📄 fix: Serve Stored Text for "Upload as Text" File Downloads (#14723)

* 📄 fix: Serve Stored Text for Text-Source File Downloads

"Upload as Text" attachments store extracted content in the DB with
source 'text'; OCR uploads persist the OCR strategy name (e.g.
'mistral_ocr') as a filepath placeholder since no backing file exists.
The download route resolved these records to the local strategy and
passed the placeholder to fs.createReadStream, which failed with
ENOENT — and the response was never ended after the stream error, so
the request hung until the client timed out.

Serve the stored text directly as a .txt download for text-source
files (re-fetched by _id, as getFiles excludes 'text' by default),
and end the response on stream errors: 500 without the download
headers before headers are sent, otherwise abort the truncated
response so clients detect the failure.

* fix: Preserve text-source preview semantics

* fix: Complete text-source download coverage

* fix: Tie text downloads to blob lifecycle

* fix: Isolate preview downloads and share text snapshots

* fix: Keep shared previews in share scope

* style: Sort text download imports

---------

Co-authored-by: Danny Avila <danny@librechat.ai>

client/src/components/Chat/Input/InFlightSteers.tsx

@@ -552,6 +552,7 @@ const InFlightSteer = memo(function InFlightSteer({
           fileId={selectedFile?.file_id}
           filePath={selectedFile?.filepath}
           fileType={selectedFile?.type ?? undefined}
+          fileSource={selectedFile?.source}
           fileSize={(selectedFile as TFile | null)?.bytes}
         />
       )}

client/src/components/Chat/Messages/Content/FilePreviewDialog.tsx

@@ -1,10 +1,11 @@
 import { useState, useEffect, useCallback, useMemo, useRef } from 'react';
 import copy from 'copy-to-clipboard';
-import { useRecoilValue } from 'recoil';
 import { Download } from 'lucide-react';
+import { useRecoilValue } from 'recoil';
 import { OGDialog, OGDialogContent, OGDialogTitle, OGDialogDescription } from '@librechat/client';
-import { useFileDownload, useSharedFileDownload } from '~/data-provider';
-import { logger, sortPagesByRelevance, triggerDownload } from '~/utils';
+import { getDownloadFilename, logger, sortPagesByRelevance, triggerDownload } from '~/utils';
+import { revokeDownloadURL, useFileDownload, useSharedFileDownload } from '~/data-provider';
+import { getFileExtension, getPreviewKind, shouldUseSharedFileDownload } from './preview';
 import CopyButton from '~/components/Messages/Content/CopyButton';
 import { useShareContext } from '~/Providers';
 import { useLocalize } from '~/hooks';
@@ -20,69 +21,10 @@ interface FilePreviewDialogProps {
   pages?: number[];
   pageRelevance?: Record<number, number>;
   fileType?: string;
+  fileSource?: string;
   fileSize?: number;
 }
 
-function getFileExtension(filename: string): string {
-  const dot = filename.lastIndexOf('.');
-  return dot > 0 ? filename.slice(dot + 1).toLowerCase() : '';
-}
-
-function canPreviewByMime(mime?: string): 'pdf' | 'text' | false {
-  if (!mime) {
-    return false;
-  }
-  if (mime.includes('pdf')) {
-    return 'pdf';
-  }
-  if (
-    mime.startsWith('text/') ||
-    mime.includes('json') ||
-    mime.includes('xml') ||
-    mime.includes('javascript') ||
-    mime.includes('typescript') ||
-    mime.includes('yaml') ||
-    mime.includes('csv')
-  ) {
-    return 'text';
-  }
-  return false;
-}
-
-function canPreviewByExt(filename: string): 'pdf' | 'text' | false {
-  const ext = getFileExtension(filename);
-  if (ext === 'pdf') {
-    return 'pdf';
-  }
-  const textExts = new Set([
-    'txt',
-    'md',
-    'csv',
-    'json',
-    'xml',
-    'yaml',
-    'yml',
-    'html',
-    'css',
-    'js',
-    'ts',
-    'jsx',
-    'tsx',
-    'py',
-    'rb',
-    'java',
-    'c',
-    'cpp',
-    'h',
-    'go',
-    'rs',
-    'sh',
-    'sql',
-    'log',
-  ]);
-  return textExts.has(ext) ? 'text' : false;
-}
-
 /** Formats bytes with unit suffix (differs from ~/utils/formatBytes which returns a raw number). */
 function formatBytes(bytes: number): string {
   if (bytes >= 1048576) {
@@ -130,22 +72,30 @@ export default function FilePreviewDialog({
   onOpenChange,
   fileName,
   fileId,
-  filePath,
   relevance,
   pages,
   pageRelevance,
   fileType,
+  fileSource,
   fileSize,
 }: FilePreviewDialogProps) {
   const localize = useLocalize();
   const user = useRecoilValue(store.user);
   const { shareId } = useShareContext();
+  // Preview reads revoke their blob after consumption, so they need a separate
+  // query identity from user-triggered downloads that may be in flight concurrently.
   const { refetch: downloadOwned } = useFileDownload(user?.id ?? '', fileId, { direct: false });
   const { refetch: downloadShared } = useSharedFileDownload(shareId, fileId);
-  // Use the share route only for snapshotted files (filepath rewritten to the
-  // share path); otherwise fall back to the owner route.
-  const useShared = !!shareId && (filePath?.startsWith('/api/share/') ?? false);
+  const { refetch: previewOwned } = useFileDownload(user?.id ?? '', fileId, {
+    direct: false,
+    purpose: 'preview',
+  });
+  const { refetch: previewShared } = useSharedFileDownload(shareId, fileId, 'preview');
+  // A shared viewer must stay inside the share-scoped authorization boundary;
+  // citation and retrieval previews do not carry a rewritten filepath signal.
+  const useShared = shouldUseSharedFileDownload(shareId, fileId);
   const downloadFile = useShared ? downloadShared : downloadOwned;
+  const previewFile = useShared ? previewShared : previewOwned;
 
   const [fileContent, setFileContent] = useState<string | null>(null);
   const [fileBlobUrl, setFileBlobUrl] = useState<string | null>(null);
@@ -154,7 +104,8 @@ export default function FilePreviewDialog({
   const [isCopied, setIsCopied] = useState(false);
   const loadingRef = useRef(false);
 
-  const previewKind = canPreviewByMime(fileType) || canPreviewByExt(fileName);
+  const previewKind = getPreviewKind(fileName, fileType, fileSource);
+  const downloadFilename = getDownloadFilename(fileName, fileId, fileSource);
 
   const cancelledRef = useRef(false);
 
@@ -168,16 +119,25 @@ export default function FilePreviewDialog({
     setPreviewError(false);
 
     try {
-      const result = await downloadFile();
-      if (cancelledRef.current || !result.data) {
+      const result = await previewFile();
+      if (!result.data) {
         if (!cancelledRef.current) {
           setPreviewError(true);
         }
         return;
       }
+      if (cancelledRef.current) {
+        revokeDownloadURL(result.data);
+        return;
+      }
 
-      const resp = await fetch(result.data);
-      const blob = await resp.blob();
+      let blob: Blob;
+      try {
+        const resp = await fetch(result.data);
+        blob = await resp.blob();
+      } finally {
+        revokeDownloadURL(result.data);
+      }
 
       if (cancelledRef.current) {
         return;
@@ -199,7 +159,7 @@ export default function FilePreviewDialog({
         setLoading(false);
       }
     }
-  }, [fileId, previewKind, downloadFile]);
+  }, [fileId, previewKind, previewFile]);
 
   const handleDownload = useCallback(async () => {
     if (!fileId) {
@@ -210,14 +170,14 @@ export default function FilePreviewDialog({
       if (!result.data) {
         return;
       }
-      triggerDownload(result.data, fileName);
+      triggerDownload(result.data, downloadFilename);
     } catch (err) {
       logger.error('[FilePreviewDialog] Download failed:', err);
     }
-  }, [downloadFile, fileId, fileName]);
+  }, [downloadFile, downloadFilename, fileId]);
 
   useEffect(() => {
-    if (open && previewKind && !fileContent && !fileBlobUrl) {
+    if (open && previewKind && fileContent === null && !fileBlobUrl) {
       loadPreview();
     }
   }, [open, previewKind, fileContent, fileBlobUrl, loadPreview]);
@@ -315,7 +275,7 @@ export default function FilePreviewDialog({
               className="h-[70vh] w-full rounded-lg border border-border-light"
             />
           )}
-          {fileContent && (
+          {fileContent !== null && (
             <>
               <div className="pointer-events-none sticky top-0 z-10 flex justify-end pr-1">
                 <CopyButton

client/src/components/Chat/Messages/Content/Files.tsx

@@ -48,6 +48,7 @@ const Files = ({ message }: { message?: TMessage }) => {
         fileId={selectedFile?.file_id}
         filePath={selectedFile?.filepath}
         fileType={selectedFile?.type ?? undefined}
+        fileSource={selectedFile?.source}
         fileSize={(selectedFile as TFile)?.bytes}
       />
     </>

client/src/components/Chat/Messages/Content/Parts/LogLink.tsx

@@ -1,8 +1,8 @@
 import React from 'react';
 import { useToastContext } from '@librechat/client';
 import { FileSources, sharedFileDownload } from 'librechat-data-provider';
+import { getDownloadFilename, isHttpDownloadTarget, triggerDownload } from '~/utils';
 import { useCodeOutputDownload, useFileDownload } from '~/data-provider';
-import { isHttpDownloadTarget, triggerDownload } from '~/utils';
 import { useShareContext } from '~/Providers';
 
 interface LogLinkProps {
@@ -37,6 +37,7 @@ export const isLocallyStoredSource = (source?: string): boolean => {
     FileSources.s3,
     FileSources.cloudfront,
     FileSources.azure_blob,
+    FileSources.text,
   ].includes(source as FileSources);
 };
 
@@ -53,6 +54,7 @@ export const useAttachmentLink = ({
   const useLocalDownload = isLocallyStoredSource(source) && !!file_id && !!user;
   const { refetch: downloadFromApi } = useFileDownload(user, file_id, { source });
   const { refetch: downloadFromUrl } = useCodeOutputDownload(href);
+  const downloadFilename = getDownloadFilename(filename, file_id, source);
 
   /**
    * Triggers the download and reports whether a file was actually
@@ -71,12 +73,12 @@ export const useAttachmentLink = ({
       // permission, not owner ACL). Non-snapshotted files fall through so the
       // original href / code-output path still works when snapshots are disabled.
       if (shareId && file_id && href.startsWith('/api/share/')) {
-        triggerDownload(sharedFileDownload(shareId, file_id), filename);
+        triggerDownload(sharedFileDownload(shareId, file_id), downloadFilename);
         return true;
       }
 
       if (!useLocalDownload && isHttpDownloadTarget(href)) {
-        triggerDownload(href, filename);
+        triggerDownload(href, downloadFilename);
         return true;
       }
 
@@ -89,7 +91,7 @@ export const useAttachmentLink = ({
         });
         return false;
       }
-      triggerDownload(stream.data, filename);
+      triggerDownload(stream.data, downloadFilename);
       return true;
     } catch (error) {
       console.error('Error downloading file:', error);

client/src/components/Chat/Messages/Content/Parts/SteerPart.tsx

@@ -133,6 +133,7 @@ const SteerPart = memo(function SteerPart({
           fileId={selectedFile?.file_id}
           filePath={selectedFile?.filepath}
           fileType={selectedFile?.type ?? undefined}
+          fileSource={selectedFile?.source}
           fileSize={(selectedFile as TFile | null)?.bytes}
         />
       )}

client/src/components/Chat/Messages/Content/Parts/__tests__/LogLink.test.tsx

@@ -23,6 +23,12 @@ jest.mock('~/Providers', () => ({
 }));
 
 jest.mock('~/utils', () => ({
+  getDownloadFilename: (filename: string, fileId?: string, source?: string) => {
+    const resolvedFilename = filename || fileId || 'download';
+    return source === 'text' && !resolvedFilename.toLowerCase().endsWith('.txt')
+      ? `${resolvedFilename}.txt`
+      : resolvedFilename;
+  },
   isHttpDownloadTarget: (target?: string | null) => /^https?:\/\//i.test(target ?? ''),
   triggerDownload: (...args: Parameters<typeof mockTriggerDownload>) =>
     mockTriggerDownload(...args),
@@ -129,4 +135,57 @@ describe('LogLink download routing', () => {
     expect(mockDownloadFromUrl).toHaveBeenCalledTimes(1);
     expect(mockDownloadFromApi).not.toHaveBeenCalled();
   });
+
+  it('uses a text filename for shared text-source downloads', async () => {
+    mockShareContext = { shareId: 'share-9' };
+    const filename = 'report.pdf';
+
+    render(
+      <LogLink
+        href="/api/share/share-9/files/file-1"
+        file_id="file-1"
+        filename={filename}
+        source={FileSources.text}
+      >
+        {filename}
+      </LogLink>,
+    );
+
+    fireEvent.click(screen.getByRole('link', { name: filename }));
+
+    await waitFor(() => {
+      expect(mockTriggerDownload).toHaveBeenCalledWith(
+        '/api/share/share-9/files/file-1/download',
+        'report.pdf.txt',
+      );
+    });
+  });
+
+  it('uses the authorized file route and a text filename for owned text-source files', async () => {
+    const filename = 'report.pdf';
+    mockDownloadFromApi.mockResolvedValue({ data: 'blob:https://app.example.com/text-file' });
+
+    render(
+      <LogLink
+        user="user-1"
+        file_id="file-1"
+        filename={filename}
+        source={FileSources.text}
+        href="mistral_ocr"
+      >
+        {filename}
+      </LogLink>,
+    );
+
+    fireEvent.click(screen.getByRole('link', { name: filename }));
+
+    await waitFor(() => {
+      expect(mockTriggerDownload).toHaveBeenCalledWith(
+        'blob:https://app.example.com/text-file',
+        'report.pdf.txt',
+      );
+    });
+    expect(mockDownloadFromApi).toHaveBeenCalledTimes(1);
+    expect(mockDownloadFromUrl).not.toHaveBeenCalled();
+  });
 });

client/src/components/Chat/Messages/Content/RetrievalCall.tsx

@@ -23,6 +23,7 @@ interface FileSource {
   pageRelevance: Record<number, number>;
   fileType?: string;
   fileBytes?: number;
+  fileSource?: string;
   metadata?: Record<string, unknown>;
 }
 
@@ -68,6 +69,7 @@ function extractFileSources(attachments?: TAttachment[]): FileSource[] {
           pageRelevance: source.pageRelevance || {},
           fileType: (meta?.fileType as string) || undefined,
           fileBytes: (meta?.fileBytes as number) || undefined,
+          fileSource: (meta?.storageType as string) || undefined,
           metadata: meta,
         });
       }
@@ -92,6 +94,7 @@ interface DisplayResult {
   pageRelevance?: Record<number, number>;
   fileType?: string;
   fileBytes?: number;
+  fileSource?: string;
 }
 
 interface FileMatch {
@@ -99,6 +102,7 @@ interface FileMatch {
   fileName: string;
   fileType?: string;
   fileBytes?: number;
+  fileSource?: string;
 }
 
 function normalizeFilename(filename: string): string {
@@ -142,6 +146,7 @@ function buildFileLookup(
       fileName: source.fileName,
       fileType: source.fileType,
       fileBytes: source.fileBytes,
+      fileSource: source.fileSource,
     });
   }
 
@@ -160,6 +165,7 @@ function buildFileLookup(
       fileName: file.filename,
       fileType: file.type ?? undefined,
       fileBytes: file.bytes,
+      fileSource: file.source ?? undefined,
     });
   }
 
@@ -181,6 +187,7 @@ function mergeRetrievalResults(
       pageRelevance: source.pageRelevance,
       fileType: source.fileType,
       fileBytes: source.fileBytes,
+      fileSource: source.fileSource,
     }));
   }
 
@@ -197,6 +204,7 @@ function mergeRetrievalResults(
       content: result.content,
       fileType: match?.fileType,
       fileBytes: match?.fileBytes,
+      fileSource: match?.fileSource,
     };
   });
 }
@@ -424,6 +432,7 @@ export default function RetrievalCall({
       pages: result.pages,
       pageRelevance: result.pageRelevance,
       fileType: result.fileType,
+      fileSource: result.fileSource,
     };
   }, [displayResults, previewIndex]);
 
@@ -522,6 +531,7 @@ export default function RetrievalCall({
         pages={previewData?.pages}
         pageRelevance={previewData?.pageRelevance}
         fileType={previewData?.fileType}
+        fileSource={previewData?.fileSource}
       />
     </div>
   );

client/src/components/Chat/Messages/Content/__tests__/FilePreviewDialog.test.ts

@@ -0,0 +1,25 @@
+import { FileSources } from 'librechat-data-provider';
+import { getPreviewKind, shouldUseSharedFileDownload } from '../preview';
+import { getDownloadFilename } from '~/utils/downloadFile';
+
+describe('FilePreviewDialog text-source behavior', () => {
+  it('previews extracted PDF content as text', () => {
+    expect(getPreviewKind('report.pdf', 'application/pdf', FileSources.text)).toBe('text');
+  });
+
+  it('downloads extracted content with a text extension', () => {
+    expect(getDownloadFilename('report.pdf', 'file-1', FileSources.text)).toBe('report.pdf.txt');
+    expect(getDownloadFilename('notes.txt', 'file-2', FileSources.text)).toBe('notes.txt');
+  });
+
+  it('preserves the original behavior for stored files', () => {
+    expect(getPreviewKind('report.pdf', 'application/pdf', FileSources.local)).toBe('pdf');
+    expect(getDownloadFilename('report.pdf', 'file-3', FileSources.local)).toBe('report.pdf');
+  });
+
+  it('routes any identified file through the share boundary in a shared view', () => {
+    expect(shouldUseSharedFileDownload('share-1', 'file-1')).toBe(true);
+    expect(shouldUseSharedFileDownload('share-1', undefined)).toBe(false);
+    expect(shouldUseSharedFileDownload(undefined, 'file-1')).toBe(false);
+  });
+});

client/src/components/Chat/Messages/Content/__tests__/RetrievalCall.test.tsx

@@ -82,9 +82,19 @@ jest.mock('~/data-provider', () => ({
 
 jest.mock('../FilePreviewDialog', () => ({
   __esModule: true,
-  default: ({ open, fileId, fileName }: { open: boolean; fileId?: string; fileName: string }) =>
+  default: ({
+    open,
+    fileId,
+    fileName,
+    fileSource,
+  }: {
+    open: boolean;
+    fileId?: string;
+    fileName: string;
+    fileSource?: string;
+  }) =>
     open ? (
-      <div data-testid="file-preview-dialog" data-file-id={fileId}>
+      <div data-testid="file-preview-dialog" data-file-id={fileId} data-file-source={fileSource}>
         {fileName}
       </div>
     ) : null,
@@ -220,6 +230,7 @@ describe('RetrievalCall - file preview resolution', () => {
           filename: 'Tutorial Imazing.pdf',
           bytes: 2048,
           type: 'application/pdf',
+          source: 'text',
         },
       ],
     });
@@ -235,6 +246,7 @@ describe('RetrievalCall - file preview resolution', () => {
     fireEvent.click(screen.getByRole('button', { name: 'Preview: Tutorial Imazing.pdf' }));
 
     expect(screen.getByTestId('file-preview-dialog')).toHaveAttribute('data-file-id', 'file-123');
+    expect(screen.getByTestId('file-preview-dialog')).toHaveAttribute('data-file-source', 'text');
   });
 
   it('keeps multiple parsed results clickable when only one attachment source is available', () => {

client/src/components/Chat/Messages/Content/preview.ts

@@ -0,0 +1,79 @@
+import { FileSources } from 'librechat-data-provider';
+
+type PreviewKind = 'pdf' | 'text' | false;
+
+const TEXT_EXTENSIONS = new Set([
+  'txt',
+  'md',
+  'csv',
+  'json',
+  'xml',
+  'yaml',
+  'yml',
+  'html',
+  'css',
+  'js',
+  'ts',
+  'jsx',
+  'tsx',
+  'py',
+  'rb',
+  'java',
+  'c',
+  'cpp',
+  'h',
+  'go',
+  'rs',
+  'sh',
+  'sql',
+  'log',
+]);
+
+export function getFileExtension(filename: string): string {
+  const dot = filename.lastIndexOf('.');
+  return dot > 0 ? filename.slice(dot + 1).toLowerCase() : '';
+}
+
+export function shouldUseSharedFileDownload(shareId?: string, fileId?: string): boolean {
+  return !!shareId && !!fileId;
+}
+
+function getPreviewKindByMime(mime?: string): PreviewKind {
+  if (!mime) {
+    return false;
+  }
+  if (mime.includes('pdf')) {
+    return 'pdf';
+  }
+  if (
+    mime.startsWith('text/') ||
+    mime.includes('json') ||
+    mime.includes('xml') ||
+    mime.includes('javascript') ||
+    mime.includes('typescript') ||
+    mime.includes('yaml') ||
+    mime.includes('csv')
+  ) {
+    return 'text';
+  }
+  return false;
+}
+
+function getPreviewKindByExtension(filename: string): PreviewKind {
+  const extension = getFileExtension(filename);
+  if (extension === 'pdf') {
+    return 'pdf';
+  }
+  return TEXT_EXTENSIONS.has(extension) ? 'text' : false;
+}
+
+export function getPreviewKind(
+  fileName: string,
+  fileType?: string,
+  fileSource?: string,
+): PreviewKind {
+  if (fileSource === FileSources.text) {
+    return 'text';
+  }
+  return getPreviewKindByMime(fileType) || getPreviewKindByExtension(fileName);
+}

client/src/components/Web/Citation.tsx

@@ -11,6 +11,7 @@ import { useLocalize } from '~/hooks';
 interface FileCitationMetadata {
   fileBytes?: number;
   fileType?: string;
+  storageType?: string;
 }
 
 interface FileCitationSource {
@@ -282,6 +283,7 @@ export function CompositeCitation(props: CompositeCitationProps) {
           pages={filePages}
           pageRelevance={filePageRelevance}
           fileType={fileMeta?.fileType}
+          fileSource={fileMeta?.storageType}
           fileSize={fileMeta?.fileBytes}
         />
       )}
@@ -358,6 +360,7 @@ export function Citation(props: CitationComponentProps) {
           pages={filePages}
           pageRelevance={filePageRelevance}
           fileType={fileMeta?.fileType}
+          fileSource={fileMeta?.storageType}
           fileSize={fileMeta?.fileBytes}
         />
       )}

client/src/components/Web/__tests__/Citation.test.tsx

@@ -29,9 +29,19 @@ jest.mock('~/hooks', () => ({
 
 jest.mock('~/components/Chat/Messages/Content/FilePreviewDialog', () => ({
   __esModule: true,
-  default: ({ open, fileId, fileName }: { open: boolean; fileId?: string; fileName: string }) =>
+  default: ({
+    open,
+    fileId,
+    fileName,
+    fileSource,
+  }: {
+    open: boolean;
+    fileId?: string;
+    fileName: string;
+    fileSource?: string;
+  }) =>
     open ? (
-      <div data-testid="file-preview-dialog" data-file-id={fileId}>
+      <div data-testid="file-preview-dialog" data-file-id={fileId} data-file-source={fileSource}>
         {fileName}
       </div>
     ) : null,
@@ -76,6 +86,7 @@ describe('Citation', () => {
             metadata: {
               fileBytes: 2048,
               fileType: 'application/pdf',
+              storageType: 'text',
             },
             pageRelevance: { 1: 0.92 },
             pages: [1],
@@ -107,6 +118,7 @@ describe('Citation', () => {
     fireEvent.click(fileButton);
 
     expect(screen.getByTestId('file-preview-dialog')).toHaveAttribute('data-file-id', 'file-123');
+    expect(screen.getByTestId('file-preview-dialog')).toHaveAttribute('data-file-source', 'text');
   });
 
   it('keeps standalone web citations as links', () => {

client/src/data-provider/Files/queries.ts

@@ -3,8 +3,13 @@ import { useQuery, useQueryClient } from '@tanstack/react-query';
 import { FileSources, QueryKeys, DynamicQueryKeys, dataService } from 'librechat-data-provider';
 import type { QueryObserverResult, UseQueryOptions } from '@tanstack/react-query';
 import type t from 'librechat-data-provider';
+import {
+  addFileToCache,
+  getDownloadFilename,
+  registerDownloadFilename,
+  unregisterDownloadFilename,
+} from '~/utils';
 import { isEphemeralAgent } from '~/common';
-import { addFileToCache } from '~/utils';
 import store from '~/store';
 
 export const useGetFiles = <TData = t.TFile[] | boolean>(
@@ -56,6 +61,7 @@ export const useGetFileConfig = <TData = t.TFileConfig>(
 type FileDownloadOptions = {
   source?: string | null;
   direct?: boolean;
+  purpose?: 'download' | 'preview';
 };
 
 export const isDirectDownloadSource = (source?: string | null): boolean =>
@@ -65,6 +71,7 @@ export const revokeDownloadURL = (url?: string | null): void => {
   if (!url?.startsWith('blob:')) {
     return;
   }
+  unregisterDownloadFilename(url);
   window.URL.revokeObjectURL(url);
 };
 
@@ -75,7 +82,13 @@ export const useFileDownload = (
 ): QueryObserverResult<string> => {
   const queryClient = useQueryClient();
   return useQuery(
-    [QueryKeys.fileDownload, file_id, options.source ?? '', options.direct ?? true],
+    [
+      QueryKeys.fileDownload,
+      file_id,
+      options.source ?? '',
+      options.direct ?? true,
+      options.purpose ?? 'download',
+    ],
     async () => {
       if (!userId || !file_id) {
         console.warn('No user ID provided for file download');
@@ -104,6 +117,10 @@ export const useFileDownload = (
           return downloadURL;
         }
 
+        registerDownloadFilename(
+          downloadURL,
+          getDownloadFilename(metadata.filename, metadata.file_id, metadata.source),
+        );
         addFileToCache(queryClient, metadata);
       } catch (e) {
         console.error('Error parsing file metadata, skipped updating file query cache', e);
@@ -126,9 +143,10 @@ export const useFileDownload = (
 export const useSharedFileDownload = (
   shareId?: string,
   file_id?: string,
+  purpose: 'download' | 'preview' = 'download',
 ): QueryObserverResult<string> => {
   return useQuery(
-    [QueryKeys.fileDownload, 'share', shareId ?? '', file_id ?? ''],
+    [QueryKeys.fileDownload, 'share', shareId ?? '', file_id ?? '', purpose],
     async () => {
       if (!shareId || !file_id) {
         return;

client/src/utils/__tests__/downloadFile.test.ts

@@ -1,4 +1,12 @@
-import { getCodeBlockFilename, isHttpDownloadTarget, triggerDownload } from '../downloadFile';
+import { FileSources } from 'librechat-data-provider';
+import {
+  getCodeBlockFilename,
+  getDownloadFilename,
+  isHttpDownloadTarget,
+  registerDownloadFilename,
+  triggerDownload,
+  unregisterDownloadFilename,
+} from '../downloadFile';
 
 describe('downloadFile utilities', () => {
   let clickSpy: jest.SpyInstance;
@@ -68,6 +76,50 @@ describe('downloadFile utilities', () => {
     jest.advanceTimersByTime(1000);
     expect(revokeSpy).toHaveBeenCalledWith('blob:https://app.example.com/download-id');
   });
+
+  it('uses registered response metadata to name blob downloads', () => {
+    const target = 'blob:https://app.example.com/text-download';
+    registerDownloadFilename(target, 'report.pdf.txt');
+
+    triggerDownload(target, 'report.pdf');
+
+    expect(appendedLink?.download).toBe('report.pdf.txt');
+  });
+
+  it('keeps registered names available for concurrent blob downloads', () => {
+    const target = 'blob:https://app.example.com/concurrent-download';
+    registerDownloadFilename(target, 'report.pdf.txt');
+
+    triggerDownload(target, 'report.pdf');
+    expect(appendedLink?.download).toBe('report.pdf.txt');
+
+    triggerDownload(target, 'report.pdf');
+    expect(appendedLink?.download).toBe('report.pdf.txt');
+  });
+
+  it('clears registered names when blob URLs are released', () => {
+    const target = 'blob:https://app.example.com/released-download';
+    registerDownloadFilename(target, 'report.pdf.txt');
+    unregisterDownloadFilename(target);
+
+    triggerDownload(target, 'report.pdf');
+
+    expect(appendedLink?.download).toBe('report.pdf');
+  });
+});
+
+describe('getDownloadFilename', () => {
+  it('adds a text extension for text-source files', () => {
+    expect(getDownloadFilename('report.pdf', 'file-1', FileSources.text)).toBe('report.pdf.txt');
+  });
+
+  it('recognizes existing text extensions case-insensitively', () => {
+    expect(getDownloadFilename('NOTES.TXT', 'file-2', FileSources.text)).toBe('NOTES.TXT');
+  });
+
+  it('preserves filenames for other storage sources', () => {
+    expect(getDownloadFilename('report.pdf', 'file-3', FileSources.local)).toBe('report.pdf');
+  });
 });
 
 describe('getCodeBlockFilename', () => {

client/src/utils/downloadFile.ts

@@ -1,6 +1,32 @@
+import { FileSources } from 'librechat-data-provider';
+
+const blobDownloadFilenames = new Map<string, string>();
+
 export const isHttpDownloadTarget = (target?: string | null): boolean =>
   /^https?:\/\//i.test(target ?? '');
 
+export function getDownloadFilename(
+  fileName: string,
+  fileId?: string,
+  fileSource?: string | null,
+): string {
+  const filename = fileName || fileId || 'download';
+  if (fileSource !== FileSources.text || filename.toLowerCase().endsWith('.txt')) {
+    return filename;
+  }
+  return `${filename}.txt`;
+}
+
+export function registerDownloadFilename(target: string, filename: string): void {
+  if (target.startsWith('blob:')) {
+    blobDownloadFilenames.set(target, filename);
+  }
+}
+
+export function unregisterDownloadFilename(target: string): void {
+  blobDownloadFilenames.delete(target);
+}
+
 /**
  * Maps a fenced-block language hint to a file extension. Used to name
  * downloads of chat code blocks (`code.<ext>`). Only languages whose common
@@ -63,11 +89,14 @@ export function triggerDownload(target: string, filename: string): void {
   const isBlob = target.startsWith('blob:');
   const link = document.createElement('a');
   link.href = target;
-  link.setAttribute('download', filename);
+  link.setAttribute('download', blobDownloadFilenames.get(target) ?? filename);
   document.body.appendChild(link);
   link.click();
   document.body.removeChild(link);
   if (isBlob) {
-    setTimeout(() => URL.revokeObjectURL(target), 1000);
+    setTimeout(() => {
+      unregisterDownloadFilename(target);
+      URL.revokeObjectURL(target);
+    }, 1000);
   }
 }