AI agents for Excel
A Monmo agent takes on your Excel work the way a spreadsheet specialist would. It builds workbooks from a description, writes and audits formulas, condenses thousands of rows into a pivot-style summary, repairs messy exports and draws the charts. New files come back as .xlsx in the Library. Changes to a workbook in your own account are shown to you before they are saved.
Updated 2026-11-13 · Free to start. Paid plans from $15 a month.
What agents do in Excel
Build a workbook from a description
Describe what you need, such as a quote calculator with volume discounts, and it builds the workbook: a price list, drop-down lists, formulas that point at named ranges and a check cell that flags a wrong total.
AskBuild a quote calculator for Fieldwork: price list on its own sheet, a drop-down to pick the product, 10 percent off above 50 units and tax on a separate line.
Write formulas for your version of Excel
Say what the cell should show and it writes the formula for the Excel you have: XLOOKUP in Microsoft 365, INDEX and MATCH where an older version needs them. A one-line note explains it to whoever maintains the file next.
AskIn column F, pull each customer's region from the Customers sheet by ID, and leave the cell blank when there is no match.
Check a workbook someone else built
It traces the formulas through a budget or forecast and lists what looks wrong: numbers typed over formulas, ranges that stop short of the last row, totals that do not add up and links to missing files.
AskAudit the Q3 budget workbook. List hard-coded numbers inside formulas and any range that misses the last rows.
Summarise rows into a pivot-style table
From 20,000 rows of orders it produces sales by month, region and product, with subtotals and each line's share of the total, on a new sheet. The source data is left exactly as it was.
AskSummarise the orders export by month and region, with each region's share of the total.
Repair a file exported from another system
It fixes what a .csv or an old .xls brings with it: numbers and dates stored as text, leading zeros lost from codes, merged header cells, blank rows and subtotals sitting inside the data. A notes sheet lists every change.
AskRepair the contacts export Jamie emailed me on Monday: one row per contact, real dates, postcodes with their leading zeros. Record each change on a Notes sheet.
Make charts that say one thing
A chart should answer one question. It plots revenue as columns and margin as a line where both matter, names each axis and its unit, drops gridlines and 3D effects, and puts the finding in the title.
AskChart monthly revenue against budget for this year. One chart, with the main finding as its title.
Refresh the same report every month
On the 2nd of each month it takes the new export, adds it to the workbook, extends the formulas and charts, checks the totals against last month and gives you the file with a note on what changed.
AskOn the 2nd of each month, add the new sales export to the report workbook and tell me what changed since last month.
How it connects
- 1Sign in once with your own Microsoft account and the agent can open the workbooks that account can open. A workbook it builds from nothing needs no connection; it arrives as a file in the Library.
- 2Excel belongs with the agents that work with numbers. A finance or data agent will use it daily; an agent that writes social posts has little use for it.
- 3Reading a workbook needs no approval, and neither does building a new file on the agent's own desktop. Changing or overwriting a workbook in your account always asks first, with the changes listed on one card.
More in Documents and files
Other apps of this kind that agents work in, each with its own page.
Watch it work
A sample replay with example data, sped up. Pause it, scrub through it, or take the mouse yourself. This sample shows a similar job in other tools; Excel is not on screen.
On screen
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Google Sheets
Pick a job. Watch it get done.
Your team. Connected to everything.
FY27 launch budget+FY27 launch budget
Expected case · prepared by Ren · sample data
Japan launch adds $474k from March.
Sea freight, six-week lead time.
Marketing peaks in launch month.
Sample replays with fictional data, sped up. Pause one, scrub through it, or take the mouse yourself.
Questions people ask
Can an AI agent build an Excel spreadsheet for me?
Yes. Describe the workbook in plain words and a Monmo agent builds it on its own desktop: sheets, formulas, formatting and charts. It checks that the totals agree before it hands the file over, and it saves the .xlsx in the Library for you to download and open in Excel.
Can an AI agent write Excel formulas?
Yes. The agent writes real Excel formulas, not pasted values, so the workbook recalculates when you change an input. Tell it which version of Excel you use, because some functions, such as XLOOKUP, are missing from older versions. It can then keep to functions your version supports and note any it avoided.
Can an AI agent edit a workbook that is already in OneDrive or SharePoint?
Yes, and it asks before it saves. The agent opens the workbook through your Microsoft connection, or in its own browser when the connection does not cover something, and shows the cells, sheets or formulas it wants to change. If you would rather keep the original untouched, ask for the result as a new file in the Library.
Can I trust the numbers in a spreadsheet built by an AI agent?
It works carefully, and it shows its checks so you can judge. The agent calculates with formulas instead of doing sums in its head, adds check rows that should equal zero and compares totals with the source. It tells you what it could not verify. For anything you will file or sign, review the workbook yourself.