GridCraft MCP: a spreadsheet your agent can drive

Get the CLI

The 0.5.0 release ships gridcraft-cli for macOS (gridcraft-cli-0.5.0-macos-universal.zip, signed and notarized). On other systems, build it from the source code with Rust: cargo install --path apps/gridcraft-cli in a clone of the repository.

Set up with Claude Code

For a headless workbook session (no window):

claude mcp add gridcraft -- gridcraft-cli mcp

Or add it to your agent’s MCP configuration (.mcp.json in a project for Claude Code):

{
  "mcpServers": {
    "gridcraft": {
      "command": "gridcraft-cli",
      "args": ["mcp"]
    }
  }
}

Use ["mcp", "--in", "/path/book.xlsx"] to start with a file open, or ["mcp", "--sample", "budget"] for one of the samples.

Drive the desktop app you are looking at

Start the desktop app with its control channel, then point the MCP server at it:

gridcraft --control 7979
claude mcp add gridcraft-app -- gridcraft-cli mcp --connect 7979

In this mode the agent works in the open window, and it can also take screenshots of it.

What the agent gets

• Read and write: inspect_workbook, read_range (values, formulas or displayed text), write_range (strings that start with = are formulas), set_cell, get_cell.
• Formulas: evaluate_formula works out a formula without changing the sheet; list_functions lists the worksheet functions with their signatures.
• Shape the data: format_range, create_table, insert_chart, sort_range, filter, select.
• Files and history: open_workbook, save_workbook, new_workbook (.xlsx, .csv, .tsv, .json, .html), undo, redo.
• Everything else: execute_command runs any of GridCraft’s commands, and list_commands finds them with their parameters.

The server also offers the open workbook, the command list and the function list as read-only resources. Results are JSON text, and a failed call says why in plain words.

Prompts to try

• “Open sales.xlsx, add a Total column that sums Q1 to Q4 for each region, make the header bold and save it.”
• “Read the Budget sheet, find categories where Actual is over Budget, and fill those rows light red.”
• “Create a table from A1:F40, sort it by Revenue descending and insert a clustered column chart of the top 10.”

Without MCP: the CLI on its own

gridcraft-cli info book.xlsx                         # sheets, used ranges, tables, charts, names
gridcraft-cli cat book.xlsx --range A1:F20             # aligned table of displayed values
gridcraft-cli eval '=PMT(5%/12,360,-300000)'           # evaluate a formula
gridcraft-cli convert book.xlsx data.csv --sheet Sales # .xlsx, .csv, .tsv, .json or .html by extension
gridcraft-cli run --in book.xlsx --cmd 'home.bold={"range":"A1:C1"}' --out book.xlsx
gridcraft-cli commands --search chart                  # every command and its parameters

FAQ

Source: the GridCraft MCP guide, CLI reference and control protocol. Flags and tools can change between releases; check gridcraft-cli commands and the docs for your version.