danny-avila/LibreChat · warning · Error

File type ${file.mimetype} is not supported for text parsing

Error message

File type ${file.mimetype} is not supported for text parsing.

What it means

Thrown at the end of the MIME-type routing chain when the uploaded file's MIME matches none of: OCR-supported, STT-supported, or text-supported MIME lists (and `shouldUseConfiguredText` is false). The server has no configured handler for that MIME type, so it refuses text extraction rather than guessing.

Source

Thrown at api/server/services/Files/process.js:881

    const shouldUseSTT = fileConfig.checkType(
      file.mimetype,
      fileConfig.stt?.supportedMimeTypes || [],
    );

    if (shouldUseSTT) {
      const sttService = await STTService.getInstance();
      const { text, bytes } = await processAudioFile({ req, file, sttService });
      return await createTextFile({ text, bytes });
    }

    const shouldUseText = fileConfig.checkType(
      file.mimetype,
      fileConfig.text?.supportedMimeTypes || [],
    );

    if (!shouldUseText) {
      throw new Error(`File type ${file.mimetype} is not supported for text parsing.`);
    }

    /**
     * A document type the admin routed to configured text extraction: prefer RAG `/text`, but fall
     * back to the built-in document parser (not raw native text) when RAG is unavailable, so a
     * transient outage doesn't degrade a docx/pdf to unreadable bytes. Only the RAG extraction is
     * inside the fallback catch: a downstream persistence failure (size guard, DB, agent-resource
     * mutation) must surface as itself, not trigger a second extraction attempt.
     */
    if (shouldUseConfiguredText) {
      let configuredText;
      try {
        configuredText = await parseText({ req, file, file_id, allowNativeFallback: false });
      } catch (err) {
        logger.warn(
          `[processAgentFileUpload] Configured RAG text extraction unavailable for "${file.originalname}", using built-in document parser:`,
          err,
        );

View on GitHub (pinned to 5ff282f900)

Solutions

1. Add the MIME type to the appropriate `supportedMimeTypes` array in fileConfig (text/OCR/STT) via admin settings.
2. Upload a supported format instead (convert the file to PDF/DOCX/TXT).
3. Verify the actual MIME with `file --mime-type` — Multer may have sniffed from extension and gotten it wrong.
4. If the type should never be parsed, suppress the upload affordance in the UI for that type.

Example fix

// config: enable CSV and Markdown text extraction
fileConfig: {
  text: { supportedMimeTypes: [
    'text/plain', 'text/markdown', 'text/csv',
    'application/pdf', 'application/vnd.openxmlformats...'
  ] }
}

function isSupportedMime(file, fileConfig) {
  const lists = [
    fileConfig.ocr?.supportedMimeTypes || [],
    fileConfig.stt?.supportedMimeTypes || [],
    fileConfig.text?.supportedMimeTypes || [],
  ];
  return lists.some(l => l.includes(file.mimetype));
}

try { await processAgentFileUpload(params); }
catch (e) {
  if (/is not supported for text parsing/.test(e.message)) return res.status(415).json({ error: e.message });
  throw e;
}

When it happens

Trigger: A file whose MIME is not in any of the admin-configured `supportedMimeTypes` arrays for OCR, STT, or text — e.g., a `.zip`, `.exe`, `.csv` not enabled for text, or an unusual MIME like `application/x-foo`. Also a real document type the admin simply didn't whitelist.

Common situations: Admin enabled PDF/DOCX but not TXT/CSV/MD; user uploads a binary archive expecting extraction; MIME sniffed incorrectly so a supported type is misclassified; a new file type not yet in the config.

Related errors

• Image uploads are not supported for file search tool resourc
• [${req.baseUrl}] Endpoint is required
• Text is required
• Error uploading file: ${result.message}
• Unexpected batch upload response: ${JSON.stringify(result).s

AI-assisted analysis of danny-avila/LibreChat@5ff282f900 (2026-08-12). Data as JSON: /api/errors/db6e2e564101141c. Report an issue: GitHub.