Excel MCP Server

An open-source Model Context Protocol (MCP) server that lets Claude, Cursor, VS Code Copilot, Codex and other AI clients create, read and edit Excel files: charts, PivotTables, formulas, tables and more. It is built on openpyxl, needs no Microsoft Excel, and runs on Windows, macOS and Linux.

Install and try it at excelmcpserver.com, or see Quick start below.

Features

Charts and PivotTables

• Create Excel charts with AI: column, bar, line, area, pie, doughnut, radar, scatter and bubble, with combos, secondary axes, trendlines and error bars
• The Excel 2016 chart types: waterfall, histogram, Pareto, box and whisker, treemap, sunburst and funnel
• Real PivotTables that Excel refreshes (grouping, calculated fields, "show values as", layouts, filters), plus slicers and timelines for PivotTables and tables
• Sparklines (line, column, win/loss)

Formulas and dynamic arrays

• Formulas are calculated without Excel by a built-in engine (about 260 functions, checked against more than 2,500 formulas recorded from real Excel), so read_range returns values for files that were never opened in Excel
• Dynamic arrays (FILTER, SORT, UNIQUE, SEQUENCE, LET) are stored as Excel stores them and spill into the cells next to them

Data, tables and rules

• Read and write cells, dates and hyperlinks; tables with totals rows and calculated columns
• Conditional formatting (scales, data bars, icon sets, top/bottom, duplicates, text, dates), data validation (dropdowns, limits, input messages)
• Sort, filter (with criteria), find and replace, remove duplicates, text to columns, fill series, paste special
• Fonts, fills, borders, number formats, merged cells, frozen panes, grouping, print setup, sheet protection, images, notes and defined names. Inserting or deleting rows and columns updates every reference, as in Excel

Large files

• Reads stream the workbook and return pages, so memory stays flat on sheets with hundreds of thousands of rows; every call is bounded by size and cell limits

Macros (opt-in)

• Read the VBA code in .xlsm files. Writing VBA is off unless you start the server with --allow-vba-write; the server never runs macros

Safe by design

• Optional folder confinement, a formula safety check, read-only mode, localhost-only HTTP by default, and atomic saves that never leave a half-written file

Works with .xlsx, .xlsm (macros are preserved), .xltx and .xltm files. Existing threaded comments, shapes, form controls and other content the tools cannot edit are kept as they are.

Quick start

You need uv. Every client runs the server with uvx excel-mcp-server stdio; replace /path/to/workbooks with the folder the server may use. excelmcpserver.com has the same steps with copy buttons and one-click install links for Cursor and VS Code.

Claude Desktop (Chat): download excel-mcp-server.mcpb from the latest release and open it. Claude asks which folder the server may use.

Claude Code (the CLI, and the Code tab in Claude Desktop):

claude mcp add excel --scope user -- uvx excel-mcp-server stdio --allow-dir /path/to/workbooks

Cursor (~/.cursor/mcp.json), and most clients that use an mcpServers config:

{
  "mcpServers": {
    "excel": {
      "command": "uvx",
      "args": ["excel-mcp-server", "stdio", "--allow-dir", "/path/to/workbooks"]
    }
  }
}

VS Code with GitHub Copilot (.vscode/mcp.json, note the servers key):

{
  "servers": {
    "excel": {
      "type": "stdio",
      "command": "uvx",
      "args": ["excel-mcp-server", "stdio", "--allow-dir", "${workspaceFolder}"]
    }
  }
}

OpenAI Codex, Gemini CLI, Devin Desktop, and Claude Desktop without the bundle

OpenAI Codex (CLI, IDE extension and app):

codex mcp add excel -- uvx excel-mcp-server stdio --allow-dir /path/to/workbooks

Gemini CLI:

gemini mcp add -s user excel uvx excel-mcp-server stdio --allow-dir /path/to/workbooks

Devin Desktop:

devin mcp add -s user excel -- uvx excel-mcp-server stdio --allow-dir /path/to/workbooks

Claude Desktop, manual setup: open Settings, Developer, Edit Config, add the mcpServers JSON above to claude_desktop_config.json, and restart Claude.

Desktop apps often cannot find uvx, because they do not see your shell's PATH (common on macOS). Use its full path instead, which which uvx prints.

Choosing which files it can use

With --allow-dir DIR, the server only opens workbooks inside DIR (subfolders included) and relative paths such as reports/q1.xlsx start there. Repeat the flag to allow several folders, or set EXCEL_FILES_PATH (separate folders with : on macOS/Linux and ; on Windows).

Without --allow-dir, any absolute path to an Excel file works. In every mode the server only touches Excel files and never silently overwrites an existing workbook.

Remote use (Streamable HTTP)

uvx excel-mcp-server streamable-http --allow-dir /srv/workbooks

Clients connect to http://127.0.0.1:8017/mcp. Workbooks live in the --allow-dir folder (default ./excel_files), and export_workbook / import_workbook move files between the server and the client.

The server listens on localhost only. To accept other machines, set a token and a host:

EXCEL_MCP_AUTH_TOKEN=change-me uvx excel-mcp-server streamable-http --host 0.0.0.0

Clients then send Authorization: Bearer change-me. Put a TLS-terminating reverse proxy in front of it for use across networks.

Docker

docker build -t excel-mcp-server .
docker run -p 8017:8017 -v "$PWD/workbooks:/data" -e EXCEL_MCP_AUTH_TOKEN=change-me excel-mcp-server

Configuration

Tools

Every parameter is documented in TOOLS.md. Parameters mean the same in every tool:

Tools that change a workbook return what they changed (sheet, range, name) so that the next call can refer to it. Charts and images are selected by name, as listed by describe_sheet.

Writing macros (opt-in)

With --allow-vba-write (or EXCEL_MCP_ALLOW_VBA_WRITE=1) the server can set the code of standard, class, workbook and sheet modules in .xlsm and .xltm files, delete standard and class modules, and create new .xlsm/.xltm workbooks. The server only stores the code; it never runs it, and Excel asks before enabling macros. Digitally signed VBA projects are refused, since any change would invalidate the signature.

Warning: macro code runs with your user's rights once you enable macros in Excel. A model that reads untrusted content could be tricked into writing harmful code. Enable this option only for trusted workflows, keep --allow-dir narrow, and read the code before you enable macros. The tools are never offered in --read-only mode.

Security

• Formulas are parsed before they are written. Functions that reach the network or other programs (WEBSERVICE, IMAGE, RTD, CALL, Google Sheets IMPORTXML and others), Excel 4.0 macro functions (FILES, GET.WORKBOOK, RUN and others), DDE links and references to other workbooks are rejected. HYPERLINK is accepted with a fixed http(s)://, mailto: or #Sheet!A1 link only.
• Paths are resolved, including symlinks, before they are checked against the allowed folders. Network (UNC) and Windows device paths are always rejected.
• A single call processes at most 100,000 cells, and large reads are returned in pages.
• Cell contents are data from files. The server tells the model not to follow instructions found in them, but review what an assistant does with workbooks from untrusted sources.

Please report vulnerabilities privately; see SECURITY.md.

Limitations

• Formulas are stored in the file, and Excel calculates them when it opens it. So that read_range is useful before that, values mode calculates formulas that have no saved result with a built-in calculator (about 260 functions: math, statistics, financial and bond, dates, text, lookup, logical, LET, sorting and filtering). Results Excel saved are always preferred. A formula the calculator cannot reproduce exactly as Excel does (an unsupported function, a circular reference, or an Excel quirk it does not replicate) is returned as null and listed in uncalculated with the reason; it is never guessed. Ranges in a formula are reduced to the formula's own row or column where Excel's ordinary (not array-entered) formulas do the same, and volatile functions such as RAND are not calculated. The calculator is checked against more than 2,500 formulas recorded from real Excel (tests/fixtures/formula_golden.json).
• Functions Excel added after 2007 (IFS, XLOOKUP, STDEV.S, SORT, ...) are written with the _xlfn. prefix Excel expects, wherever formulas are stored (cells, copied and sorted cells, conditional formats, data validation, defined names).
• Legacy .xls and .csv files are not supported.
• PivotTables are created from a snapshot and can use text, number and date columns of up to 100,000 cells; Excel refreshes them from the live source data. They support number formats, "show values as" (percent of total, row, column or parent, difference from, running total, rank), sorting by label or value, date and number grouping, calculated fields, compact, outline and tabular layouts, subtotals on or off, filters with chosen items and several value fields as columns or rows. The figures written into the cells are the ones Excel shows after a refresh, checked against about 200 PivotTables recorded from real Excel (tests/fixtures/pivot_golden.json). The exceptions: items that tie when sorted by value may swap places on refresh, and values_in: "rows" cannot be combined with rank figures or, with subtotals, other figures along a field, because Excel mixes the value fields up there.
• add_slicer adds slicers (Insert > Slicer) for tables and PivotTables, and timelines for date fields of PivotTables: field, caption, position and size, columns, style, sort, selected items (or a period) and "hide items with no data". Selecting items filters as clicking does: table rows are filtered and hidden; PivotTable items are hidden and the figures recalculated from the source, which Excel confirms on refresh (about 200 PivotTables are checked against Excel, and the slicer variants against Excel's own results). One slicer can filter several PivotTables that share a cache, such as those of copied sheets. Limits: a PivotTable made or refreshed by Excel keeps its figures in the cells (the hidden items and a refresh-on-open mark are stored, so Excel recalculates when it opens the file); fields grouped in a PivotTable take no slicer.
• Inserting or deleting rows and columns, and renaming a sheet, update references like Excel. Hyperlink targets and 3D references (Sheet1:Sheet3!A1) are left alone (Excel does the same). An edit that cuts through an array formula, a PivotTable, a table header or two tables at once is refused. Inserted cells take the formatting, row height and column width of the line above or to the left (nothing at the first row or column), and calculated table columns are filled into rows inserted in a table.
• Editing a workbook keeps what the tools cannot change: sparklines, extended conditional formats and validation, slicers and timelines, newer charts (waterfall, histogram, treemap and others), threaded comments, shapes, form controls, linked data types and custom XML stay as Excel saved them and move with inserted or deleted rows and columns and renamed sheets. copy_sheet copies sparklines, slicers and timelines (as Excel does), the Excel 2010 half of conditional formats (data bars, icon sets) and the Excel 2016 charts made by create_chart, but not the others. Deleting a sheet removes slicers that only it used; slicers that would be left without their PivotTable block the deletion, and deleting a table, or the column a table slicer filters, removes the slicer. Digital signatures are removed, as Excel does when a signed file changes.
• Formulas that return several values (FILTER, SORT, UNIQUE, SEQUENCE, A2:A9*2) are stored as dynamic array formulas, as Excel stores them, and spill into the cells next to them. A cell in the way blocks the spill (Excel shows #SPILL!), and write_range reports it. Where the calculator cannot tell how large a result is, only the formula's cell is stored and Excel fills in the rest when it opens the file.

Upgrading from 1.x

Version 2.0 makes tool and parameter names consistent across tools, which breaks 1.x clients and saved prompts. The changelog has a table that maps every 1.x name to its 2.0 replacement: Upgrading from 1.x. Coming from 0.x? See the 1.0.0 notes first.

Contributing

Contributions are welcome. See CONTRIBUTING.md.

License

MIT. See LICENSE.