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Using OpenIntern

Excel

In Excel, OpenIntern builds and repairs workbooks with live formulas, cleans data, formats to your house style and explains what a workbook is doing. It reads the workbook you have open, makes its changes through checked operations and verifies the result before it finishes.

What you can ask for

Models and analysis

Three-statement models, DCF, LBO, variance analysis, peer comparisons with calendarised fiscal periods, loan schedules and forecasts. It writes formulas, not pasted results, and keeps assumptions on their own labelled inputs.

  • "Build a three-statement model from this trial balance, with forecasts on a separate assumptions tab."
  • "Build a store results summary for 2025 vs 2024 with revenue change, % change, operating margin for each year and a total row. Format it cleanly and add a chart of 2025 revenue by store."
  • "What if Riverside's 2025 revenue were 1,900,000? Show the effect on total revenue and total margin."

A what-if reports the before, after and change for every output it is watching, and the change is recorded like any other, so you can undo it.

Cleaning data

Duplicates, numbers stored as text, dates in mixed formats, inconsistent names and categories, messy exports.

  • "Clean up this CRM export."
  • "One row per order, trimmed names in proper case, dates as real dates, amounts as numbers, duplicates removed."

Rows are deleted only after you confirm, and the answer says which rows were duplicates.

Formatting and structure

Headers, number formats, input colouring, conditional formatting, charts, tables, pivot tables, data validation and dropdowns, freeze panes and print setup.

  • "Summarise revenue by store with a pivot table on a new sheet, and sort stores by total revenue."
  • "Add a status column that says Above or Below target with a formula, and highlight Below in red."

Explaining and fixing

It traces #REF!, #VALUE!, #DIV/0!, #N/A, #NAME? and circular references back to their cause and proposes a fix, and explains a cell from the cells it depends on.

  • "Why doesn't this total match the detail?"
  • "Check this workbook for errors and explain the operating margin formula for Riverside."

In Chat only mode it answers questions like these without changing anything.

Bringing data in

  • Attachments: CSV, XLSX, PDF, DOCX and PPTX files you attach with +. Imported numbers keep a note of where they came from.
  • Web search on your own Exa key. See Connectors.
  • SEC filings (local software): company facts from SEC XBRL data, with the fiscal periods they cover.
  • Python for computation (local software on a Mac): for regressions, statistics, scenario runs and IRR or NPV checks, OpenIntern can run Python in an isolated sandbox. The sandbox never writes to the workbook; anything worth keeping is written back as an ordinary, recorded change, and anything one Excel formula can do stays a live formula.

How it checks its work

Before it says a task is done, OpenIntern reads the live workbook back and checks what it built:

  • expected values in the cells it was asked to produce;
  • no error values in the ranges it built;
  • the same formula all the way down a column and across every period;
  • totals that tie, a balance sheet that balances, and sums, counts and cross-sheet figures that agree;
  • periods and units that match.

The answer lists the checks that passed. A task also has a review pass that reads the result back against your request before it can finish.

Your house style

Under More (⋯) > Instructions, the Conventions section holds the formatting rules a formatting task follows: currency, negatives, decimals, thousands separator, percent decimals, header style, fill and text colour, input colour, bold totals, font name and size, date format, hidden gridlines and a frozen header row. Reset to defaults puts them back.

What it won't do

  • Invent figures. If it cannot source a number, it says so rather than making one up. Missing inputs stay visibly missing.
  • Present a forecast as fact. Forecast assumptions are labelled as assumptions and are never attributed to the company.
  • Paste results where a formula belongs. Calculations stay live.
  • Delete without asking. Deleting rows, columns or sheets, and overwriting content it did not write, need your confirmation, unless you have turned on Bypass permissions in the local software.
  • Take orders from the workbook. Text in a cell, a comment or an attachment is treated as data. It cannot grant permissions or change what OpenIntern may do.

When it meets a formula or object it cannot handle, it says so in the answer instead of guessing. Some changes cannot be undone, such as deleting a sheet; see Undo.

Working across apps

In the local software, one conversation follows you between the Excel, PowerPoint and Word panes, so you can build the numbers in a workbook and then ask for the deck and the memo. Figures written into a deck or memo from workbook cells stay linked and can be refreshed when the numbers change. More (⋯) > Open documents lists the documents the server can see and the links between them.

The store add-in works one document at a time: each window has its own session and cannot read a workbook open in another window. Paste or describe the figures you need, or attach a copy of the workbook.