# Excel MCP Server
A high-performance [Model Context Protocol](https://modelcontextprotocol.io/) (MCP) server that gives AI assistants full control over Excel spreadsheets. Built in Rust with [zavora-xlsx](https://github.com/zavora-ai/zavora-xlsx) for native xlsx read/write and [rmcp](https://github.com/modelcontextprotocol/rust-sdk) for the MCP protocol layer.
**74 tools** covering the complete Excel feature set — cell I/O, formatting, 14 chart types, pivot tables with calculated fields, slicers, timelines, form controls, conditional formatting, data validation, images, shapes, threaded comments, formula recalculation, encrypted save/open, and more.
## Install
```bash
cargo install excel-mcp-server
```
This compiles and installs the binary to `~/.cargo/bin/excel-mcp-server`.
> Requires [Rust](https://rustup.rs/) 1.85+. If you don't have Rust: `curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh`
## Client Configuration
### Claude Desktop
Add to `claude_desktop_config.json`:
```json
{
"mcpServers": {
"excel": {
"command": "excel-mcp-server"
}
}
}
```
### Kiro
Add to `.kiro/settings/mcp.json`:
```json
{
"mcpServers": {
"excel": {
"command": "excel-mcp-server",
"autoApprove": []
}
}
}
```
### Cursor
Add to `.cursor/mcp.json`:
```json
{
"mcpServers": {
"excel": {
"command": "excel-mcp-server"
}
}
}
```
### HTTP Mode
For web-based MCP clients:
```bash
excel-mcp-server http
```
Starts a streamable HTTP server on `127.0.0.1:8080`. Point your client at `http://localhost:8080/mcp`.
```bash
BIND_ADDRESS=0.0.0.0:3000 excel-mcp-server http
```
## Features
- **Create, open, edit, and save** xlsx files through natural language
- **Read and analyze** spreadsheets with pagination, search, and CSV export
- **Full formatting** — bold, italic, colors, borders, number formats, alignment, merge
- **14 chart types** — bar, column, line, pie, scatter, area, doughnut, waterfall, funnel, treemap, sunburst, histogram, box & whisker, map
- **Chart enhancements** — data tables, 3D views, error bars, axis formatting/bounds/log scale, drop lines, high-low lines, gradients, bubble sizes, alt text, preset styles
- **Pivot tables** — calculated fields, date/range grouping, subtotals, grand totals, value formats, row stripes, layout options
- **Slicers and timelines** — interactive pivot table filters
- **Form controls** — buttons, checkboxes, dropdowns, spinners
- **Conditional formatting** — cell value rules, 2/3-color scales, data bars, icon sets
- **Data validation** — dropdowns, number/date ranges, text length, custom formulas
- **Tables, sparklines, images, shapes** — full Excel feature coverage
- **Threaded comments** — modern conversation-style comments with replies and timestamps
- **Formula recalculation** — 58-function engine with dependency graph, evaluated before every save
- **Multiple save formats** — xlsx, template (.xltx), encrypted (password-protected), parallel compression
- **Open encrypted** — password-protected workbook support
- **Named ranges** — full CRUD with workbook and sheet-level scoping
- **Sheet metadata** — read used range, hyperlinks, merged ranges, embedded charts
- **Custom XML parts** — add and read custom XML by namespace
- **Custom document properties** — text, number, integer, boolean, datetime
- **Two transports** — stdio for CLI clients, streamable HTTP for web clients
- **In-memory workbook store** — 10-workbook capacity with 30-minute TTL eviction
## Tools Reference (74 tools)
### Workbook Lifecycle (4)
| `create_workbook` | Create a new empty workbook in memory |
| `open_workbook` | Open an existing xlsx file (edit or read-only mode) |
| `save_workbook` | Save to disk as xlsx (formulas recalculated automatically) |
| `close_workbook` | Close and free memory |
### Workbook Configuration (1)
| `configure_workbook` | Set calc mode (auto/manual), active sheet, document properties |
### Sheet Management (7)
| `list_sheets` | List all sheet names |
| `get_sheet_dimensions` | Get used range, row count, column count |
| `describe_workbook` | Sheet names, dimensions, and sample data |
| `add_sheet` | Add a new worksheet |
| `rename_sheet` | Rename a worksheet |
| `delete_sheet` | Delete a worksheet |
| `move_worksheet` | Reorder a worksheet |
### Reading (4)
| `read_sheet` | Read data with optional range and pagination |
| `read_cell` | Read a cell's value, type, and formula |
| `search_cells` | Search by value or pattern across sheets |
| `sheet_to_csv` | Export as CSV string |
### Writing (5)
| `write_cells` | Batch write to multiple cells (auto-detects types) |
| `write_row` | Write values rightward from a cell |
| `write_column` | Write values downward from a cell |
| `write_rich_text` | Write mixed bold/italic/color text runs |
| `write_json_rows` | Write JSON objects as rows with auto headers and type detection |
### Formulas (1)
| `write_formula` | Regular, array (CSE), or dynamic (Excel 365 spill) formulas |
### Cell Operations (1)
| `manage_cell` | Write formatted blank or clear content/formatting |
### Formatting (4)
| `set_cell_format` | Bold, italic, colors, borders, number format, alignment on a range |
| `merge_cells` | Merge a range into one cell |
| `set_row_column_format` | Format an entire row or column |
| `set_dimensions` | Column width, row height, column range width, default row height |
### Layout (5)
| `freeze_panes` | Freeze rows/columns for scrolling |
| `autofit_columns` | Auto-fit widths based on content |
| `set_selection` | Set the active cell |
| `set_visibility` | Hide/unhide rows or columns |
| `set_sheet_settings` | Hidden, zoom, gridlines, tab color, right-to-left |
### Charts (8)
| `add_chart` | Bar/column/line/pie/scatter/area/doughnut with series, trendlines, markers, error bars, gradients, axis formatting, data tables, 3D views, alt text, preset styles |
| `add_waterfall_chart` | Waterfall (ChartEx) with increase/decrease/total points |
| `add_funnel_chart` | Funnel (ChartEx) |
| `add_treemap_chart` | Treemap (ChartEx) with per-point colors |
| `add_sunburst_chart` | Sunburst (ChartEx) for hierarchical data |
| `add_histogram_chart` | Histogram with bin control and Pareto overlay |
| `add_box_whisker_chart` | Box & whisker with outliers, mean markers, inner points |
| `add_map_chart` | Geographic map with country/region levels |
### Interactive Controls (3)
| `add_slicer` | Interactive pivot table filter |
| `add_timeline` | Date-based pivot table filter |
| `add_form_control` | Button, checkbox, dropdown, or spinner |
### Tables & Data Features (4)
| `add_table` | Excel Table with headers, autofilter, style |
| `add_conditional_format` | Cell value, color scales, data bars, icon sets |
| `add_data_validation` | Dropdowns, number/date ranges, custom formulas |
| `add_sparkline` | Line, column, or win/loss sparkline |
### Images & Shapes (2)
| `add_image` | Embed PNG or JPEG |
| `add_shape` | Rectangle, ellipse, arrow, callout, text box with fill and outline |
### Pivot Tables (1)
| `add_pivot_table` | Row/column/value/filter fields, aggregation, calculated fields, date/range grouping, subtotals, grand totals, value formats, layout |
### Page Setup (1)
| `set_page_setup` | Landscape, paper size, margins, fit-to-page, print area, headers/footers, gridlines |
### Comments & Links (3)
| `manage_comments` | Add or read legacy comments/notes |
| `add_threaded_comment` | Modern threaded comments with replies and timestamps |
| `add_link` | External URLs or internal sheet references |
### Named Ranges (2)
| `manage_defined_names` | Add or list defined names |
| `manage_named_ranges` | Full CRUD: add, add_scoped, update, remove, list with scope |
### Row/Column Manipulation (2)
| `modify_rows` | Insert or delete rows |
| `modify_columns` | Insert or delete columns |
### Protection (3)
| `group` | Group rows/columns into outlines |
| `protect` | Protect sheet/workbook or unprotect ranges |
| `protect_sheet_advanced` | Granular protection (allow/deny insert, delete, format, sort per feature) |
### Autofilter & Errors (2)
| `manage_autofilter` | Set autofilter with optional column filtering |
| `ignore_error` | Suppress green triangle error indicators |
### Document Properties (2)
| `set_doc_properties` | Title, author, subject, description, keywords, category, company |
| `set_custom_property` | Custom properties (text, number, integer, bool, datetime) |
### Advanced Save/Open (2)
| `save_workbook_advanced` | Save as template, encrypted, or parallel. Formulas recalculated. |
| `open_workbook_encrypted` | Open password-protected workbooks |
### Read Enhancements (3)
| `read_cell_comment` | Read a single cell's comment |
| `read_cell_format` | Read a cell's formatting |
| `read_sheet_metadata` | Used range, hyperlinks, merged ranges, charts — individually or all |
### Workbook Features (4)
| `add_chart_sheet` | Dedicated chart-only sheet |
| `manage_custom_xml` | Add or read custom XML parts by namespace |
| `add_connection` | Add external data connection |
| `set_sst_threshold` | Shared string table optimization threshold |
## Example Workflow
```
1. create_workbook {}
→ { workbook_id: "abc-123", sheets: ["Sheet1"] }
2. write_row { workbook_id: "abc-123", sheet_name: "Sheet1",
start_cell: "A1", values: ["Product", "Q1", "Q2", "Q3", "Q4"] }
3. write_row { ..., start_cell: "A2", values: ["Widget", 150, 200, 180, 220] }
4. set_cell_format { ..., range: "A1:E1", bold: true,
background_color: "#4472C4", font_color: "#FFFFFF" }
5. add_chart { ..., chart_type: "column",
series: [{ values: "Sheet1!$B$2:$E$2",
categories: "Sheet1!$B$1:$E$1", name: "Widget" }],
title: "Quarterly Sales", cell: "A5",
style: 26, show_data_table: true }
6. save_workbook { ..., file_path: "./quarterly_report.xlsx" }
```
## Architecture
```
src/
├── main.rs Entry point — stdio or HTTP transport
├── server.rs MCP tool router — 74 tools registered
├── store.rs In-memory workbook store with TTL eviction
├── lib.rs Crate root
├── error.rs Error types
├── cell_ref.rs A1 notation parsing
├── engines/
│ └── zavora.rs zavora-xlsx engine adapter + recalculate
├── tools/
│ ├── workbook.rs create, open, save, close
│ ├── read.rs read_sheet, read_cell, search, CSV
│ ├── write.rs write_cells, write_row, write_column
│ ├── format.rs set_cell_format, merge_cells
│ ├── charts.rs Basic chart support
│ ├── tables.rs Excel Tables
│ ├── conditional.rs Conditional formatting
│ ├── validation.rs Data validation
│ ├── sparklines.rs Sparklines
│ ├── images.rs Image embedding
│ ├── layout.rs Freeze panes
│ ├── sheets.rs Sheet management
│ └── expanded.rs All advanced tools (charts, pivots, controls, etc.)
└── types/
├── inputs.rs Input structs for all 74 tools
├── enums.rs Chart types, formats, validation rules
└── responses.rs JSON response builders
```
### Workbook Store
- **Capacity**: 10 concurrent workbooks
- **TTL**: 30-minute inactivity timeout with automatic eviction
- **Thread-safe**: `Arc<RwLock<WorkbookStore>>`
- Every `create_workbook` or `open_workbook` returns a `workbook_id` handle
- All operations reference this handle
- `save_workbook` recalculates all formulas before writing
### Response Format
Success:
```json
{ "status": "success", "message": "...", "data": { ... } }
```
Error:
```json
{ "status": "error", "category": "not_found", "message": "...", "suggestion": "..." }
```
Error categories: `not_found`, `io_error`, `engine_unsupported`, `capacity_exceeded`
## Development
```bash
git clone https://github.com/zavora-ai/excel-mcp-server.git
cd excel-mcp-server
cargo build --release # Binary at target/release/excel-mcp-server
cargo test # Run all tests
cargo clippy # Lint
cargo fmt # Format
```
## License
Apache 2.0 — see [LICENSE](LICENSE).
Copyright 2025 Zavora Technologies Ltd.