Lattice

The AI-native spreadsheet for macOS. Built in Rust, powered by MCP.

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Why Lattice

• AI-native from day one. A built-in MCP server with 65+ tools lets Claude Desktop and Claude Code read, write, sort, chart, and analyze your spreadsheets directly. No plugins, no export/import loops.
• Pure Rust, native speed. 150+ formula functions, dependency-graph recalculation, and a Canvas-rendered grid -- all compiled to a single native binary. No Electron, no GC pauses.
• 18 MB macOS app. A lightweight .dmg that launches instantly and works offline. Single-file .xlsx format syncs cleanly with Google Drive, Dropbox, and iCloud.

Quick Demo

Connect Lattice to Claude Desktop, then ask:

"Create a new sheet called Q1 Revenue. Add columns for Month, Product, Units, Price, and Revenue. Fill in sample data for Jan--Mar with 3 products. Add a SUM row at the bottom and create a bar chart of revenue by product."

Claude calls Lattice MCP tools (write_cell, create_chart, sort_range, ...) and builds the spreadsheet live -- no copy-pasting, no manual formatting.

Features

Category	Highlights
Core	Cell editing, undo/redo, clipboard, merge cells, freeze panes, auto-fill, find & replace, conditional formatting, data validation, pivot tables
Formulas	128 functions -- SUM, VLOOKUP, XLOOKUP, INDEX/MATCH, QUERY, IMPORTRANGE, XIRR, LAMBDA, LET, ARRAYFORMULA, and more
Charts	13 types -- bar, line, pie, scatter, area, combo, histogram, candlestick, treemap, waterfall, radar, bubble, gauge
AI / MCP	65+ tools, 5 resources, 5 prompts -- cell ops, sheet ops, data analysis, charting, formatting, file I/O, sorting, filtering
File I/O	Read/write: .xlsx, .xls, .ods, .csv, .tsv. Export: JSON, PDF
App	macOS menu bar, auto-save, file watcher, dark mode, SF Pro typography

Install

Homebrew

brew tap puneet2019/lattice
brew install --cask lattice

Download DMG

Grab the latest .dmg from Releases.

Build from Source

Requires macOS 13+, Rust stable (rustup), and Node.js 20+.

git clone https://github.com/puneet2019/lattice.git
cd lattice
make dev        # Start dev server with hot reload
make test       # Run all 1,323 tests
make bundle     # Build release .dmg

MCP Setup

Claude Desktop

Add to ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "lattice": {
      "command": "/Applications/Lattice.app/Contents/MacOS/lattice",
      "args": ["--mcp-stdio"]
    }
  }
}

Claude Code

claude mcp add lattice /Applications/Lattice.app/Contents/MacOS/lattice --args --mcp-stdio

Once connected, Claude can call tools like read_range, write_cell, describe_data, sort_range, create_chart, and import_range directly against your open spreadsheet.

Architecture

macOS App (.dmg, ~18 MB)
  Tauri v2 (WKWebView + Rust backend)
    Frontend -- SolidJS + Canvas grid
    Rust backend
      lattice-core       Spreadsheet engine (128 formulas, dependency graph, cell storage)
      lattice-io         File I/O (xlsx, xls, ods, csv, tsv, json, pdf)
      lattice-mcp        MCP server (65+ tools, 5 resources, 5 prompts)
      lattice-charts     SVG chart generation (13 chart types)
      lattice-analysis   Statistical and financial analysis

The Rust backend is the single source of truth. The frontend communicates via Tauri invoke(). MCP and GUI share state through Arc<RwLock<Workbook>> with a tokio broadcast channel for live sync.

Contributing

See CONTRIBUTING.md for setup instructions, code style, and PR process.

Looking for a place to start? Check out good first issues.

License

MIT -- Copyright 2026 Puneet Mahajan