Deckary Excel documentation

Deckary's Excel AI agent works inside the workbook that is open in Microsoft Excel. It can inspect sheets and ranges, write formulas and values, apply native formatting, add worksheets, and audit formulas. Workbook reads and writes execute locally through the Deckary Office add-in; the web service coordinates the model run.

Choose an Excel workflow#

What the agent can change#

The agent can write values, formulas, notes, number formats, borders, and styles; fill a pattern across a range; size, insert, and delete rows and columns; merge cells; add conditional formats and data validation; create or change tables, charts, and defined names; and create, rename, color, freeze, hide, move, or delete worksheets. Before it plans a change, it reads the workbook outline and cell windows, and it can inspect exact formatting and objects. Each change is one program for one worksheet, the same one an external agent uses through live Excel MCP.

Generated output uses native Excel structures. A formula is written as a formula, a note as a cell note, and formatting as workbook formatting rather than a screenshot or detached table.

Workbook protection and verification#

Deckary binds each run to the active workbook identity. A planned mutation cannot cross into a different workbook. Writes require a runtime-issued authorization and host-observed result before the agent can claim completion.

When a change would replace non-empty cells or delete rows, columns, tables, charts, names, or worksheets, the agent follows Deckary's destructive-edit approval path. The approval is tied to the workbook version the agent checked; if the workbook changes before the retry, Deckary asks the agent to read it again instead of overwriting the newer values.

The standalone Formula Tracer is a separate visual dependency tool. Formula auditing in the AI agent is covered in Audit formulas.