Chat with a CSV

For a small CSV you’ll ask about once, you don’t need rho: attach it to a chat in Claude or ChatGPT and ask. That works well, and it’s the quickest way.

Where a chat runs out

• A big file doesn’t fit. Past a size, the upload is refused, or the model reads only part of the file and answers from that, often without saying so.
• It’s hard to check the numbers. You get a figure, but not what it was worked out from: which rows, which filter, whether a row was missed.
• The file lives in one chat. Next week, in a new chat or in another agent, you attach it again.
• Every export is a new file. With this month’s export and last month’s in two chats, there’s nothing to compare them by.
• The answer stays in the chat. To show a colleague, you copy it out.

What rho does instead

You upload the file to rho once, and your agent works with it over MCP, from Claude, ChatGPT, Cursor or any other MCP client.

• The agent queries the whole file, not a part of it. It reads each column’s type and a summary first, then runs SQL on every row. The rows don’t pass through the chat, so the file’s size doesn’t fill it up.
• A figure comes with a receipt. The agent links a page beside the number that shows the SQL it ran, the version of the file it read and the rows it answered. See Receipts.
• The file is still there. Any later chat, or another agent, finds it by its name and asks about it.
• A new export is a new version. Ask what changed since last month, or go back to an older one.
• Share it with a link. Make the table public and anyone with the link can open it, without signing in.

You: Which country had the highest average order value last quarter?

Claude: Sweden, at 1,240 kr over 312 orders. [Receipt]

How to start

1. Sign up. There’s no password.
2. Drop your file anywhere in the app. rho reads CSV, TSV, Excel, JSON, NDJSON and Parquet: see Upload a file.
3. Add rho to your agent, once: see the Quickstart.
4. Ask your agent about the table by its name, such as sales/orders.

An agent can also load a file itself from a URL, so the data never passes through the chat.

When something else fits better

For a small file you’ll ask about once, attach it to the chat. If you want to edit the rows by hand, a spreadsheet is the better tool.