# Show HN: SheetMog – OSS Excel alternative and headless SDK

> Source: <https://github.com/fundamental-research-labs/mog>
> Published: 2026-06-04 21:20:21+00:00

Mog is a spreadsheet engine, app runtime, and SDK stack for building workbook-aware agents, automations, and embedded spreadsheet experiences.

Try it live at [mog.shortcut.ai](https://mog.shortcut.ai/).

| I want to... | Start here | Useful command |
|---|---|---|
| Build Mog from source |
|

`pnpm typecheck`

[Use Mog as a library](#use-mog-as-a-library)`pnpm add @mog-sdk/node`

[Develop Mog](#develop-mog)`pnpm check:publish-readiness:fast`

Use `@mog-sdk/node`

for headless workbook automation in Node.js and agent
workflows.

```
pnpm add @mog-sdk/node
js
import { createWorkbook } from '@mog-sdk/node';

const wb = await createWorkbook();
const ws = wb.activeSheet;

await ws.setCell('A1', 42);
await ws.setCell('A2', '=A1*2');

console.log(await ws.getCell('A2'));
await wb.dispose();
```

Use `@mog-sdk/embed`

for browser, React, and Web Component embeds. See:

This is a large monorepo. Start with the package or surface you are changing, then run the smallest relevant verification gate.

Use `dev-v0.7.2`

as the exclusive development branch for this repo unless a
task explicitly names another branch. Do not base new local work on `dev`

.

```
pnpm install --frozen-lockfile
pnpm typecheck
pnpm test
cargo check -p compute-core --lib --locked
cargo test -p compute-core --locked
```

Common package checks:

```
pnpm --filter @mog-sdk/node test
pnpm --filter @mog-sdk/embed test
pnpm --filter @mog-sdk/sheet-view test
pnpm check:publish-readiness:fast
pnpm check:external-fixtures
```

CI and non-eval publish readiness gates are documented in
[CI Gates](/fundamental-research-labs/mog/blob/main/docs/development/ci-gates.md).

If you are a coding agent, read [AGENTS.md](/fundamental-research-labs/mog/blob/main/AGENTS.md) before editing code.

| Area | Paths |
|---|---|
| Spreadsheet app | `runtime/spreadsheet-app` , `apps/spreadsheet` , `shell` |
| Node SDK | `runtime/sdk` |
| Embeds | `runtime/embed` , `views/sheet-view` |
| Rust compute engine | `compute/core` |
| Public TypeScript contracts | `contracts` |
| Kernel and services | `kernel` |
| External consumer fixtures | `fixtures/external` |
| Architecture docs | `docs` |

MIT. See [LICENSE](/fundamental-research-labs/mog/blob/main/LICENSE).