LogiSheets

From sheets to systems. LogiSheets is a web-based spreadsheet built on a Rust engine compiled to WebAssembly — it reads, manipulates, and writes real .xlsx files, and runs the same engine in the browser and on Node. But it's more than a grid: with structured data (Blocks) that carry schema, types, and validation, and a plugin system (Crafts) that turns workbooks into real applications, a LogiSheets spreadsheet stops being a static document and becomes a building block of an actual system.

▶ See it in action — Factory Simulator live demo

An interactive simulation game built entirely on LogiSheets — Blocks, live formulas, and clickable cell interactions in the browser. The best one-minute tour of what the engine can do.

📖 Documentation: docs.logisheets.com

Why LogiSheets

• One engine, everywhere. The core spreadsheet engine is written in Rust and compiled to WASM. The exact same logic powers the browser app and a headless Node runtime — no reimplementation, no drift.
• Real Excel files. Read and write .xlsx with formulas, styles, and structure preserved.
• Structured data (Blocks). A Block keeps a region of cells together as a coherent, schema-aware table — cells are addressed by stable IDs, so inserts and deletes never break references. Fields carry types, validation rules, uniqueness, and required constraints.
• Built to extend. A rich API surface plus a plugin system (Crafts) let you add features without forking the core. The logic layer is engine-neutral and reusable from any host.
• AI-native. logician is an agent toolkit that operates workbooks through structured tools; it powers Watson, the in-app AI assistant, and runs equally well on Node.
• Fast & correct. Dependency-tracked recalculation and persistent (immutable) data structures give efficient undo/redo without cloning the whole workbook.

Crafts — the plugin system

Crafts are self-contained mini-apps that extend LogiSheets through the same public API the core uses. They're written in plain JavaScript/TypeScript, so the entire rich frontend ecosystem — UI libraries, charts, editors, AI SDKs — can be brought right into the spreadsheet. Shipped examples live under crafts/:

• factory-simulator — interactive simulation game (zh / en) showcasing Blocks, formulas, and craft interactions. ▶ Try it live
• Watson — the in-app AI assistant (built on logician)
• what-if-calculator — scenario analysis over workbook values
• markdown-table-extractor — turn Markdown tables into Blocks

Documentation

Guides, API reference, and tutorials live at docs.logisheets.com (source in docs/).

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Architecture

LogiSheets is layered so that logic lives in exactly one place and every host reuses it:

flowchart TD
    engine["crates/ — Rust engine<br/>formula eval · deps · undo/redo · .xlsx I/O"]
    web["logisheets-web<br/><i>(--target web)</i>"]
    node["logisheets (node)<br/><i>(--target nodejs)</i>"]
    core["logisheets-core<br/>all extension logic · UI-free"]
    app["Browser App<br/>core + rendering"]
    runtime["logisheets-runtime<br/>headless Node engine"]
    logician["logician<br/>AI toolkit"]
    crafts["Crafts<br/>plugins"]

    engine -->|wasm-pack| web
    engine -->|wasm-pack| node
    web --> core
    node --> core
    core --> app
    core --> runtime
    core --> logician
    core --> crafts

    subgraph wrappers ["thin WASM wrappers"]
        web
        node
    end

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The WASM wrappers expose the engine over a simple RPC surface and carry no extension logic. logisheets-core holds the portable logic and depends on the engine only for types — the concrete Client is injected by each host, so the same code runs in the browser and on Node. Rendering stays in the browser layer.

Packages

Package	Path	Description
logisheets-rs	crates/api	Rust API for the spreadsheet engine
logisheets-web	packages/web	Browser WASM SDK (/pure subpath for WASM-free use)
logisheets (node)	packages/node	Node.js WASM bindings
logisheets-core	packages/core	Engine-neutral extension logic, shared by every host
logisheets-runtime	packages/runtime	Headless spreadsheet runtime for Node
logisheets-engine	packages/engine	Canvas-based spreadsheet UI component — watermarked, contact us for removal
logisheets-formula-editor	packages/formula-editor	CodeMirror 6 formula editor
logician	packages/logician	AI agent toolkit for operating workbooks (browser + Node)

Contributing

Issues and pull requests are welcome.

License

MIT — see LICENSE.