Nimbalyst includes a built-in spreadsheet editor for CSV and TSV files. Open any .csv or .tsv file and it automatically displays in a familiar spreadsheet interface.

See the spreadsheets feature page for how agents work with tabular data in a project.

If you want a calculation-first document instead of a row-and-column data grid, use a Calc Sheet with the .calc.md extension.

CSV Spreadsheet Editor

The editor works like a familiar spreadsheet. You can:

Edit, add, and delete cells, rows, and columns
Cut, copy, paste, undo, and redo ranges
Write formulas with cell references and see results update live
Find and replace values, sort columns, and filter rows
Freeze rows and columns
Set typed columns for numbers, currency, percentages, dates, checkboxes, links, and tracker items
Format selected cells with text styles, colors, and alignment

Click View Source in the toolbar to toggle between the spreadsheet view and raw CSV text.

Formatting, column types, filters, and frozen panes need metadata that CSV itself cannot represent. Depending on the project setting, Nimbalyst stores that metadata in an inline CSV comment or a separate .csvmeta sidecar file. The cell values and formulas remain in the CSV or TSV.

Using Coding Agents with CSV Files

Your coding agent can read and modify your CSV files directly. This is powerful for data tasks that would be tedious to do manually.

Data Cleaning

"Remove all duplicate rows from data.csv"
"Fix the date format in the 'created_at' column to YYYY-MM-DD"
"Trim whitespace from all cells in customers.csv"

Data Transformation

"Add a new column that calculates the total from price and quantity"
"Split the 'full_name' column into 'first_name' and 'last_name'"
"Convert all country codes to full country names"

Analysis & Filtering

"Remove all rows where status is 'cancelled'"
"Sort by revenue descending and keep only the top 100"
"Find and flag any rows with missing email addresses"

Bulk Operations

"Add 'USD' prefix to all values in the currency column"
"Replace all instances of 'N/A' with empty cells"
"Normalize phone numbers to +1-XXX-XXX-XXXX format"

Generating Data

"Create a CSV with 50 sample customer records for testing"
"Add a header row with appropriate column names"

How It Works

When you ask your coding agent to modify a CSV file, it reads the file, makes the changes programmatically, and writes the updated content back. The spreadsheet editor will automatically refresh to show your changes.

AI Changes as Red / Green Diff

Agent edits appear as a red/green diff. The grid stays read-only until you accept or reject the pending change, which prevents a manual cell edit from being mixed into the review.