()
-              : String(fileRecord.uploadedAt),
-        },
-      }
-    )
   } catch (error) {
-    // A generated doc whose artifact is still compiling is retryable, not a fault:
-    // without this the caller sees a 500 and has no reason to try again.
-    if (isDocNotReadyError(error)) {
-      return NextResponse.json({ error: docNotReadyMessage() }, { status: 409 })
+    const orchestrationError = asOrchestrationError(error)
+    if (orchestrationError && orchestrationError.code !== 'internal') {
+      return NextResponse.json(
+        {
+          error:
+            orchestrationError.code === 'not_found' ? 'File not found' : orchestrationError.message,
+        },
+        { status: statusForOrchestrationError(orchestrationError.code) }
+      )
     }
     logger.error(`[${requestId}] Error downloading file:`, error)
     return NextResponse.json({ error: 'Failed to download file' }, { status: 500 })
diff --git a/apps/sim/app/api/v1/middleware.test.ts b/apps/sim/app/api/v1/middleware.test.ts
index 94c0790b274..2a8e598a7b6 100644
--- a/apps/sim/app/api/v1/middleware.test.ts
+++ b/apps/sim/app/api/v1/middleware.test.ts
@@ -61,6 +61,7 @@ describe('checkRateLimit', () => {
       authenticated: true,
       userId: 'user-1',
       keyType: 'personal',
+      principal: { kind: 'personal_api_key', userId: 'user-1', keyId: 'key-1' },
     })
     mockGetSubscription.mockResolvedValue({ plan: 'team' })
     mockGetRateLimit.mockReturnValue(TEAM_BUCKET)
@@ -78,6 +79,16 @@ describe('checkRateLimit', () => {
     expect(result.limit).not.toBe(TEAM_BUCKET.refillRate)
   })
 
+  it('preserves the authenticated API-key Principal for application operations', async () => {
+    const result = await checkRateLimit(request(), 'workflows')
+
+    expect(result.principal).toEqual({
+      kind: 'personal_api_key',
+      userId: 'user-1',
+      keyId: 'key-1',
+    })
+  })
+
   it('never reports more remaining than the limit', async () => {
     const result = await checkRateLimit(request(), 'workflows')
 
@@ -196,6 +207,7 @@ describe('rate-limit snapshot context', () => {
       authenticated: true,
       userId: 'user-1',
       keyType: 'personal',
+      principal: { kind: 'personal_api_key', userId: 'user-1', keyId: 'key-1' },
     })
     mockGetSubscription.mockResolvedValue({ plan: 'team' })
     mockGetRateLimit.mockReturnValue(TEAM_BUCKET)
diff --git a/apps/sim/app/api/v1/middleware.ts b/apps/sim/app/api/v1/middleware.ts
index 6a9db50ec44..3f8d4878119 100644
--- a/apps/sim/app/api/v1/middleware.ts
+++ b/apps/sim/app/api/v1/middleware.ts
@@ -1,3 +1,4 @@
+import type { PersonalApiKeyPrincipal, WorkspaceApiKeyPrincipal } from '@sim/auth/principal'
 import { createLogger } from '@sim/logger'
 import { type PermissionType, permissionSatisfies } from '@sim/platform-authz/workspace'
 import { type NextRequest, NextResponse } from 'next/server'
@@ -63,6 +64,7 @@ export interface RateLimitResult {
   userId?: string
   workspaceId?: string
   keyType?: 'personal' | 'workspace'
+  principal?: PersonalApiKeyPrincipal | WorkspaceApiKeyPrincipal
   error?: string
 }
 
@@ -82,6 +84,18 @@ export function requireRateLimitUserId(rateLimit: RateLimitResult): string {
   return rateLimit.userId
 }
 
+export function requireRateLimitPrincipal(
+  rateLimit: RateLimitResult
+): PersonalApiKeyPrincipal | WorkspaceApiKeyPrincipal {
+  if (!rateLimit.allowed) {
+    throw new Error('Cannot authorize a denied public API request')
+  }
+  if (!rateLimit.principal) {
+    throw new Error('Allowed public API request is missing its Principal')
+  }
+  return rateLimit.principal
+}
+
 export async function checkRateLimit(
   request: NextRequest,
   endpoint: ApiEndpoint = 'logs'
@@ -144,6 +158,7 @@ export async function checkRateLimit(
       userId,
       workspaceId: auth.workspaceId,
       keyType: auth.keyType,
+      principal: auth.principal,
     }
   } catch (error) {
     logger.error('Rate limit check error', { error })
diff --git a/apps/sim/lib/copilot/tools/handlers/function-execute.test.ts b/apps/sim/lib/copilot/tools/handlers/function-execute.test.ts
index 0717900344a..7501d3355ba 100644
--- a/apps/sim/lib/copilot/tools/handlers/function-execute.test.ts
+++ b/apps/sim/lib/copilot/tools/handlers/function-execute.test.ts
@@ -84,12 +84,14 @@ vi.mock('@/lib/uploads/core/storage-service', () => ({
 }))
 vi.mock('@/tools', () => ({ executeTool: mockExecuteTool }))
 vi.mock('@/lib/uploads/contexts/workspace/workspace-file-manager', () => ({
-  fetchServableWorkspaceFileBuffer: mockFetchServableWorkspaceFileBuffer,
   fetchWorkspaceFileBuffer: mockFetchWorkspaceFileBuffer,
   findWorkspaceFileRecord: mockFindWorkspaceFileRecord,
   getSandboxWorkspaceFilePath: mockGetSandboxWorkspaceFilePath,
   listWorkspaceFiles: mockListWorkspaceFiles,
 }))
+vi.mock('@/lib/workspace-files/application/fetch-servable-workspace-file-buffer', () => ({
+  fetchAuthorizedServableWorkspaceFileBuffer: mockFetchServableWorkspaceFileBuffer,
+}))
 vi.mock('@/lib/uploads/contexts/workspace/workspace-file-folder-manager', () => ({
   listWorkspaceFileFolders: mockListWorkspaceFileFolders,
 }))
diff --git a/apps/sim/lib/copilot/tools/handlers/function-execute.ts b/apps/sim/lib/copilot/tools/handlers/function-execute.ts
index 01773a65f00..a10c8365d27 100644
--- a/apps/sim/lib/copilot/tools/handlers/function-execute.ts
+++ b/apps/sim/lib/copilot/tools/handlers/function-execute.ts
@@ -30,7 +30,6 @@ import { queryRows } from '@/lib/table/rows/service'
 import { getTableById, listTables } from '@/lib/table/service'
 import { getOrCreateTableSnapshot, SNAPSHOT_MAX_BYTES } from '@/lib/table/snapshot-cache'
 import {
-  fetchServableWorkspaceFileBuffer,
   findWorkspaceFileRecord,
   getSandboxWorkspaceFilePath,
   type WorkspaceFileRecord,
@@ -42,6 +41,7 @@ import {
   hasCloudStorage,
 } from '@/lib/uploads/core/storage-service'
 import { isGeneratedDocumentSourceType } from '@/lib/uploads/utils/file-utils'
+import { fetchAuthorizedServableWorkspaceFileBuffer } from '@/lib/workspace-files/application/fetch-servable-workspace-file-buffer'
 import { listAllWorkspaceFiles } from '@/lib/workspace-files/application/list-workspace-files'
 import { readWorkspaceFileContent } from '@/lib/workspace-files/application/read-workspace-file-content'
 import { downloadWorkspaceFileRecord } from '@/lib/workspace-files/application/read-workspace-file-record'
@@ -202,7 +202,7 @@ async function pushWorkspaceFileMount(
   }
 
   const { buffer, contentType } = rendersFromSource
-    ? await fetchServableWorkspaceFileBuffer(record, {
+    ? await fetchAuthorizedServableWorkspaceFileBuffer(record, principal, {
         maxBytes: Math.min(MAX_FILE_SIZE, remainingBudget),
       }).catch((error) => {
         if (!isPayloadSizeLimitError(error)) throw error
diff --git a/apps/sim/lib/copilot/tools/server/files/doc-compile.test.ts b/apps/sim/lib/copilot/tools/server/files/doc-compile.test.ts
index 7e79ab14de6..734761a5c02 100644
--- a/apps/sim/lib/copilot/tools/server/files/doc-compile.test.ts
+++ b/apps/sim/lib/copilot/tools/server/files/doc-compile.test.ts
@@ -8,6 +8,7 @@ const {
   executeInSandboxMock,
   executeShellInSandboxMock,
   loadCompiledDocMock,
+  publishCompiledDocArtifactMock,
   readWorkspaceFileContentMock,
   readWorkspaceFileMetadataMock,
   storeCompiledDocMock,
@@ -15,6 +16,7 @@ const {
   executeInSandboxMock: vi.fn(),
   executeShellInSandboxMock: vi.fn(),
   loadCompiledDocMock: vi.fn(),
+  publishCompiledDocArtifactMock: vi.fn(),
   readWorkspaceFileContentMock: vi.fn(),
   readWorkspaceFileMetadataMock: vi.fn(),
   storeCompiledDocMock: vi.fn(),
@@ -35,6 +37,8 @@ vi.mock('@/lib/workspace-files/application/read-workspace-file-metadata', () =>
 }))
 vi.mock('./doc-compiled-store', () => ({
   loadCompiledDoc: loadCompiledDocMock,
+  loadPublishedCompiledDoc: vi.fn(),
+  publishCompiledDocArtifact: publishCompiledDocArtifactMock,
   storeCompiledDoc: storeCompiledDocMock,
 }))
 
@@ -245,5 +249,11 @@ describe('collectReferencedFileIds', () => {
     )
     expect(readWorkspaceFileContentMock).not.toHaveBeenCalled()
     expect(executeInSandboxMock).not.toHaveBeenCalled()
+    expect(publishCompiledDocArtifactMock).toHaveBeenCalledWith(
+      'workspace-1',
+      `image = await getFileBase64('${ID}')`,
+      'pdf',
+      expect.stringContaining(ID)
+    )
   })
 })
diff --git a/apps/sim/lib/copilot/tools/server/files/doc-compile.ts b/apps/sim/lib/copilot/tools/server/files/doc-compile.ts
index cb5c3f25a64..b6dafb6826b 100644
--- a/apps/sim/lib/copilot/tools/server/files/doc-compile.ts
+++ b/apps/sim/lib/copilot/tools/server/files/doc-compile.ts
@@ -2,6 +2,12 @@ import type { Principal } from '@sim/auth/principal'
 import { createLogger } from '@sim/logger'
 import { sha256Hex } from '@sim/security/hash'
 import { DocCompileUserError } from '@/lib/copilot/tools/server/files/doc-compile-error'
+import {
+  loadCompiledDoc,
+  loadPublishedCompiledDoc,
+  publishCompiledDocArtifact,
+  storeCompiledDoc,
+} from '@/lib/copilot/tools/server/files/doc-compiled-store'
 import { isDocSandboxEnabled } from '@/lib/core/config/env-flags'
 import { CodeLanguage } from '@/lib/execution/languages'
 import {
@@ -15,7 +21,6 @@ import { readWorkspaceFileContent } from '@/lib/workspace-files/application/read
 import { readWorkspaceFileMetadata } from '@/lib/workspace-files/application/read-workspace-file-metadata'
 import { getContentType } from '@/app/api/files/utils'
 import type { SandboxTaskId } from '@/sandbox-tasks/registry'
-import { loadCompiledDoc, storeCompiledDoc } from './doc-compiled-store'
 
 const logger = createLogger('CopilotDocCompile')
 
@@ -567,6 +572,14 @@ export async function compileDoc(args: CompileArgs): Promise<CompiledDocResult>
     referencedImages.artifactIdentity
   )
   if (existing) {
+    if (referencedImages.artifactIdentity) {
+      await publishCompiledDocArtifact(
+        workspaceId,
+        source,
+        fmt.ext,
+        referencedImages.artifactIdentity
+      )
+    }
     const contributingFiles = referencedImageIdentities(referencedImages)
     return {
       buffer: existing,
@@ -588,6 +601,7 @@ export async function loadCompiledDocByExt(
   ext: string,
   options: {
     allowLegacyReferencedArtifact?: boolean
+    allowPublishedReferencedArtifact?: boolean
     filePrincipal?: Principal
   } = {}
 ): Promise<{ buffer: Buffer; contentType: string } | null> {
@@ -599,6 +613,10 @@ export async function loadCompiledDocByExt(
       const buffer = await loadCompiledDoc(workspaceId, source, fmt.ext)
       return buffer ? { buffer, contentType: fmt.contentType } : null
     }
+    if (options.allowPublishedReferencedArtifact) {
+      const publishedBuffer = await loadPublishedCompiledDoc(workspaceId, source, fmt.ext)
+      if (publishedBuffer) return { buffer: publishedBuffer, contentType: fmt.contentType }
+    }
     if (!options.allowLegacyReferencedArtifact) return null
     const legacyBuffer = await loadCompiledDoc(workspaceId, source, fmt.ext)
     return legacyBuffer ? { buffer: legacyBuffer, contentType: fmt.contentType } : null
@@ -655,7 +673,7 @@ export async function resolveServableDoc(
       workspaceId,
       storedBytes.toString('utf-8'),
       fmt.ext,
-      { allowLegacyReferencedArtifact: true }
+      { allowLegacyReferencedArtifact: true, allowPublishedReferencedArtifact: true }
     )
     return artifact ? { kind: 'artifact', ...artifact } : { kind: 'unavailable' }
   } catch (error) {
@@ -743,7 +761,16 @@ export async function resolveServableDocBytes(args: {
       return compileDocInLegacySandbox({ source, fileName, workspaceId, ownerKey, signal }, fmt)
     }
     const referencedFileIds = collectReferencedFileIds(source)
-    if (referencedFileIds.size > 0 && filePrincipal) {
+    if (referencedFileIds.size > 0) {
+      if (!filePrincipal) {
+        const published = await loadCompiledDocByExt(workspaceId, source, extNoDot, {
+          allowPublishedReferencedArtifact: true,
+        })
+        if (published) return published
+        throw new Error(
+          'Referenced document resolution requires an authorized workspace file principal'
+        )
+      }
       return compileDoc({ source, fileName, workspaceId, filePrincipal, ownerKey, signal })
     }
     const stored = await loadCompiledDocByExt(workspaceId, source, extNoDot, {
diff --git a/apps/sim/lib/copilot/tools/server/files/doc-compiled-store.test.ts b/apps/sim/lib/copilot/tools/server/files/doc-compiled-store.test.ts
new file mode 100644
index 00000000000..3c9a6e6d3ab
--- /dev/null
+++ b/apps/sim/lib/copilot/tools/server/files/doc-compiled-store.test.ts
@@ -0,0 +1,78 @@
+/**
+ * @vitest-environment node
+ */
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+const { mockDownloadFile, mockHeadObject, mockUploadFile } = vi.hoisted(() => ({
+  mockDownloadFile: vi.fn(),
+  mockHeadObject: vi.fn(),
+  mockUploadFile: vi.fn(),
+}))
+
+vi.mock('@/lib/uploads/core/storage-service', () => ({
+  downloadFile: mockDownloadFile,
+  headObject: mockHeadObject,
+  uploadFile: mockUploadFile,
+}))
+
+import {
+  loadPublishedCompiledDoc,
+  storeCompiledDoc,
+} from '@/lib/copilot/tools/server/files/doc-compiled-store'
+
+describe('compiled document publication', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mockHeadObject.mockResolvedValue(null)
+  })
+
+  it('publishes a source-keyed pointer after storing a dependency-bound artifact', async () => {
+    await storeCompiledDoc(
+      'workspace-1',
+      'source',
+      'pdf',
+      'application/pdf',
+      Buffer.from('%PDF-artifact'),
+      'dependency-identity'
+    )
+
+    expect(mockUploadFile).toHaveBeenCalledTimes(2)
+    expect(mockUploadFile).toHaveBeenNthCalledWith(
+      2,
+      expect.objectContaining({
+        file: Buffer.from(
+          JSON.stringify({ version: 1, referencedInputIdentity: 'dependency-identity' })
+        ),
+        contentType: 'application/json',
+        context: 'copilot',
+        preserveKey: true,
+      })
+    )
+  })
+
+  it('loads only the exact dependency-bound artifact named by the published pointer', async () => {
+    mockHeadObject.mockResolvedValue({ size: 1 })
+    mockDownloadFile
+      .mockResolvedValueOnce(
+        Buffer.from(JSON.stringify({ version: 1, referencedInputIdentity: 'dependency-identity' }))
+      )
+      .mockResolvedValueOnce(Buffer.from('%PDF-artifact'))
+
+    await expect(loadPublishedCompiledDoc('workspace-1', 'source', 'pdf')).resolves.toEqual(
+      Buffer.from('%PDF-artifact')
+    )
+    expect(mockDownloadFile).toHaveBeenCalledTimes(2)
+    expect(mockDownloadFile.mock.calls[1]?.[0]).toEqual(
+      expect.objectContaining({ context: 'copilot' })
+    )
+  })
+
+  it('fails fast on a malformed published pointer', async () => {
+    mockHeadObject.mockResolvedValue({ size: 1 })
+    mockDownloadFile.mockResolvedValueOnce(Buffer.from('{not-json'))
+
+    await expect(loadPublishedCompiledDoc('workspace-1', 'source', 'pdf')).rejects.toThrow(
+      'Published compiled document pointer is malformed'
+    )
+  })
+})
diff --git a/apps/sim/lib/copilot/tools/server/files/doc-compiled-store.ts b/apps/sim/lib/copilot/tools/server/files/doc-compiled-store.ts
index b25921868a5..dc57f549f0b 100644
--- a/apps/sim/lib/copilot/tools/server/files/doc-compiled-store.ts
+++ b/apps/sim/lib/copilot/tools/server/files/doc-compiled-store.ts
@@ -1,7 +1,7 @@
 import { createHash } from 'node:crypto'
 import { createLogger } from '@sim/logger'
 import { getErrorMessage, toError } from '@sim/utils/errors'
-import { downloadFile, uploadFile } from '@/lib/uploads/core/storage-service'
+import { downloadFile, headObject, uploadFile } from '@/lib/uploads/core/storage-service'
 
 const logger = createLogger('CopilotDocCompiledStore')
 
@@ -30,6 +30,41 @@ function compiledArtifactKey(
   return `copilot-doc-compiled/${workspaceId}/${hash}.${ext}`
 }
 
+function publishedArtifactPointerKey(workspaceId: string, source: string, ext: string): string {
+  const sourceHash = createHash('sha256').update(source, 'utf-8').digest('hex')
+  return `copilot-doc-compiled/${workspaceId}/${sourceHash}.${ext}.published.json`
+}
+
+interface PublishedArtifactPointer {
+  version: 1
+  referencedInputIdentity: string
+}
+
+async function loadPublishedArtifactPointer(key: string): Promise<PublishedArtifactPointer | null> {
+  const stored = await headObject(key, 'copilot')
+  if (!stored) return null
+  const encoded = await downloadFile({ key, context: 'copilot' })
+
+  let decoded: unknown
+  try {
+    decoded = JSON.parse(encoded.toString('utf-8'))
+  } catch {
+    throw new Error(`Published compiled document pointer is malformed: ${key}`)
+  }
+  if (
+    typeof decoded !== 'object' ||
+    decoded === null ||
+    !('version' in decoded) ||
+    decoded.version !== 1 ||
+    !('referencedInputIdentity' in decoded) ||
+    typeof decoded.referencedInputIdentity !== 'string' ||
+    !decoded.referencedInputIdentity
+  ) {
+    throw new Error(`Published compiled document pointer is invalid: ${key}`)
+  }
+  return { version: 1, referencedInputIdentity: decoded.referencedInputIdentity }
+}
+
 /** Loads the compiled binary for the current source, or null if not yet built. */
 export async function loadCompiledDoc(
   workspaceId: string,
@@ -45,6 +80,56 @@ export async function loadCompiledDoc(
   }
 }
 
+/**
+ * Publishes the exact dependency-bound artifact that was produced under an authorized Principal.
+ * Public shares consume this pointer without gaining authority to read the referenced workspace
+ * files or compile arbitrary source themselves.
+ */
+export async function publishCompiledDocArtifact(
+  workspaceId: string,
+  source: string,
+  ext: string,
+  referencedInputIdentity: string
+): Promise<void> {
+  if (!referencedInputIdentity) {
+    throw new Error('Published compiled document identity must not be empty')
+  }
+  const key = publishedArtifactPointerKey(workspaceId, source, ext)
+  const existing = await loadPublishedArtifactPointer(key)
+  if (existing?.referencedInputIdentity === referencedInputIdentity) return
+  const pointer: PublishedArtifactPointer = { version: 1, referencedInputIdentity }
+  try {
+    await uploadFile({
+      file: Buffer.from(JSON.stringify(pointer), 'utf-8'),
+      fileName: `doc.${ext}.published.json`,
+      contentType: 'application/json',
+      context: 'copilot',
+      customKey: key,
+      preserveKey: true,
+    })
+  } catch (error) {
+    logger.error('Failed to publish compiled doc artifact', {
+      key,
+      error: getErrorMessage(error),
+    })
+    throw toError(error)
+  }
+}
+
+/** Loads an artifact previously published by an authorized compile, or null before cutover. */
+export async function loadPublishedCompiledDoc(
+  workspaceId: string,
+  source: string,
+  ext: string
+): Promise<Buffer | null> {
+  const key = publishedArtifactPointerKey(workspaceId, source, ext)
+  const pointer = await loadPublishedArtifactPointer(key)
+  if (!pointer) return null
+  const artifact = await loadCompiledDoc(workspaceId, source, ext, pointer.referencedInputIdentity)
+  if (!artifact) throw new Error(`Published compiled document artifact is missing: ${key}`)
+  return artifact
+}
+
 /**
  * Stores the compiled binary as the source's associated S3 artifact.
  *
@@ -71,6 +156,9 @@ export async function storeCompiledDoc(
       customKey: key,
       preserveKey: true,
     })
+    if (referencedInputIdentity) {
+      await publishCompiledDocArtifact(workspaceId, source, ext, referencedInputIdentity)
+    }
   } catch (err) {
     logger.error('Failed to store compiled doc artifact', {
       key,
diff --git a/apps/sim/lib/copilot/tools/server/files/doc-servable.test.ts b/apps/sim/lib/copilot/tools/server/files/doc-servable.test.ts
index d7b4081a700..336ebe43491 100644
--- a/apps/sim/lib/copilot/tools/server/files/doc-servable.test.ts
+++ b/apps/sim/lib/copilot/tools/server/files/doc-servable.test.ts
@@ -7,6 +7,8 @@ import { afterAll, beforeEach, describe, expect, it, vi } from 'vitest'
 const {
   mockExecuteInSandbox,
   mockLoadCompiledDoc,
+  mockLoadPublishedCompiledDoc,
+  mockPublishCompiledDocArtifact,
   mockReadWorkspaceFileContent,
   mockReadWorkspaceFileMetadata,
   mockRunSandboxTask,
@@ -14,6 +16,8 @@ const {
 } = vi.hoisted(() => ({
   mockExecuteInSandbox: vi.fn(),
   mockLoadCompiledDoc: vi.fn(),
+  mockLoadPublishedCompiledDoc: vi.fn(),
+  mockPublishCompiledDocArtifact: vi.fn(),
   mockReadWorkspaceFileContent: vi.fn(),
   mockReadWorkspaceFileMetadata: vi.fn(),
   mockRunSandboxTask: vi.fn(),
@@ -38,6 +42,8 @@ vi.mock('@/lib/workspace-files/application/read-workspace-file-metadata', () =>
 }))
 vi.mock('./doc-compiled-store', () => ({
   loadCompiledDoc: mockLoadCompiledDoc,
+  loadPublishedCompiledDoc: mockLoadPublishedCompiledDoc,
+  publishCompiledDocArtifact: mockPublishCompiledDocArtifact,
   storeCompiledDoc: mockStoreCompiledDoc,
 }))
 vi.mock('@/app/api/files/utils', () => ({
@@ -72,6 +78,7 @@ describe('resolveServableDocBytes', () => {
   beforeEach(() => {
     vi.clearAllMocks()
     setEnvFlags({ isDocSandboxEnabled: true })
+    mockLoadPublishedCompiledDoc.mockResolvedValue(null)
   })
 
   it('swaps generated-doc source for the compiled artifact + binary content type', async () => {
@@ -201,6 +208,65 @@ describe('resolveServableDocBytes', () => {
     expect(mockStoreCompiledDoc).not.toHaveBeenCalled()
   })
 
+  it('serves the dependency-bound artifact published by an authorized compile', async () => {
+    const source = Buffer.from(`image = await getFileBase64('reference-1')`, 'utf-8')
+    const publishedArtifact = Buffer.from('%PDF-published')
+    mockLoadPublishedCompiledDoc.mockResolvedValue(publishedArtifact)
+
+    await expect(resolveServableDoc(WORKSPACE_ID, source, 'report.pdf')).resolves.toEqual({
+      kind: 'artifact',
+      buffer: publishedArtifact,
+      contentType: 'application/pdf',
+    })
+    expect(mockLoadPublishedCompiledDoc).toHaveBeenCalledWith(
+      WORKSPACE_ID,
+      source.toString('utf-8'),
+      'pdf'
+    )
+    expect(mockLoadCompiledDoc).not.toHaveBeenCalled()
+    expect(mockReadWorkspaceFileMetadata).not.toHaveBeenCalled()
+  })
+
+  it('fails fast when a private referenced document loses its Principal', async () => {
+    const source = Buffer.from(`image = await getFileBase64('reference-1')`, 'utf-8')
+
+    await expect(
+      resolveServableDocBytes({
+        rawBuffer: source,
+        fileName: 'report.pdf',
+        workspaceId: WORKSPACE_ID,
+      })
+    ).rejects.toThrow(
+      'Referenced document resolution requires an authorized workspace file principal'
+    )
+    expect(mockLoadPublishedCompiledDoc).toHaveBeenCalledWith(
+      WORKSPACE_ID,
+      source.toString('utf-8'),
+      'pdf'
+    )
+    expect(mockLoadCompiledDoc).not.toHaveBeenCalled()
+  })
+
+  it('lets a principal-less private adapter use output published by an authorized compile', async () => {
+    const source = Buffer.from(`image = await getFileBase64('reference-1')`, 'utf-8')
+    const publishedArtifact = Buffer.from('%PDF-published')
+    mockLoadPublishedCompiledDoc.mockResolvedValue(publishedArtifact)
+
+    await expect(
+      resolveServableDocBytes({
+        rawBuffer: source,
+        fileName: 'report.pdf',
+        workspaceId: WORKSPACE_ID,
+      })
+    ).resolves.toEqual({
+      buffer: publishedArtifact,
+      contentType: 'application/pdf',
+    })
+    expect(mockReadWorkspaceFileMetadata).not.toHaveBeenCalled()
+    expect(mockReadWorkspaceFileContent).not.toHaveBeenCalled()
+    expect(mockLoadCompiledDoc).not.toHaveBeenCalled()
+  })
+
   it('does not apply model-only provenance policy while serving a public legacy artifact', async () => {
     const source = Buffer.from(`image = await getFileBase64('reference-1')`, 'utf-8')
     const legacyArtifact = Buffer.from('%PDF-legacy')
diff --git a/apps/sim/lib/uploads/utils/file-utils.server.test.ts b/apps/sim/lib/uploads/utils/file-utils.server.test.ts
index 19f8a4dea71..6cae5e88cfa 100644
--- a/apps/sim/lib/uploads/utils/file-utils.server.test.ts
+++ b/apps/sim/lib/uploads/utils/file-utils.server.test.ts
@@ -81,10 +81,13 @@ describe('downloadFileFromStorage context derivation', () => {
       context: 'execution',
     }
 
-    await downloadServableFileFromStorage(userFile, 'req-1', createLogger('test'))
+    const filePrincipal = { kind: 'session' as const, userId: 'user-1', sessionId: 'session-1' }
+    await downloadServableFileFromStorage(userFile, 'req-1', createLogger('test'), {
+      filePrincipal,
+    })
 
     expect(mockResolveServableDocBytes).toHaveBeenCalledWith(
-      expect.objectContaining({ workspaceId })
+      expect.objectContaining({ workspaceId, filePrincipal })
     )
   })
 })
diff --git a/apps/sim/lib/uploads/utils/file-utils.server.ts b/apps/sim/lib/uploads/utils/file-utils.server.ts
index ca8fa11bcb1..34d91991a45 100644
--- a/apps/sim/lib/uploads/utils/file-utils.server.ts
+++ b/apps/sim/lib/uploads/utils/file-utils.server.ts
@@ -1,3 +1,4 @@
+import type { Principal } from '@sim/auth/principal'
 import { createLogger, type Logger } from '@sim/logger'
 import { getErrorMessage } from '@sim/utils/errors'
 import { getMaxExecutionTimeout } from '@/lib/core/execution-limits'
@@ -403,7 +404,12 @@ export async function downloadServableFileFromStorage(
   userFile: UserFile,
   requestId: string,
   logger: Logger,
-  options: { maxBytes?: number; signal?: AbortSignal; ownerKey?: string } = {}
+  options: {
+    maxBytes?: number
+    signal?: AbortSignal
+    ownerKey?: string
+    filePrincipal?: Principal
+  } = {}
 ): Promise<ServableFile> {
   const buffer = await downloadFileFromStorage(userFile, requestId, logger, {
     maxBytes: options.maxBytes,
@@ -430,6 +436,7 @@ export async function downloadServableFileFromStorage(
     rawBuffer: buffer,
     fileName: userFile.name,
     workspaceId,
+    filePrincipal: options.filePrincipal,
     ownerKey: options.ownerKey,
     signal: options.signal,
   })
diff --git a/apps/sim/lib/workspace-files/api/index.ts b/apps/sim/lib/workspace-files/api/index.ts
index dd0b8f04359..f4c93a1ad9a 100644
--- a/apps/sim/lib/workspace-files/api/index.ts
+++ b/apps/sim/lib/workspace-files/api/index.ts
@@ -3,5 +3,6 @@ export { internalFileErrorPolicies } from '@/lib/workspace-files/api/internal-er
 export { internalFilePresenters } from '@/lib/workspace-files/api/internal-presenters'
 export {
   internalSessionOrExecutorAuth,
+  internalWorkspaceFileServeAuth,
   v2FileErrorPolicies,
 } from '@/lib/workspace-files/api/route-policies'
diff --git a/apps/sim/lib/workspace-files/api/route-policies.ts b/apps/sim/lib/workspace-files/api/route-policies.ts
index 49de1bbbdba..4698ba8afc4 100644
--- a/apps/sim/lib/workspace-files/api/route-policies.ts
+++ b/apps/sim/lib/workspace-files/api/route-policies.ts
@@ -14,6 +14,15 @@ export const internalSessionOrExecutorAuth = createInternalSessionOrExecutorAuth
   },
 })
 
+/**
+ * Generated-document serving authorizes the root file and every referenced input. Its executor
+ * Principal is therefore intentionally workspace-scoped; a file-scoped Principal could authorize
+ * the root or one dependency, but never the full dependency graph.
+ */
+export const internalWorkspaceFileServeAuth = createInternalSessionOrExecutorAuth({
+  audience: WORKSPACE_FILES_DELEGATION_AUDIENCE,
+})
+
 export const v2FileErrorPolicies = {
   default: v2OrchestrationErrorPolicy,
   concealResourceAuthorization: createV2ResourceConcealmentPolicy({
diff --git a/apps/sim/lib/workspace-files/application/download-workspace-file-items.test.ts b/apps/sim/lib/workspace-files/application/download-workspace-file-items.test.ts
index fd017ba1b02..57f270b34f7 100644
--- a/apps/sim/lib/workspace-files/application/download-workspace-file-items.test.ts
+++ b/apps/sim/lib/workspace-files/application/download-workspace-file-items.test.ts
@@ -30,11 +30,13 @@ const {
 vi.mock('@/lib/uploads/contexts/workspace', () => ({
   buildWorkspaceFileFolderPathMap: (folders: Array<{ id: string; path?: string; name: string }>) =>
     new Map(folders.map((folder) => [folder.id, folder.path ?? folder.name])),
-  fetchServableWorkspaceFileBuffer: mockFetchServable,
   listWorkspaceFileFolders: mockListFolders,
   listWorkspaceFiles: mockListFiles,
   loadWorkspaceFileOperationContext: mockLoadContext,
 }))
+vi.mock('@/lib/workspace-files/application/fetch-servable-workspace-file-buffer', () => ({
+  fetchAuthorizedServableWorkspaceFileBuffer: mockFetchServable,
+}))
 vi.mock('@sim/platform-authz/workspace', () => ({
   permissionSatisfies: (actual: string | null, required: string) =>
     actual === 'admin' || actual === required || (actual === 'write' && required === 'read'),
@@ -161,9 +163,11 @@ describe('downloadWorkspaceFileItems', () => {
 
     expect(result.filesToZip[0].id).toBe('f1')
     expect(result.renderedDocuments.get('f1')).toEqual(Buffer.from('rendered'))
-    expect(mockFetchServable).toHaveBeenCalledWith(expect.objectContaining({ id: 'f1' }), {
-      maxBytes: 50 * 1024 * 1024,
-    })
+    expect(mockFetchServable).toHaveBeenCalledWith(
+      expect.objectContaining({ id: 'f1' }),
+      principal,
+      { maxBytes: 50 * 1024 * 1024 }
+    )
   })
 
   it('returns typed validation and conflict failures without recording audit', async () => {
diff --git a/apps/sim/lib/workspace-files/application/download-workspace-file-items.ts b/apps/sim/lib/workspace-files/application/download-workspace-file-items.ts
index afbe5e026ef..7291fc7ec5a 100644
--- a/apps/sim/lib/workspace-files/application/download-workspace-file-items.ts
+++ b/apps/sim/lib/workspace-files/application/download-workspace-file-items.ts
@@ -1,9 +1,9 @@
 import { AuditAction, AuditResourceType } from '@sim/audit'
+import type { AuthorizedWorkspaceUseCaseContext } from '@/lib/core/application'
 import { OrchestrationError } from '@/lib/core/orchestration/types'
 import { PayloadSizeLimitError } from '@/lib/core/utils/stream-limits'
 import {
   buildWorkspaceFileFolderPathMap,
-  fetchServableWorkspaceFileBuffer,
   listWorkspaceFileFolders,
   listWorkspaceFiles,
   loadWorkspaceFileOperationContext,
@@ -16,6 +16,7 @@ import {
   needsRenderedArtifact,
 } from '@/lib/uploads/utils/file-utils'
 import { defineAuthorizedWorkspaceFileUseCase } from '@/lib/workspace-files/application/authorized-workspace-file-use-case'
+import { fetchAuthorizedServableWorkspaceFileBuffer } from '@/lib/workspace-files/application/fetch-servable-workspace-file-buffer'
 import { fileOperations } from '@/lib/workspace-files/application/operations'
 
 export const MAX_ZIP_DOWNLOAD_FILES = 100
@@ -61,10 +62,12 @@ function validationError(message: string): never {
 async function executeDownloadWorkspaceFileItems({
   input,
   context,
-}: {
-  input: DownloadWorkspaceFileItemsInput
-  context: Awaited<ReturnType<typeof resolveDownloadContext>>
-}): Promise<DownloadWorkspaceFileItemsResult> {
+  principal,
+}: AuthorizedWorkspaceUseCaseContext<
+  typeof fileOperations.download,
+  DownloadWorkspaceFileItemsInput,
+  Awaited<ReturnType<typeof resolveDownloadContext>>
+>): Promise<DownloadWorkspaceFileItemsResult> {
   const fileIds = [...new Set(input.fileIds)]
   const folderIds = [...new Set(input.folderIds)]
   if (fileIds.length > MAX_REQUESTED_FILE_IDS) {
@@ -118,7 +121,9 @@ async function executeDownloadWorkspaceFileItems({
     const remaining = Math.max(0, MAX_ZIP_DOWNLOAD_BYTES - reservedForStreamed - renderedBytes)
     const allowance = Math.min(remaining, MAX_RENDERED_DOCUMENT_BYTES)
     try {
-      const { buffer } = await fetchServableWorkspaceFileBuffer(file, { maxBytes: allowance })
+      const { buffer } = await fetchAuthorizedServableWorkspaceFileBuffer(file, principal, {
+        maxBytes: allowance,
+      })
       renderedBytes += buffer.length
       renderedDocuments.set(file.id, buffer)
     } catch (error) {
diff --git a/apps/sim/lib/workspace-files/application/download-workspace-file.test.ts b/apps/sim/lib/workspace-files/application/download-workspace-file.test.ts
index 0b563b59afe..a8e950e2df1 100644
--- a/apps/sim/lib/workspace-files/application/download-workspace-file.test.ts
+++ b/apps/sim/lib/workspace-files/application/download-workspace-file.test.ts
@@ -27,11 +27,14 @@ vi.mock('@sim/platform-authz/workspace', () => ({
 }))
 
 vi.mock('@/lib/uploads/contexts/workspace/workspace-file-manager', () => ({
-  fetchServableWorkspaceFileBuffer: mocks.fetchServable,
   getWorkspaceFile: mocks.getFile,
   loadActiveWorkspaceFileContext: mocks.loadContext,
 }))
 
+vi.mock('@/lib/workspace-files/application/fetch-servable-workspace-file-buffer', () => ({
+  fetchAuthorizedServableWorkspaceFileBuffer: mocks.fetchServable,
+}))
+
 vi.mock('@/lib/uploads/core/storage-service', () => ({
   downloadFileStream: mocks.downloadStream,
 }))
@@ -194,6 +197,7 @@ describe('workspace file downloads', () => {
 
     expect(mocks.fetchServable).toHaveBeenCalledWith(
       generatedDoc,
+      SESSION,
       expect.objectContaining({ maxBytes: MAX_RENDERED_DOCUMENT_BYTES })
     )
   })
@@ -202,7 +206,7 @@ describe('workspace file downloads', () => {
   it('routes a record with no content type by its extension', async () => {
     await downloadStream('file-1')
 
-    expect(mocks.fetchServable).toHaveBeenCalledWith(file, expect.anything())
+    expect(mocks.fetchServable).toHaveBeenCalledWith(file, SESSION, expect.anything())
     expect(mocks.downloadStream).not.toHaveBeenCalled()
   })
 
diff --git a/apps/sim/lib/workspace-files/application/download-workspace-file.ts b/apps/sim/lib/workspace-files/application/download-workspace-file.ts
index 01a2fa507af..0d599f8bd23 100644
--- a/apps/sim/lib/workspace-files/application/download-workspace-file.ts
+++ b/apps/sim/lib/workspace-files/application/download-workspace-file.ts
@@ -5,7 +5,6 @@ import { nodeReadableToWebStream } from '@/lib/core/utils/node-stream'
 import { isPayloadSizeLimitError } from '@/lib/core/utils/stream-limits'
 import {
   type ActiveWorkspaceFileContext,
-  fetchServableWorkspaceFileBuffer,
   getWorkspaceFile,
 } from '@/lib/uploads/contexts/workspace/workspace-file-manager'
 import { downloadFileStream } from '@/lib/uploads/core/storage-service'
@@ -16,6 +15,7 @@ import {
   needsRenderedArtifact,
 } from '@/lib/uploads/utils/file-utils'
 import { defineAuthorizedWorkspaceFileUseCase } from '@/lib/workspace-files/application/authorized-workspace-file-use-case'
+import { fetchAuthorizedServableWorkspaceFileBuffer } from '@/lib/workspace-files/application/fetch-servable-workspace-file-buffer'
 import { fileOperations } from '@/lib/workspace-files/application/operations'
 import { resolveActiveWorkspaceFileContext } from '@/lib/workspace-files/application/workspace-file-context'
 
@@ -93,9 +93,16 @@ export const downloadWorkspaceFile = defineAuthorizedWorkspaceFileUseCase({
  * artifact that never appears. It stays a `conflict` only because the v2
  * envelope has no 422; the message is what distinguishes the two.
  */
-async function resolveRenderedArtifact(file: DownloadWorkspaceFileResult['file']) {
+async function resolveRenderedArtifact(
+  file: DownloadWorkspaceFileResult['file'],
+  filePrincipal: AuthorizedWorkspaceUseCaseContext<
+    typeof fileOperations.download,
+    DownloadWorkspaceFileInput,
+    ActiveWorkspaceFileContext
+  >['principal']
+) {
   try {
-    return await fetchServableWorkspaceFileBuffer(file, {
+    return await fetchAuthorizedServableWorkspaceFileBuffer(file, filePrincipal, {
       maxBytes: MAX_RENDERED_DOCUMENT_BYTES,
     })
   } catch (error) {
@@ -118,6 +125,7 @@ async function resolveRenderedArtifact(file: DownloadWorkspaceFileResult['file']
 
 async function executeDownloadWorkspaceFileStream({
   context,
+  principal,
 }: AuthorizedWorkspaceUseCaseContext<
   typeof fileOperations.download,
   DownloadWorkspaceFileInput,
@@ -138,7 +146,7 @@ async function executeDownloadWorkspaceFileStream({
    * double peak memory.
    */
   if (needsRenderedArtifact(file.type, file.name)) {
-    const { buffer, contentType } = await resolveRenderedArtifact(file)
+    const { buffer, contentType } = await resolveRenderedArtifact(file, principal)
     return {
       file,
       stream: new ReadableStream<Uint8Array>({
diff --git a/apps/sim/lib/workspace-files/application/fetch-servable-workspace-file-buffer.ts b/apps/sim/lib/workspace-files/application/fetch-servable-workspace-file-buffer.ts
new file mode 100644
index 00000000000..f7456f44d73
--- /dev/null
+++ b/apps/sim/lib/workspace-files/application/fetch-servable-workspace-file-buffer.ts
@@ -0,0 +1,35 @@
+import type { Principal } from '@sim/auth/principal'
+import { createLogger } from '@sim/logger'
+import { generateRequestId } from '@/lib/core/utils/request'
+import type { WorkspaceFileRecord } from '@/lib/uploads/contexts/workspace'
+import { downloadServableFileFromStorage } from '@/lib/uploads/utils/file-utils.server'
+
+const logger = createLogger('FetchServableWorkspaceFileBuffer')
+
+/**
+ * Resolves the rendered bytes of an already-authorized workspace file while preserving the
+ * Principal for any referenced-file reads performed by the document compiler.
+ */
+export async function fetchAuthorizedServableWorkspaceFileBuffer(
+  fileRecord: WorkspaceFileRecord,
+  filePrincipal: Principal,
+  options: { maxBytes?: number; signal?: AbortSignal; requestId?: string } = {}
+): Promise<{ buffer: Buffer; contentType: string }> {
+  return downloadServableFileFromStorage(
+    {
+      id: fileRecord.id,
+      name: fileRecord.name,
+      url: fileRecord.url ?? fileRecord.path,
+      size: fileRecord.size,
+      type: fileRecord.type,
+      key: fileRecord.key,
+      context: fileRecord.storageContext ?? 'workspace',
+    },
+    options.requestId ?? generateRequestId(),
+    logger,
+    {
+      ...options,
+      filePrincipal,
+    }
+  )
+}
diff --git a/apps/sim/lib/workspace-files/application/read-workspace-file-content-by-key.test.ts b/apps/sim/lib/workspace-files/application/read-workspace-file-content-by-key.test.ts
new file mode 100644
index 00000000000..39943c138e4
--- /dev/null
+++ b/apps/sim/lib/workspace-files/application/read-workspace-file-content-by-key.test.ts
@@ -0,0 +1,92 @@
+/**
+ * @vitest-environment node
+ */
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+const mocks = vi.hoisted(() => ({
+  fetchContent: vi.fn(),
+  getFile: vi.fn(),
+  getMetadata: vi.fn(),
+  loadContext: vi.fn(),
+  resolvePermission: vi.fn(),
+}))
+
+vi.mock('@/lib/uploads/contexts/workspace', () => ({
+  fetchWorkspaceFileBuffer: mocks.fetchContent,
+  getWorkspaceFile: mocks.getFile,
+  loadActiveWorkspaceFileContext: mocks.loadContext,
+}))
+
+vi.mock('@/lib/uploads/server/metadata', () => ({
+  getFileMetadataByKey: mocks.getMetadata,
+}))
+
+vi.mock('@sim/platform-authz/workspace', () => ({
+  permissionSatisfies: () => true,
+  resolveEffectiveWorkspacePermission: mocks.resolvePermission,
+}))
+
+import { readWorkspaceFileContentByKey } from '@/lib/workspace-files/application/read-workspace-file-content-by-key'
+
+const principal = { kind: 'session' as const, userId: 'user-1', sessionId: 'session-1' }
+const context = {
+  fileId: 'file-1',
+  workspaceId: 'workspace-1',
+  workspaceOrganizationId: null,
+  allowPersonalApiKeys: true,
+  billedAccountUserId: 'billing-owner',
+}
+const file = {
+  id: 'file-1',
+  workspaceId: 'workspace-1',
+  name: 'report.pdf',
+  key: 'workspace/workspace-1/report.pdf',
+  path: '/api/files/serve/workspace/workspace-1/report.pdf',
+  size: 6,
+  type: 'text/x-python-pdf',
+  uploadedBy: 'user-1',
+  uploadedAt: new Date('2026-08-01T00:00:00Z'),
+  updatedAt: new Date('2026-08-01T00:00:00Z'),
+}
+
+describe('readWorkspaceFileContentByKey', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+    mocks.getMetadata.mockResolvedValue({
+      id: file.id,
+      workspaceId: file.workspaceId,
+      key: file.key,
+      context: 'workspace',
+    })
+    mocks.loadContext.mockResolvedValue(context)
+    mocks.resolvePermission.mockResolvedValue('read')
+    mocks.getFile.mockResolvedValue(file)
+    mocks.fetchContent.mockResolvedValue(Buffer.from('source'))
+  })
+
+  it('authorizes the canonical file before returning its stored bytes', async () => {
+    await expect(
+      readWorkspaceFileContentByKey.execute({
+        principal,
+        input: { key: file.key, assertedWorkspaceId: file.workspaceId },
+      })
+    ).resolves.toEqual({ file, content: Buffer.from('source') })
+
+    expect(mocks.getFile).toHaveBeenCalledWith(file.workspaceId, file.id, {
+      throwOnError: true,
+    })
+    expect(mocks.fetchContent).toHaveBeenCalledWith(file)
+  })
+
+  it('rejects a stale key instead of serving the file current at the same ID', async () => {
+    mocks.getFile.mockResolvedValue({ ...file, key: `${file.key}.new` })
+
+    await expect(
+      readWorkspaceFileContentByKey.execute({
+        principal,
+        input: { key: file.key, assertedWorkspaceId: file.workspaceId },
+      })
+    ).rejects.toMatchObject({ code: 'not_found' })
+    expect(mocks.fetchContent).not.toHaveBeenCalled()
+  })
+})
diff --git a/apps/sim/lib/workspace-files/application/read-workspace-file-content-by-key.ts b/apps/sim/lib/workspace-files/application/read-workspace-file-content-by-key.ts
new file mode 100644
index 00000000000..d5629ed275b
--- /dev/null
+++ b/apps/sim/lib/workspace-files/application/read-workspace-file-content-by-key.ts
@@ -0,0 +1,57 @@
+import type { AuthorizedWorkspaceUseCaseContext } from '@/lib/core/application'
+import { OrchestrationError } from '@/lib/core/orchestration/types'
+import {
+  type ActiveWorkspaceFileContext,
+  fetchWorkspaceFileBuffer,
+  getWorkspaceFile,
+  loadActiveWorkspaceFileContext,
+  type WorkspaceFileRecord,
+} from '@/lib/uploads/contexts/workspace'
+import { getFileMetadataByKey } from '@/lib/uploads/server/metadata'
+import { defineAuthorizedWorkspaceFileUseCase } from '@/lib/workspace-files/application/authorized-workspace-file-use-case'
+import { fileOperations } from '@/lib/workspace-files/application/operations'
+
+export interface ReadWorkspaceFileContentByKeyInput {
+  key: string
+  assertedWorkspaceId?: string
+}
+
+export interface ReadWorkspaceFileContentByKeyResult {
+  file: WorkspaceFileRecord
+  content: Buffer
+}
+
+async function executeReadWorkspaceFileContentByKey({
+  input,
+  context,
+}: AuthorizedWorkspaceUseCaseContext<
+  typeof fileOperations.readContent,
+  ReadWorkspaceFileContentByKeyInput,
+  ActiveWorkspaceFileContext
+>): Promise<ReadWorkspaceFileContentByKeyResult> {
+  const file = await getWorkspaceFile(context.workspaceId, context.fileId, {
+    throwOnError: true,
+  })
+  if (!file || file.key !== input.key) throw new OrchestrationError('not_found', 'File not found')
+  return { file, content: await fetchWorkspaceFileBuffer(file) }
+}
+
+export const readWorkspaceFileContentByKey = defineAuthorizedWorkspaceFileUseCase({
+  operation: fileOperations.readContent,
+  async resolveContext({ input }) {
+    const metadata = await getFileMetadataByKey(input.key, 'workspace')
+    if (
+      !metadata?.workspaceId ||
+      (input.assertedWorkspaceId !== undefined &&
+        input.assertedWorkspaceId !== metadata.workspaceId)
+    ) {
+      throw new OrchestrationError('not_found', 'File not found')
+    }
+    const canonical = await loadActiveWorkspaceFileContext(metadata.id)
+    if (!canonical || canonical.workspaceId !== metadata.workspaceId) {
+      throw new OrchestrationError('not_found', 'File not found')
+    }
+    return canonical
+  },
+  execute: executeReadWorkspaceFileContentByKey,
+})