simstudioai · waleedlatif1 · Aug 10, 2026 · Aug 10, 2026
diff --git a/apps/sim/app/api/files/multipart/route.test.ts b/apps/sim/app/api/files/multipart/route.test.ts
@@ -52,19 +52,19 @@ vi.mock('@/lib/uploads/providers/blob/client', () => ({
 }))
 
 vi.mock('@/lib/uploads/contexts/execution/utils', () => ({
-  generateExecutionAttachmentKey: mockGenerateExecutionAttachmentKey,
+  generateUniqueExecutionFileKey: mockGenerateUniqueExecutionFileKey,
 }))
 
 vi.mock('@/lib/workspaces/permissions/utils', () => permissionsMock)
 
 const {
   mockCheckStorageQuota,
-  mockGenerateExecutionAttachmentKey,
+  mockGenerateUniqueExecutionFileKey,
   mockInitiateS3MultipartUpload,
   mockResolveStorageBillingContext,
 } = vi.hoisted(() => ({
   mockCheckStorageQuota: vi.fn(),
-  mockGenerateExecutionAttachmentKey: vi.fn(),
+  mockGenerateUniqueExecutionFileKey: vi.fn(),
   mockInitiateS3MultipartUpload: vi.fn(),
   mockResolveStorageBillingContext: vi.fn(),
 }))
@@ -250,7 +250,7 @@ describe('POST /api/files/multipart action=initiate quota enforcement', () => {
     mockResolveStorageBillingContext.mockResolvedValue(STORAGE_CONTEXT)
     mockCheckStorageQuota.mockResolvedValue({ allowed: true })
     mockInitiateS3MultipartUpload.mockResolvedValue({ uploadId: 'up-1', key: 'k/file.bin' })
-    mockGenerateExecutionAttachmentKey.mockImplementation(
+    mockGenerateUniqueExecutionFileKey.mockImplementation(
       (
         context: { workspaceId: string; workflowId: string; executionId: string },
         fileName: string
@@ -311,7 +311,7 @@ describe('POST /api/files/multipart action=initiate quota enforcement', () => {
   })
 
   it('allocates distinct multipart keys for duplicate execution attachment names', async () => {
-    mockGenerateExecutionAttachmentKey
+    mockGenerateUniqueExecutionFileKey
       .mockReturnValueOnce('execution/ws-1/wf-1/exec-1/one-output.bin')
       .mockReturnValueOnce('execution/ws-1/wf-1/exec-1/two-output.bin')
     mockInitiateS3MultipartUpload.mockImplementation(async ({ customKey }) => ({

diff --git a/apps/sim/app/api/files/multipart/route.ts b/apps/sim/app/api/files/multipart/route.ts
@@ -215,10 +215,10 @@ export const POST = withRouteHandler(async (request: NextRequest) => {
               { status: 400 }
             )
           }
-          const { generateExecutionAttachmentKey } = await import(
+          const { generateUniqueExecutionFileKey } = await import(
             '@/lib/uploads/contexts/execution/utils'
           )
-          customKey = generateExecutionAttachmentKey(
+          customKey = generateUniqueExecutionFileKey(
             { workspaceId, workflowId, executionId },
             fileName
           )

diff --git a/apps/sim/app/api/files/presigned/route.test.ts b/apps/sim/app/api/files/presigned/route.test.ts
@@ -24,7 +24,7 @@ const {
   mockIsUsingCloudStorageUploads,
   mockGetUserEntityPermissions,
   mockGenerateWorkspaceFileKey,
-  mockGenerateExecutionAttachmentKey,
+  mockGenerateUniqueExecutionFileKey,
   mockInsertFileMetadata,
   mockCheckStorageQuotaForBillingContext,
   mockDecrementStorageUsageForBillingContext,
@@ -52,7 +52,7 @@ const {
   mockGenerateWorkspaceFileKey: vi.fn(
     (workspaceId: string, fileName: string) => `workspace/${workspaceId}/${fileName}`
   ),
-  mockGenerateExecutionAttachmentKey: vi.fn(
+  mockGenerateUniqueExecutionFileKey: vi.fn(
     (ctx: { workspaceId: string; workflowId: string; executionId: string }, fileName: string) =>
       `execution/${ctx.workspaceId}/${ctx.workflowId}/${ctx.executionId}/attachment-${fileName}`
   ),
@@ -110,7 +110,7 @@ vi.mock('@/lib/uploads/contexts/workspace/workspace-file-manager', () => ({
 }))
 
 vi.mock('@/lib/uploads/contexts/execution/utils', () => ({
-  generateExecutionAttachmentKey: mockGenerateExecutionAttachmentKey,
+  generateUniqueExecutionFileKey: mockGenerateUniqueExecutionFileKey,
 }))
 
 vi.mock('@/lib/uploads/server/metadata', () => ({
@@ -752,7 +752,7 @@ describe('/api/files/presigned', () => {
   describe('execution uploads', () => {
     it('allocates distinct create-only keys for duplicate attachment names', async () => {
       setupFileApiMocks({ cloudEnabled: true, storageProvider: 's3' })
-      mockGenerateExecutionAttachmentKey
+      mockGenerateUniqueExecutionFileKey
         .mockReturnValueOnce('execution/ws-1/wf-1/exec-1/one-output.txt')
         .mockReturnValueOnce('execution/ws-1/wf-1/exec-1/two-output.txt')
 

diff --git a/apps/sim/app/api/files/presigned/route.ts b/apps/sim/app/api/files/presigned/route.ts
@@ -11,7 +11,7 @@ import { getSession } from '@/lib/auth'
 import { withRouteHandler } from '@/lib/core/utils/with-route-handler'
 import { CopilotFiles } from '@/lib/uploads'
 import { getServeStoragePrefix } from '@/lib/uploads/config'
-import { generateExecutionAttachmentKey } from '@/lib/uploads/contexts/execution/utils'
+import { generateUniqueExecutionFileKey } from '@/lib/uploads/contexts/execution/utils'
 import { generateKnowledgeBaseFileKey } from '@/lib/uploads/contexts/knowledge-base/knowledge-base-file-manager'
 import { generateWorkspaceFileKey } from '@/lib/uploads/contexts/workspace/workspace-file-manager'
 import { generatePresignedUploadUrl, hasCloudStorage } from '@/lib/uploads/core/storage-service'
@@ -222,7 +222,7 @@ export const POST = withRouteHandler(async (request: NextRequest) => {
         throw new ValidationError(fileValidationError.message)
       }
 
-      const customKey = generateExecutionAttachmentKey(
+      const customKey = generateUniqueExecutionFileKey(
         { workspaceId, workflowId, executionId },
         fileName
       )

diff --git a/apps/sim/lib/execution/payloads/store.ts b/apps/sim/lib/execution/payloads/store.ts
@@ -16,7 +16,7 @@ import {
   isValidLargeValueKey,
   readLargeValueRefFromStorage,
 } from '@/lib/execution/payloads/materialization.server'
-import { generateExecutionFileKey } from '@/lib/uploads/contexts/execution/utils'
+import { generateLargeValuePayloadKey } from '@/lib/uploads/contexts/execution/utils'
 
 const logger = createLogger('LargeExecutionPayloadStore')
 
@@ -75,10 +75,7 @@ async function persistValue(
     return undefined
   }
 
-  const key = generateExecutionFileKey(
-    { workspaceId, workflowId, executionId },
-    `large-value-${id}.json`
-  )
+  const key = generateLargeValuePayloadKey({ workspaceId, workflowId, executionId }, id)
 
   try {
     const { StorageService } = await import('@/lib/uploads')

diff --git a/apps/sim/lib/uploads/contexts/execution/execution-file-manager.test.ts b/apps/sim/lib/uploads/contexts/execution/execution-file-manager.test.ts
@@ -23,7 +23,13 @@ vi.mock('@/lib/uploads/providers/s3/client', () => ({
 
 import { uploadExecutionFile } from '@/lib/uploads/contexts/execution/execution-file-manager'
 
-describe('uploadExecutionFile replacement compatibility', () => {
+const context = {
+  workspaceId: 'workspace-1',
+  workflowId: 'workflow-1',
+  executionId: 'execution-1',
+}
+
+describe('uploadExecutionFile key allocation', () => {
   beforeEach(() => {
     vi.clearAllMocks()
     resetDbChainMock()
@@ -35,57 +41,27 @@ describe('uploadExecutionFile replacement compatibility', () => {
       type: contentType,
     }))
     mockGetPresignedUrlWithConfig.mockResolvedValue('https://example.com/download')
+    dbChainMockFns.limit.mockResolvedValue([])
+    dbChainMockFns.returning.mockResolvedValue([{ id: 'file-1' }])
   })
 
-  it('allows changed bytes and content type at the same execution-scoped key', async () => {
-    const context = {
-      workspaceId: 'workspace-1',
-      workflowId: 'workflow-1',
-      executionId: 'execution-1',
-    }
-    const key = 'execution/workspace-1/workflow-1/execution-1/result.txt'
-    const existingMetadata = {
-      id: 'file-1',
-      key,
-      userId: 'user-1',
-      workspaceId: 'workspace-1',
-      folderId: null,
-      context: 'execution',
-      originalName: key,
-      displayName: key,
-      contentType: 'text/plain',
-      size: 3,
-      deletedAt: null,
-    }
-
-    dbChainMockFns.limit
-      .mockResolvedValueOnce([])
-      .mockResolvedValueOnce([])
-      .mockResolvedValueOnce([existingMetadata])
-    dbChainMockFns.returning.mockResolvedValueOnce([existingMetadata])
-
+  it('gives same-named files in one execution distinct keys', async () => {
     const first = await uploadExecutionFile(
       context,
-      Buffer.from('old'),
-      'result.txt',
-      'text/plain',
+      Buffer.alloc(13575),
+      'image.png',
+      'image/png',
       'user-1'
     )
     const second = await uploadExecutionFile(
       context,
-      Buffer.from('{"new":true}'),
-      'result.txt',
-      'application/json',
+      Buffer.alloc(37226),
+      'image.png',
+      'image/png',
       'user-1'
     )
 
-    expect(first.key).toBe(key)
-    expect(second).toMatchObject({
-      key,
-      size: 12,
-      type: 'application/json',
-    })
-    expect(mockUploadToS3).toHaveBeenCalledTimes(2)
-    expect(dbChainMockFns.insert).toHaveBeenCalledTimes(1)
+    expect(first.key).not.toBe(second.key)
+    expect(dbChainMockFns.insert).toHaveBeenCalledTimes(2)
   })
 })
diff --git a/apps/sim/lib/uploads/contexts/execution/execution-file-manager.ts b/apps/sim/lib/uploads/contexts/execution/execution-file-manager.ts
@@ -3,7 +3,10 @@ import { getErrorMessage } from '@sim/utils/errors'
 import { isPayloadSizeLimitError } from '@/lib/core/utils/stream-limits'
 import { isUserFileWithMetadata } from '@/lib/core/utils/user-file'
 import type { ExecutionContext } from '@/lib/uploads/contexts/execution/utils'
-import { generateExecutionFileKey, generateFileId } from '@/lib/uploads/contexts/execution/utils'
+import {
+  generateFileId,
+  generateUniqueExecutionFileKey,
+} from '@/lib/uploads/contexts/execution/utils'
 import type { UserFile } from '@/executor/types'
 
 const logger = createLogger('ExecutionFileStorage')
@@ -78,7 +81,7 @@ export async function uploadExecutionFile(
     bufferSize: fileBuffer.length,
   })
 
-  const storageKey = generateExecutionFileKey(context, fileName)
+  const storageKey = generateUniqueExecutionFileKey(context, fileName)
   const fileId = generateFileId()
 
   logger.info(`Generated storage key: "${storageKey}" for file: ${fileName}`)

diff --git a/apps/sim/lib/uploads/contexts/execution/utils.test.ts b/apps/sim/lib/uploads/contexts/execution/utils.test.ts
@@ -3,8 +3,8 @@
  */
 import { describe, expect, it } from 'vitest'
 import {
-  generateExecutionAttachmentKey,
-  generateExecutionFileKey,
+  generateLargeValuePayloadKey,
+  generateUniqueExecutionFileKey,
 } from '@/lib/uploads/contexts/execution/utils'
 
 const context = {
@@ -14,25 +14,20 @@ const context = {
 }
 
 describe('execution storage keys', () => {
-  it('retains deterministic keys for internal execution artifacts', () => {
-    expect(generateExecutionFileKey(context, 'result.json')).toBe(
-      'execution/workspace-1/workflow-1/execution-1/result.json'
-    )
-    expect(generateExecutionFileKey(context, 'result.json')).toBe(
-      'execution/workspace-1/workflow-1/execution-1/result.json'
-    )
+  it('retains deterministic keys for large-value payloads', () => {
+    const key = 'execution/workspace-1/workflow-1/execution-1/large-value-lv_abc123.json'
+
+    expect(generateLargeValuePayloadKey(context, 'lv_abc123')).toBe(key)
+    expect(generateLargeValuePayloadKey(context, 'lv_abc123')).toBe(key)
   })
 
-  it('allocates unique create-only keys for duplicate browser attachment names', () => {
-    const first = generateExecutionAttachmentKey(context, 'report final.pdf')
-    const second = generateExecutionAttachmentKey(context, 'report final.pdf')
+  it('allocates unique keys for duplicate file names, keeping the name as the final segment', () => {
+    const first = generateUniqueExecutionFileKey(context, 'report final.pdf')
+    const second = generateUniqueExecutionFileKey(context, 'report final.pdf')
+    const shape = /^execution\/workspace-1\/workflow-1\/execution-1\/[0-9a-f-]+\/report-final\.pdf$/
 
-    expect(first).toMatch(
-      /^execution\/workspace-1\/workflow-1\/execution-1\/[0-9a-f-]+-report-final\.pdf$/
-    )
-    expect(second).toMatch(
-      /^execution\/workspace-1\/workflow-1\/execution-1\/[0-9a-f-]+-report-final\.pdf$/
-    )
+    expect(first).toMatch(shape)
+    expect(second).toMatch(shape)
     expect(first).not.toBe(second)
   })
 })
diff --git a/apps/sim/lib/uploads/contexts/execution/utils.ts b/apps/sim/lib/uploads/contexts/execution/utils.ts
@@ -13,28 +13,42 @@ export interface ExecutionContext {
 }
 
 /**
- * Generate execution-scoped storage key with explicit prefix
- * Format: execution/workspace_id/workflow_id/execution_id/filename
+ * Generate the deterministic storage key for a large-value execution payload.
+ * Format: execution/workspace_id/workflow_id/execution_id/large-value-<id>.json
+ *
+ * Takes the payload id rather than a file name so no user-supplied name can
+ * reach a key without a uniquifier — that is what silently overwrote same-named
+ * files before {@link generateUniqueExecutionFileKey} existed. Determinism is
+ * load-bearing here: the cleanup job matches these keys by LIKE pattern and
+ * re-storing the same payload must be idempotent.
  */
-export function generateExecutionFileKey(context: ExecutionContext, fileName: string): string {
+export function generateLargeValuePayloadKey(context: ExecutionContext, id: string): string {
   const { workspaceId, workflowId, executionId } = context
-  const safeFileName = sanitizeFileName(fileName)
+  const safeFileName = sanitizeFileName(`large-value-${id}.json`)
   return `execution/${workspaceId}/${workflowId}/${executionId}/${safeFileName}`
 }
 
 /**
- * Generates a unique execution-scoped key for browser attachments. Browser
- * uploads are create-only, and a single execution may contain multiple files
- * with the same display name. Internal execution artifacts intentionally keep
- * using {@link generateExecutionFileKey}'s deterministic replacement semantics.
+ * Generate a collision-free execution-scoped storage key.
+ * Format: execution/workspace_id/workflow_id/execution_id/unique_id/filename
+ *
+ * One execution routinely carries several files sharing a display name (two
+ * `image.png` screenshots in one Slack message, repeated tool outputs in a
+ * loop), which the deterministic key would overwrite. The unique id is its own
+ * path segment rather than a filename prefix so the last segment stays the
+ * original name — presigned URLs carry no content-disposition, so that segment
+ * is what a consumer sees.
+ *
+ * Large-value payloads, whose ids are already unique, keep using
+ * {@link generateLargeValuePayloadKey}.
  */
-export function generateExecutionAttachmentKey(
+export function generateUniqueExecutionFileKey(
   context: ExecutionContext,
   fileName: string
 ): string {
   const { workspaceId, workflowId, executionId } = context
   const safeFileName = sanitizeFileName(fileName)
-  return `execution/${workspaceId}/${workflowId}/${executionId}/${generateId()}-${safeFileName}`
+  return `execution/${workspaceId}/${workflowId}/${executionId}/${generateId()}/${safeFileName}`
 }
 
 /**
@@ -45,8 +59,7 @@ export function generateFileId(): string {
 }
 
 /**
- * Check if a key matches execution file pattern
- * Execution files have keys in format: execution/workspaceId/workflowId/executionId/filename
+ * Execution keys: execution/workspaceId/workflowId/executionId/[uniqueId/]filename
  */
 function matchesExecutionFilePattern(key: string): boolean {
   if (!key || key.startsWith('/api/') || key.startsWith('http')) {
@@ -65,7 +78,6 @@ function matchesExecutionFilePattern(key: string): boolean {
 
 /**
  * Check if a file is from execution storage based on its key pattern
- * Execution files have keys in format: execution/workspaceId/workflowId/executionId/filename
  */
 export function isExecutionFile(file: UserFile): boolean {
   if (!file.key) {