simstudioai · TheodoreSpeaks · Mar 19, 2026 · Mar 19, 2026 · Mar 19, 2026 · Mar 19, 2026
diff --git a/apps/sim/app/api/tools/file/manage/route.ts b/apps/sim/app/api/tools/file/manage/route.ts
@@ -0,0 +1,159 @@
+import { createLogger } from '@sim/logger'
+import { type NextRequest, NextResponse } from 'next/server'
+import { checkInternalAuth } from '@/lib/auth/hybrid'
+import { ensureAbsoluteUrl } from '@/lib/core/utils/urls'
+import {
+  downloadWorkspaceFile,
+  getWorkspaceFileByName,
+  updateWorkspaceFileContent,
+  uploadWorkspaceFile,
+} from '@/lib/uploads/contexts/workspace/workspace-file-manager'
+import { getFileExtension, getMimeTypeFromExtension } from '@/lib/uploads/utils/file-utils'
+
+export const dynamic = 'force-dynamic'
+
+const logger = createLogger('FileManageAPI')
+
+export async function POST(request: NextRequest) {
+  const auth = await checkInternalAuth(request, { requireWorkflowId: false })
+  if (!auth.success) {
+    return NextResponse.json({ success: false, error: auth.error }, { status: 401 })
+  }
+
+  const { searchParams } = new URL(request.url)
+  const userId = auth.userId || searchParams.get('userId')
+
+  if (!userId) {
+    return NextResponse.json({ success: false, error: 'userId is required' }, { status: 400 })
+  }
+
+  let body: Record<string, unknown>
+  try {
+    body = await request.json()
+  } catch {
+    return NextResponse.json({ success: false, error: 'Invalid JSON body' }, { status: 400 })
+  }
+
+  const workspaceId = (body.workspaceId as string) || searchParams.get('workspaceId')
+  if (!workspaceId) {
+    return NextResponse.json({ success: false, error: 'workspaceId is required' }, { status: 400 })
+  }
+
+  const operation = body.operation as string
+
+  try {
+    switch (operation) {
+      case 'write': {
+        const fileName = body.fileName as string | undefined
+        const content = body.content as string | undefined
+        const contentType = body.contentType as string | undefined
+
+        if (!fileName) {
+          return NextResponse.json(
+            { success: false, error: 'fileName is required for write operation' },
+            { status: 400 }
+          )
+        }
+
+        if (!content && content !== '') {
+          return NextResponse.json(
+            { success: false, error: 'content is required for write operation' },
+            { status: 400 }
+          )
+        }
+
+        const existing = await getWorkspaceFileByName(workspaceId, fileName)
+        if (existing) {
+          return NextResponse.json(
+            { success: false, error: `File already exists: "${fileName}"` },
+            { status: 409 }
+          )
+        }
+
+        const mimeType = contentType || getMimeTypeFromExtension(getFileExtension(fileName))
+        const fileBuffer = Buffer.from(content ?? '', 'utf-8')
+        const result = await uploadWorkspaceFile(
+          workspaceId,
+          userId,
+          fileBuffer,
+          fileName,
+          mimeType
+        )
+
+        logger.info('File created', {
+          fileId: result.id,
+          name: fileName,
+          size: fileBuffer.length,
+        })
+
+        return NextResponse.json({
+          success: true,
+          data: {
+            id: result.id,
+            name: result.name,
+            size: fileBuffer.length,
+            url: ensureAbsoluteUrl(result.url),
+          },
+        })
+      }
+
+      case 'append': {
+        const fileName = body.fileName as string | undefined
+        const content = body.content as string | undefined
+
+        if (!fileName) {
+          return NextResponse.json(
+            { success: false, error: 'fileName is required for append operation' },
+            { status: 400 }
+          )
+        }
+
+        if (!content && content !== '') {
+          return NextResponse.json(
+            { success: false, error: 'content is required for append operation' },
+            { status: 400 }
+          )
+        }
+
+        const existing = await getWorkspaceFileByName(workspaceId, fileName)
+        if (!existing) {
+          return NextResponse.json(
+            { success: false, error: `File not found: "${fileName}"` },
+            { status: 404 }
+          )
+        }
+
+        const existingBuffer = await downloadWorkspaceFile(existing)
+        const finalContent = existingBuffer.toString('utf-8') + content
+        const fileBuffer = Buffer.from(finalContent, 'utf-8')
+        await updateWorkspaceFileContent(workspaceId, existing.id, userId, fileBuffer)
+
+        logger.info('File appended', {
+          fileId: existing.id,
+          name: existing.name,
+          size: fileBuffer.length,
+        })
+
+        return NextResponse.json({
+          success: true,
+          data: {
+            id: existing.id,
+            name: existing.name,
+            size: fileBuffer.length,
+            url: ensureAbsoluteUrl(existing.path),
+          },
+        })
+      }
+
+      default:
+        return NextResponse.json(
+          { success: false, error: `Unknown operation: ${operation}. Supported: write, append` },
+          { status: 400 }
+        )
+    }
+  } catch (error) {
+    const message = error instanceof Error ? error.message : 'Unknown error'
+    logger.error('File operation failed', { operation, error: message })
+    return NextResponse.json({ success: false, error: message }, { status: 500 })
+  }
+}
diff --git a/apps/sim/blocks/blocks/file.ts b/apps/sim/blocks/blocks/file.ts
@@ -250,16 +250,27 @@ export const FileV2Block: BlockConfig<FileParserOutput> = {
 export const FileV3Block: BlockConfig<FileParserV3Output> = {
   type: 'file_v3',
   name: 'File',
-  description: 'Read and parse multiple files',
+  description: 'Read and write workspace files',
   longDescription:
-    'Upload files directly or import from external URLs to get UserFile objects for use in other blocks.',
+    'Read and parse files from uploads or URLs, write new workspace files, or append content to existing files.',
   docsLink: 'https://docs.sim.ai/tools/file',
   category: 'tools',
   integrationType: IntegrationType.FileStorage,
   tags: ['document-processing'],
   bgColor: '#40916C',
   icon: DocumentIcon,
   subBlocks: [
+    {
+      id: 'operation',
+      title: 'Operation',
+      type: 'dropdown' as SubBlockType,
+      options: [
+        { label: 'Read', id: 'file_parser_v3' },
+        { label: 'Write', id: 'file_write' },
+        { label: 'Append', id: 'file_append' },
+      ],
+      value: () => 'file_parser_v3',
+    },
     {
       id: 'file',
       title: 'Files',
@@ -270,7 +281,8 @@ export const FileV3Block: BlockConfig<FileParserV3Output> = {
       multiple: true,
       mode: 'basic',
       maxSize: 100,
-      required: true,
+      required: { field: 'operation', value: 'file_parser_v3' },
+      condition: { field: 'operation', value: 'file_parser_v3' },
     },
     {
       id: 'fileUrl',
@@ -279,22 +291,90 @@ export const FileV3Block: BlockConfig<FileParserV3Output> = {
       canonicalParamId: 'fileInput',
       placeholder: 'https://example.com/document.pdf',
       mode: 'advanced',
-      required: true,
+      required: { field: 'operation', value: 'file_parser_v3' },
+      condition: { field: 'operation', value: 'file_parser_v3' },
+    },
+    {
+      id: 'fileName',
+      title: 'File Name',
+      type: 'short-input' as SubBlockType,
+      placeholder: 'File name (e.g., data.csv)',
+      condition: { field: 'operation', value: 'file_write' },
+      required: { field: 'operation', value: 'file_write' },
+    },
+    {
+      id: 'content',
+      title: 'Content',
+      type: 'long-input' as SubBlockType,
+      placeholder: 'File content to write...',
+      condition: { field: 'operation', value: 'file_write' },
+      required: { field: 'operation', value: 'file_write' },
+    },
+    {
+      id: 'contentType',
+      title: 'Content Type',
+      type: 'short-input' as SubBlockType,
+      placeholder: 'text/plain (auto-detected from extension)',
+      condition: { field: 'operation', value: 'file_write' },
+      mode: 'advanced',
+    },
+    {
+      id: 'appendFileName',
+      title: 'File',
+      type: 'dropdown' as SubBlockType,
+      placeholder: 'Select a workspace file...',
+      condition: { field: 'operation', value: 'file_append' },
+      required: { field: 'operation', value: 'file_append' },
+      options: [],
+      fetchOptions: async () => {
+        const { useWorkflowRegistry } = await import('@/stores/workflows/registry/store')
+        const workspaceId = useWorkflowRegistry.getState().hydration.workspaceId
+        if (!workspaceId) return []
+        const response = await fetch(`/api/workspaces/${workspaceId}/files`)
+        const data = await response.json()
+        if (!data.success || !data.files) return []
+        return data.files.map((f: { name: string }) => ({ label: f.name, id: f.name }))
+      },
+    },
+    {
+      id: 'appendContent',
+      title: 'Content',
+      type: 'long-input' as SubBlockType,
+      placeholder: 'Content to append...',
+      condition: { field: 'operation', value: 'file_append' },
+      required: { field: 'operation', value: 'file_append' },
     },
   ],
   tools: {
-    access: ['file_parser_v3'],
+    access: ['file_parser_v3', 'file_write', 'file_append'],
     config: {
-      tool: () => 'file_parser_v3',
+      tool: (params) => params.operation || 'file_parser_v3',
       params: (params) => {
-        // Use canonical 'fileInput' param directly
+        const operation = params.operation || 'file_parser_v3'
+
+        if (operation === 'file_write') {
+          return {
+            fileName: params.fileName,
+            content: params.content,
+            contentType: params.contentType,
+            workspaceId: params._context?.workspaceId,
+          }
+        }
+
+        if (operation === 'file_append') {
+          return {
+            fileName: params.appendFileName,
+            content: params.appendContent,
+            workspaceId: params._context?.workspaceId,
+          }
+        }
+
         const fileInput = params.fileInput
         if (!fileInput) {
           logger.error('No file input provided')
           throw new Error('File input is required')
         }
 
-        // First, try to normalize as file objects (handles JSON strings from advanced mode)
         const normalizedFiles = normalizeFileInput(fileInput)
         if (normalizedFiles) {
           const filePaths = resolveFilePathsFromInput(normalizedFiles)
@@ -309,7 +389,6 @@ export const FileV3Block: BlockConfig<FileParserV3Output> = {
           }
         }
 
-        // If normalization fails, treat as direct URL string
         if (typeof fileInput === 'string' && fileInput.trim()) {
           return {
             filePath: fileInput.trim(),
@@ -326,17 +405,39 @@ export const FileV3Block: BlockConfig<FileParserV3Output> = {
     },
   },
   inputs: {
-    fileInput: { type: 'json', description: 'File input (canonical param)' },
-    fileType: { type: 'string', description: 'File type' },
+    operation: { type: 'string', description: 'Operation to perform (read, write, or append)' },
+    fileInput: { type: 'json', description: 'File input for read (canonical param)' },
+    fileType: { type: 'string', description: 'File type for read' },
+    fileName: { type: 'string', description: 'Name for a new file (write)' },
+    content: { type: 'string', description: 'File content to write' },
+    contentType: { type: 'string', description: 'MIME content type for write' },
+    appendFileName: { type: 'string', description: 'Name of existing file to append to' },
+    appendContent: { type: 'string', description: 'Content to append to file' },
   },
   outputs: {
     files: {
       type: 'file[]',
-      description: 'Parsed files as UserFile objects',
+      description: 'Parsed files as UserFile objects (read)',
     },
     combinedContent: {
       type: 'string',
-      description: 'All file contents merged into a single text string',
+      description: 'All file contents merged into a single text string (read)',
+    },
+    id: {
+      type: 'string',
+      description: 'File ID (write)',
+    },
+    name: {
+      type: 'string',
+      description: 'File name (write)',
+    },
+    size: {
+      type: 'number',
+      description: 'File size in bytes (write)',
+    },
+    url: {
+      type: 'string',
+      description: 'URL to access the file (write)',
     },
   },
 }