FeaturesFile Uploads

File Uploads

You can attach files directly to your messages — documents, spreadsheets, images, and more. Cumulus reads and analyzes the content so you can ask questions about it, get summaries, and extract insights.


How to attach a file

There are two ways:

Option 1 — Drag and drop Drag any file from your computer and drop it onto the chat area. The file is automatically attached.

Option 2 — Click the + button Click the + icon to the left of the message input to open a file picker.


Supported file types

FormatExtensions
Documents.pdf, .docx, .txt, .md
Spreadsheets.csv, .xlsx
Data.json, .xml
Images.png, .jpg, .gif, .webp

Limits

LimitValue
Per file50 MB
Files per chat session10 assets
Sources per project20 sources

File status indicators

After attaching a file, a chip appears in the input area showing the file’s status:

StatusWhat it means
⟳ SpinnerFile is uploading
✓ CheckmarkReady to send with your message
⚠ TriangleUpload failed — try again

You can remove an attached file by clicking the X on its chip before sending.


What happens after upload

Once you send a message with a file attached, Cumulus begins ingesting it. Large documents move through a progressive pipeline:

Extract

The document’s text and structure are extracted from the raw file.

Chunk

The content is split into segments sized for AI retrieval.

Embed

Each chunk is converted into a vector embedding and indexed for search.

Ready

The file is fully indexed. Cumulus notifies you in chat when it’s ready to query — for long documents, expect a short wait while this completes.

For large documents, be specific about what you want. “Summarize section 3” is faster and more accurate than “summarize everything.”


What to ask once a file is ready

  • Summarize — “Summarize the key points from this document”
  • Analyze data — “What are the trends in this spreadsheet?”
  • Answer questions — “Does this PDF mention anything about the refund policy?”
  • Extract information — “List all action items from this meeting notes document”
  • Compare — “Compare the content of these two files”

Citations

Once a file is ingested, Cumulus cites it in its answers — linking the specific passage or table it drew from. See Citations for how citation links work and how to navigate them.


For SharePoint or Google Drive documents, you don’t need to upload files manually — they’re available directly through the relevant integration.