chore(release): 7.11.0 [skip ci]

# [7.11.0](https://git.datacontroller.io/dc/dc/compare/v7.10.1...v7.11.0) (2026-07-20)

### Bug Fixes

* audit-skipping syntax correction ([ad7efc9](ad7efc90bc))
* **editor:** ignore cell validation on rows marked for delete ([70c5805](70c5805743))
* explicit use of .sashdat in dc_casload ([6a95067](6a95067618))
* refactor mf_wordsinstr1butnotstr2 and added a wide table to test suite ([be94c68](be94c68f35))
* retry the startup service request once before failing ([5391df8](5391df8f04))
* run dc_casload for dq tables in getdata.  Closes [#264](#264). ([6b16f9b](6b16f9b364))
* updating tests, moving mpe_rowhash to core library ([c5f0e4f](c5f0e4f106))

### Features

* bumping core to get the mp_rowhash definition, [#269](#269) ([f73f5e4](f73f5e47ac))
* new hash algorithm - allows 1000+ cols.  Closes [#269](#269) ([08947f0](08947f0fc8))

.agent/skills/handsontable/SKILL.md

@@ -0,0 +1,606 @@
+---
+name: handsontable
+description: >
+  Use this skill whenever the user asks about Handsontable — a JavaScript data grid component with
+  spreadsheet-like UX. Triggers include: mentions of "handsontable", "HotTable", "data grid",
+  "@handsontable/react-wrapper", spreadsheet component in React/Angular/Vue, HyperFormula formulas
+  inside a grid, cell types (dropdown, checkbox, date, numeric) in a grid context, or questions
+  about Handsontable theming, plugins, hooks, configuration options, or column/row features. Also
+  trigger when the user wants to add an editable spreadsheet-like table to a web app, or asks about
+  copy/paste, sorting, filtering, frozen rows/columns, merged cells, or context menus in a grid.
+  This skill covers Handsontable used with any framework (React, Angular, Vue 3, vanilla JS) and
+  HyperFormula as the Formulas plugin engine inside Handsontable. Do NOT use this skill for
+  headless/standalone HyperFormula usage without Handsontable — that is covered by the separate
+  "hyperformula" skill.
+---
+
+# Handsontable
+
+Handsontable is a JavaScript **data grid component** (not a full spreadsheet application) that
+brings spreadsheet-like UX to web apps: cell editing, copy/paste, sorting, filtering, formulas,
+keyboard navigation, context menus, merged cells, frozen rows/columns, conditional formatting, data
+validation, pagination, and 400+ built-in formulas via HyperFormula.
+
+- **Latest version:** 17.1.0 (May 2026)
+- **Frameworks:** Vanilla JS/TS, React (`@handsontable/react-wrapper`), Angular (`@handsontable/angular-wrapper`), Vue 3 (`@handsontable/vue3`)
+- **React wrapper requires:** React 18+
+- **License:** Dual — free for non-commercial use (`licenseKey: 'non-commercial-and-evaluation'`), paid for commercial. Per-developer annual license, offline validation (no server connection). Tiers: Hobby (free, non-commercial), Trial (free 45 days), Standard (from $999/yr), Priority (from $1,299/yr), Enterprise (custom). See [Pricing](https://handsontable.com/pricing).
+
+Always check `references/docs-map.md` (in this skill folder) for the full organized link directory
+when you need to point the user to specific documentation or need to look up more info.
+
+### What this skill does NOT cover
+
+- **Standalone HyperFormula** (headless formula engine without a grid UI) — use the "hyperformula" skill instead.
+- **Other data grid libraries** (AG Grid, TanStack Table, etc.).
+- **Full spreadsheet applications** — Handsontable is a component you embed, not a standalone app like Google Sheets.
+
+---
+
+## React Quick Start (Recommended)
+
+### Install
+
+```bash
+npm install handsontable @handsontable/react-wrapper
+```
+
+### Minimal working example
+
+```jsx
+import { HotTable } from '@handsontable/react-wrapper';
+import { registerAllModules } from 'handsontable/registry';
+import 'handsontable/styles/handsontable.min.css';
+import 'handsontable/styles/ht-theme-main.min.css';
+
+registerAllModules();
+
+const MyGrid = () => (
+  <HotTable
+    themeName="ht-theme-main"
+    data={[
+      ['', 'Tesla', 'Volvo', 'Toyota', 'Ford'],
+      ['2019', 10, 11, 12, 13],
+      ['2020', 20, 11, 14, 13],
+      ['2021', 30, 15, 12, 13],
+    ]}
+    colHeaders={true}
+    rowHeaders={true}
+    height="auto"
+    autoWrapRow={true}
+    autoWrapCol={true}
+    licenseKey="non-commercial-and-evaluation"
+  />
+);
+
+export default MyGrid;
+```
+
+Key points:
+- `registerAllModules()` registers every built-in plugin. To reduce bundle size, import only what
+  you need — see [Modules guide](https://handsontable.com/docs/react-data-grid/modules/).
+- `height` is required (or the grid won't render). Use `"auto"`, a pixel number, or a CSS string.
+- All Handsontable configuration options are passed as props on `<HotTable>`.
+- Full installation guide: https://handsontable.com/docs/react-data-grid/installation/
+
+---
+
+## Vanilla JS Quick Start
+
+### Install
+
+```bash
+npm install handsontable
+```
+
+### CDN (jsDelivr)
+
+```html
+<script src="https://cdn.jsdelivr.net/npm/handsontable/dist/handsontable.full.min.js"></script>
+<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/handsontable/styles/handsontable.min.css" />
+<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/handsontable/styles/ht-theme-main.min.css" />
+```
+
+To pin a specific version, add `@17.1` after `handsontable` in the URL (e.g.,
+`handsontable@17.1/dist/handsontable.full.min.js`).
+
+### Minimal working example
+
+```js
+import Handsontable from 'handsontable';
+import 'handsontable/styles/handsontable.min.css';
+import 'handsontable/styles/ht-theme-main.min.css';
+
+const container = document.getElementById('grid');
+
+new Handsontable(container, {
+  data: [
+    ['', 'Tesla', 'Volvo', 'Toyota', 'Ford'],
+    ['2019', 10, 11, 12, 13],
+    ['2020', 20, 11, 14, 13],
+    ['2021', 30, 15, 12, 13],
+  ],
+  colHeaders: true,
+  rowHeaders: true,
+  height: 'auto',
+  themeName: 'ht-theme-main',
+  autoWrapRow: true,
+  autoWrapCol: true,
+  licenseKey: 'non-commercial-and-evaluation',
+});
+```
+
+Full JS docs: https://handsontable.com/docs/javascript-data-grid/installation/
+
+---
+
+## Other Frameworks
+
+### Angular (v17–19)
+
+```bash
+npm install handsontable @handsontable/angular-wrapper
+```
+
+The Angular wrapper was modernized in Handsontable v17.1 to align with Angular 17–19, simplifying setup and reducing dependencies. Earlier Angular versions are no longer the target — upgrade Angular first if you're below v17.
+
+Docs: https://handsontable.com/docs/angular-data-grid/installation/
+
+### Vue 3
+
+```bash
+npm install handsontable @handsontable/vue3
+```
+
+Docs: https://handsontable.com/docs/react-data-grid/vue3-installation/
+
+All framework wrappers share the same version number as the core library and expose the same
+configuration options. The React examples in this skill translate directly — just use the
+framework's component syntax. Note: Vue 2 (`@handsontable/vue`) is deprecated — use Vue 3.
+
+---
+
+## Theming: Light / Dark / Auto
+
+Handsontable v15+ includes a built-in theme system. Three themes ship out of the box: **main**
+(default, spreadsheet-like), **horizon** (clean, analytics-focused), **classic** (legacy
+replacement).
+
+### CSS file approach (simplest)
+
+Import the base stylesheet plus a theme:
+
+```js
+import 'handsontable/styles/handsontable.min.css';
+import 'handsontable/styles/ht-theme-main.min.css';
+```
+
+Then set the theme on the grid:
+
+```jsx
+<HotTable themeName="ht-theme-main" /* ... */ />
+```
+
+**Dark mode:**
+- System preference (auto): `themeName="ht-theme-main-dark-auto"`
+- Forced dark: `themeName="ht-theme-main-dark"`
+
+Replace `main` with `horizon` or `classic` for other themes.
+
+### Theme API approach (runtime switching)
+
+```js
+import { mainTheme, registerTheme } from 'handsontable/themes';
+
+const theme = registerTheme(mainTheme)
+  .setColorScheme('auto')       // 'light' | 'dark' | 'auto'
+  .setDensityType('comfortable'); // 'compact' | 'default' | 'comfortable'
+```
+
+Then pass it as a prop:
+
+```jsx
+<HotTable theme={theme} /* ... */ />
+```
+
+### CDN theme files
+
+```html
+<!-- Theme CSS (includes light and dark mode support) -->
+<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/handsontable/styles/ht-theme-main.min.css" />
+```
+
+In v17, dark mode is controlled via `themeName` or the Theme API — there are no separate `-dark` or
+`-dark-auto` CSS files. Load the base theme CSS above and set the mode at runtime.
+
+For CSS variable customization, the Theme Builder, Figma design system, and 200+ design tokens, see:
+- [Themes guide](https://handsontable.com/docs/react-data-grid/themes/)
+- [Theme customization](https://handsontable.com/docs/react-data-grid/theme-customization/)
+- [Theme Builder tool](https://handsontable.com/theme-builder)
+
+---
+
+## Common Configuration Patterns
+
+All options below are passed as props on `<HotTable>` (React) or in the config object (vanilla JS).
+For the full options reference: https://handsontable.com/docs/react-data-grid/api/options/
+
+### Data binding
+
+```jsx
+// Array of arrays
+data={[['A1', 'B1'], ['A2', 'B2']]}
+
+// Array of objects
+data={[{ id: 1, name: 'Alice' }, { id: 2, name: 'Bob' }]}
+columns={[{ data: 'id' }, { data: 'name' }]}
+```
+
+Docs: https://handsontable.com/docs/react-data-grid/binding-to-data/
+
+### Column & row headers
+
+```jsx
+colHeaders={['ID', 'Name', 'Price']}  // custom labels, or {true} for A, B, C...
+rowHeaders={true}                      // 1, 2, 3... or pass an array
+```
+
+### Column types (cell types)
+
+Set via the `columns` array or `cells` function. Built-in types:
+
+- `text` (default), `numeric`, `date`, `time`, `checkbox`, `select`, `dropdown`,
+  `autocomplete`, `password`, `handsontable` (nested grid), `multiselect` (v17+)
+
+```jsx
+columns={[
+  { data: 'name', type: 'text' },
+  { data: 'price', type: 'numeric', numericFormat: { pattern: '$0,0.00' } },
+  { data: 'active', type: 'checkbox' },
+  { data: 'category', type: 'dropdown', source: ['A', 'B', 'C'] },
+]}
+```
+
+Full cell types reference: https://handsontable.com/docs/react-data-grid/cell-type/
+
+### Sorting & filtering
+
+```jsx
+columnSorting={true}        // single-column sort
+// or
+multiColumnSorting={true}   // multi-column sort
+
+filters={true}              // enable column filters
+dropdownMenu={true}         // column header menu with filter UI
+```
+
+### Frozen rows/columns
+
+```jsx
+fixedRowsTop={1}
+fixedRowsBottom={1}
+fixedColumnsStart={2}
+```
+
+### Other common options
+
+```jsx
+readOnly={true}                 // entire grid read-only (or per-cell/column)
+contextMenu={true}              // right-click menu
+mergeCells={[{ row: 0, col: 0, rowspan: 2, colspan: 2 }]}
+manualColumnResize={true}
+manualRowResize={true}
+stretchH="all"                  // stretch columns to fill width: 'none' | 'last' | 'all'
+```
+
+### Per-column config with HotColumn (React)
+
+```jsx
+import { HotTable, HotColumn } from '@handsontable/react-wrapper';
+
+<HotTable data={data} licenseKey="non-commercial-and-evaluation">
+  <HotColumn title="Name" data="name" />
+  <HotColumn title="Active" data="active" type="checkbox" />
+</HotTable>
+```
+
+Docs: https://handsontable.com/docs/react-data-grid/hot-column/
+
+---
+
+## HyperFormula Integration (Formulas Plugin)
+
+HyperFormula powers Handsontable's Formulas plugin, providing 400+ spreadsheet functions (SUM,
+AVERAGE, IF, VLOOKUP, etc.). This section covers using HyperFormula **inside** Handsontable only.
+
+### Install
+
+```bash
+npm install hyperformula
+```
+
+> **Note:** Starting in Handsontable v18, HyperFormula will no longer be bundled. Install it
+> separately and pass it to the Formulas plugin.
+
+### CDN
+
+```html
+<script src="https://cdn.jsdelivr.net/npm/hyperformula/dist/hyperformula.full.min.js"></script>
+```
+
+### Simple setup (auto-created instance)
+
+Pass the `HyperFormula` class directly — Handsontable creates an instance automatically:
+
+```jsx
+import { HyperFormula } from 'hyperformula';
+
+<HotTable
+  data={[
+    ['10', '20', '=SUM(A1:B1)'],
+    ['30', '40', '=SUM(A2:B2)'],
+  ]}
+  formulas={{ engine: HyperFormula }}
+  colHeaders={true}
+  licenseKey="non-commercial-and-evaluation"
+/>
+```
+
+### External instance (for multi-sheet or shared engine)
+
+Create a HyperFormula instance with the `'internal-use-in-handsontable'` license key:
+
+```jsx
+import { HyperFormula } from 'hyperformula';
+
+const hfInstance = HyperFormula.buildEmpty({
+  licenseKey: 'internal-use-in-handsontable',
+});
+
+// Sheet 1
+<HotTable
+  data={data1}
+  formulas={{ engine: hfInstance, sheetName: 'Sheet1' }}
+  licenseKey="non-commercial-and-evaluation"
+/>
+
+// Sheet 2 — shares the same engine, enabling cross-sheet references
+<HotTable
+  data={data2}
+  formulas={{ engine: hfInstance, sheetName: 'Sheet2' }}
+  licenseKey="non-commercial-and-evaluation"
+/>
+```
+
+Cross-sheet formula example: `=SUM(Sheet1!A:A)`
+
+### Named expressions
+
+```jsx
+formulas={{
+  engine: HyperFormula,
+  namedExpressions: [
+    { name: 'TAX_RATE', expression: 0.21 },
+  ],
+}}
+```
+
+Use in cells: `=A1 * TAX_RATE`
+
+### Listening for formula changes
+
+```jsx
+<HotTable
+  formulas={{ engine: HyperFormula }}
+  afterFormulasValuesUpdate={(changes) => {
+    changes.forEach((c) => console.log(c.address, c.newValue));
+  }}
+/>
+```
+
+### Known limitations
+
+- Formulas don't work with nested object data.
+- Moving rows/columns with formulas requires the ManualRowMove / ManualColumnMove plugins (not IndexMapper).
+- `getSourceData()` operates on physical indexes; formulas use visual indexes.
+
+Full guide: https://handsontable.com/docs/react-data-grid/formula-calculation/
+HyperFormula functions list: https://hyperformula.handsontable.com/docs/guide/built-in-functions.html
+HyperFormula version compatibility table: https://handsontable.com/docs/react-data-grid/formula-calculation/#hyperformula-version-support
+
+---
+
+## Server-side data with DataProvider (v17.1+)
+
+The **DataProvider plugin** (new in v17.1) wires the grid up to a remote data source so rows are fetched, sorted, and mutated server-side instead of held in memory. Use it for datasets too large to load up front, or when the source of truth lives in a backend.
+
+The `dataProvider` option is an object with five required keys: a row-id resolver, a paginated `fetchRows` callback, and three mutation callbacks. For a read-only grid, stub the mutation callbacks with `async () => {}` — they must still be present.
+
+```jsx
+<HotTable
+  colHeaders={['ID', 'Name', 'Email']}
+  pagination={{ pageSize: 25 }}
+  columnSorting={true}
+  emptyDataState={true}
+  height={360}
+  licenseKey="non-commercial-and-evaluation"
+  dataProvider={{
+    // Required: how to extract a stable id from each row
+    rowId: 'id',
+
+    // Required: paginated fetch. `sort` is null when no column is sorted.
+    // Second arg carries an AbortSignal — pass it to fetch() so the plugin
+    // can cancel superseded requests when the user pages/sorts quickly.
+    async fetchRows({ page, pageSize, sort }, { signal }) {
+      const params = new URLSearchParams({ page, pageSize });
+      if (sort) {
+        // sort = { prop: string, order: 'asc' | 'desc' }
+        params.set('sortBy', sort.prop);
+        params.set('order', sort.order);
+      }
+      const res = await fetch(`/api/users?${params}`, { signal });
+      const { rows, totalRows } = await res.json();
+      return { rows, totalRows };
+    },
+
+    // Required. Stub with async () => {} if your grid is read-only.
+    // The plugin auto-refetches the current page after each callback resolves.
+    // See the plugin API ref for the exact payload shapes.
+    onRowsCreate: async () => {},
+    onRowsUpdate: async () => {},
+    onRowsRemove: async () => {},
+  }}
+/>
+```
+
+### Loading and error UI
+
+The plugin fires three hooks you can wire up as `<HotTable>` props for loading indicators and error surfaces:
+
+- `beforeDataProviderFetch(params)` — fires before each fetch. `params.skipLoading` is set when the plugin wants to suppress your loading indicator (e.g., during a quick refetch).
+- `afterDataProviderFetch(result)` — fires after a successful fetch.
+- `afterDataProviderFetchError(error)` — fires when `fetchRows` throws or returns a rejected promise.
+
+### Companion options
+
+The plugin is built to pair with `pagination` (paginates server-side), `columnSorting` (single-column server-side sort), and `emptyDataState` (loading + empty state UI). Enable all three when you use DataProvider.
+
+### Authoritative references
+
+- Guide: https://handsontable.com/docs/react-data-grid/server-side-data-fetching/
+- Recipe (REST API): https://handsontable.com/docs/react-data-grid/recipes/data-management/load-data-rest-api/
+- Plugin API: https://handsontable.com/docs/react-data-grid/api/data-provider/
+
+## Notifications (v17.1+)
+
+The **Notification plugin** (new in v17.1) shows non-blocking toast notifications anchored to the grid — useful for confirming saves, surfacing validation errors, or signaling background sync state. Enable with `notifications: true` and trigger via `hot.getPlugin('notifications').showMessage(...)`. See the plugin guide for placement, severity levels, and auto-dismiss timing: https://handsontable.com/docs/react-data-grid/notification/
+
+---
+
+## Events & Hooks
+
+Handsontable hooks are passed as props on `<HotTable>`:
+
+```jsx
+<HotTable
+  afterChange={(changes, source) => {
+    if (source !== 'loadData') {
+      console.log('Cell changed:', changes);
+    }
+  }}
+  beforeChange={(changes, source) => {
+    // Return false to cancel the edit
+  }}
+  afterSelection={(row, col, row2, col2) => {
+    console.log('Selected:', row, col, 'to', row2, col2);
+  }}
+/>
+```
+
+There are 100+ hooks available. Full reference: https://handsontable.com/docs/react-data-grid/api/hooks/
+
+Guide: https://handsontable.com/docs/react-data-grid/events-and-hooks/
+
+---
+
+## Accessing the Instance (Ref)
+
+Use a ref to call Handsontable's core methods:
+
+```jsx
+import { useRef } from 'react';
+
+const MyGrid = () => {
+  const hotRef = useRef(null);
+
+  const handleClick = () => {
+    const hot = hotRef.current?.hotInstance;
+    if (hot) {
+      console.log(hot.getData());       // get all data
+      hot.selectCell(0, 0);             // select a cell
+    }
+  };
+
+  return (
+    <>
+      <HotTable ref={hotRef} /* ...options */ />
+      <button onClick={handleClick}>Get Data</button>
+    </>
+  );
+};
+```
+
+Core API reference: https://handsontable.com/docs/react-data-grid/api/core/
+
+---
+
+## Performance & Large Datasets
+
+Handsontable virtualizes rendering automatically — only visible rows and columns are in the DOM, so
+grids with 10k–100k+ rows perform well out of the box. For bulk programmatic updates, wrap mutations
+in `batch()` to defer re-rendering until all changes are applied:
+
+```jsx
+hotRef.current.hotInstance.batch(() => {
+  // set many cells, add rows, etc.
+});
+```
+
+For further tuning (disabling auto-size, reducing plugin overhead), see:
+- [Performance guide](https://handsontable.com/docs/react-data-grid/performance/)
+- [Batch operations](https://handsontable.com/docs/react-data-grid/batch-operations/)
+- [Bundle size optimization](https://handsontable.com/docs/react-data-grid/bundle-size/)
+
+---
+
+## Recipes (v17+)
+
+Handsontable v17 introduced a Recipes section in the docs — ready-made patterns for common use cases
+(data validation workflows, dynamic column generation, etc.). Check the recipes index before building
+something from scratch: https://handsontable.com/docs/react-data-grid/recipes/
+
+---
+
+## Common Pitfalls
+
+- **Forgetting `height`**: The grid won't render without a `height` prop. Use `"auto"`, a pixel value, or a CSS string.
+- **Not filtering `loadData` in `afterChange`**: The `afterChange` hook fires on initial data load with `source === 'loadData'`. Always check the source to avoid infinite loops when syncing changes back to state.
+- **Using the old wrapper packages**: v17 removed `@handsontable/react` and `@handsontable/angular`. Use `@handsontable/react-wrapper` and `@handsontable/angular-wrapper`.
+- **Using legacy CSS imports**: `handsontable.full.min.css` was removed in v17. Use `handsontable/styles/handsontable.min.css` plus a theme file.
+- **Formulas with nested object data**: HyperFormula formulas don't work when `data` is an array of nested objects — use flat objects or arrays of arrays.
+- **ExportFile `columnHeaders` renamed**: In v17.1 the ExportFile plugin's `columnHeaders` option was renamed to `colHeaders` to match the table-level option. Update any `exportAsString` / `exportAsBlob` / `downloadFile` calls that pass `columnHeaders: ...`.
+
+---
+
+## Version Awareness
+
+Handsontable docs are versioned. The latest docs live at `/docs/react-data-grid/` (which redirects
+to the current version). To link to a specific version, use `/docs/17.0/react-data-grid/`.
+
+When helping a user, check which version they are on — breaking changes between major versions are
+common. Point them to the relevant migration guide if they're upgrading.
+
+For the full organized directory of documentation links, read `references/docs-map.md` in this
+skill's folder.
+
+### v17.1 changes (latest, May 2026)
+
+- **New plugins:** DataProvider (server-side row loading via `dataProvider` option), Notification (toast notifications).
+- **NestedHeaders rowspan:** column headers can now span multiple header rows.
+- **ExportFile:** XLSX export added; the `columnHeaders` option was renamed to `colHeaders` (see Common Pitfalls).
+- **Angular wrapper:** modernized for Angular 17–19; simpler setup, fewer deps.
+- **Touch:** long-press now opens the context menu on touch devices.
+- **TypeScript:** `dateFormat` option now accepts `Intl.DateTimeFormatOptions`.
+- No removals or deprecations in v17.1.
+
+### v17.0 Breaking Changes
+
+- Removed legacy wrapper packages (`@handsontable/react`, `@handsontable/angular`). Use
+  `@handsontable/react-wrapper` and `@handsontable/angular-wrapper`.
+- Removed legacy CSS (`handsontable.full.min.css`). Use `handsontable/styles/` imports.
+- Removed core-js from dependencies.
+- Removed the PersistentState plugin.
+- Deprecated bundled HyperFormula (will require separate install in v18).
+- Deprecated numbro.js, Pikaday, moment.js, DOMPurify — use native alternatives.
+
+Migration guide: https://handsontable.com/docs/react-data-grid/migration-from-16.2-to-17.0/

.agent/skills/handsontable/references/docs-map.md

@@ -0,0 +1,231 @@
+# Handsontable Documentation Map
+
+> Last verified: May 2026 · Aligned with Handsontable 17.1.0
+
+Organized link directory for all Handsontable and HyperFormula (in-grid) documentation. Use these
+to point users to the right page. Links default to the React docs; replace `react-data-grid` with
+`javascript-data-grid`, `angular-data-grid`, or prefix with `vue3-` for other frameworks.
+
+## Getting Started
+- Installation: https://handsontable.com/docs/react-data-grid/installation/
+- Demo: https://handsontable.com/docs/react-data-grid/demo/
+- Binding to data: https://handsontable.com/docs/react-data-grid/binding-to-data/
+- Server-side data fetching (DataProvider, v17.1+): https://handsontable.com/docs/react-data-grid/server-side-data-fetching/
+- Saving data: https://handsontable.com/docs/react-data-grid/saving-data/
+- Configuration options guide: https://handsontable.com/docs/react-data-grid/configuration-options/
+- Grid size: https://handsontable.com/docs/react-data-grid/grid-size/
+- Instance methods: https://handsontable.com/docs/react-data-grid/instance-methods/
+- Events and hooks: https://handsontable.com/docs/react-data-grid/events-and-hooks/
+- License key: https://handsontable.com/docs/react-data-grid/license-key/
+- Redux integration: https://handsontable.com/docs/react-data-grid/redux/
+
+## Styling & Themes
+- Themes guide: https://handsontable.com/docs/react-data-grid/themes/
+- Design system (Figma): https://handsontable.com/docs/react-data-grid/handsontable-design-system/
+- Theme customization (CSS vars, tokens): https://handsontable.com/docs/react-data-grid/theme-customization/
+- Legacy style (pre-v15): https://handsontable.com/docs/react-data-grid/legacy-style/
+- Theme Builder tool: https://handsontable.com/theme-builder
+- Figma Theme Generator: https://github.com/handsontable/handsontable-figma
+
+## Columns
+- HotColumn component (React): https://handsontable.com/docs/react-data-grid/hot-column/
+- Column headers: https://handsontable.com/docs/react-data-grid/column-header/
+- Column groups (nested headers): https://handsontable.com/docs/react-data-grid/column-groups/
+- Column hiding: https://handsontable.com/docs/react-data-grid/column-hiding/
+- Column moving: https://handsontable.com/docs/react-data-grid/column-moving/
+- Column freezing: https://handsontable.com/docs/react-data-grid/column-freezing/
+- Column widths: https://handsontable.com/docs/react-data-grid/column-width/
+- Column summary: https://handsontable.com/docs/react-data-grid/column-summary/
+- Column virtualization: https://handsontable.com/docs/react-data-grid/column-virtualization/
+- Column menu (dropdown): https://handsontable.com/docs/react-data-grid/column-menu/
+- Column filter: https://handsontable.com/docs/react-data-grid/column-filter/
+
+## Rows
+- Row headers: https://handsontable.com/docs/react-data-grid/row-header/
+- Row parent-child (nested rows): https://handsontable.com/docs/react-data-grid/row-parent-child/
+- Row hiding: https://handsontable.com/docs/react-data-grid/row-hiding/
+- Row moving: https://handsontable.com/docs/react-data-grid/row-moving/
+- Row freezing: https://handsontable.com/docs/react-data-grid/row-freezing/
+- Row heights: https://handsontable.com/docs/react-data-grid/row-height/
+- Row virtualization: https://handsontable.com/docs/react-data-grid/row-virtualization/
+- Rows sorting: https://handsontable.com/docs/react-data-grid/rows-sorting/
+- Rows pagination: https://handsontable.com/docs/react-data-grid/rows-pagination/
+- Row trimming: https://handsontable.com/docs/react-data-grid/row-trimming/
+- Row pre-populating: https://handsontable.com/docs/react-data-grid/row-prepopulating/
+
+## Cell Features
+- Clipboard (copy/paste): https://handsontable.com/docs/react-data-grid/basic-clipboard/
+- Selection: https://handsontable.com/docs/react-data-grid/selection/
+- Merge cells: https://handsontable.com/docs/react-data-grid/merge-cells/
+- Conditional formatting: https://handsontable.com/docs/react-data-grid/conditional-formatting/
+- Text alignment: https://handsontable.com/docs/react-data-grid/text-alignment/
+- Disabled cells: https://handsontable.com/docs/react-data-grid/disabled-cells/
+- Comments: https://handsontable.com/docs/react-data-grid/comments/
+- Autofill values: https://handsontable.com/docs/react-data-grid/autofill-values/
+- Formatting cells: https://handsontable.com/docs/react-data-grid/formatting-cells/
+
+## Cell Functions
+- Cell functions overview: https://handsontable.com/docs/react-data-grid/cell-function/
+- Cell renderer: https://handsontable.com/docs/react-data-grid/cell-renderer/
+- Cell editor: https://handsontable.com/docs/react-data-grid/cell-editor/
+- Cell validator: https://handsontable.com/docs/react-data-grid/cell-validator/
+- Custom cells (v17+): https://handsontable.com/docs/react-data-grid/custom-cells/
+
+## Cell Types
+- Cell type overview: https://handsontable.com/docs/react-data-grid/cell-type/
+- Numeric: https://handsontable.com/docs/react-data-grid/numeric-cell-type/
+- Date: https://handsontable.com/docs/react-data-grid/date-cell-type/
+- Time: https://handsontable.com/docs/react-data-grid/time-cell-type/
+- Checkbox: https://handsontable.com/docs/react-data-grid/checkbox-cell-type/
+- Select: https://handsontable.com/docs/react-data-grid/select-cell-type/
+- Dropdown: https://handsontable.com/docs/react-data-grid/dropdown-cell-type/
+- Autocomplete: https://handsontable.com/docs/react-data-grid/autocomplete-cell-type/
+- MultiSelect (v17+): https://handsontable.com/docs/react-data-grid/multiselect-cell-type/
+- Password: https://handsontable.com/docs/react-data-grid/password-cell-type/
+- Handsontable (nested grid): https://handsontable.com/docs/react-data-grid/handsontable-cell-type/
+
+## Formulas (HyperFormula in Handsontable)
+- Formula calculation guide: https://handsontable.com/docs/react-data-grid/formula-calculation/
+- Formulas plugin API: https://handsontable.com/docs/react-data-grid/api/formulas/
+- HyperFormula built-in functions list: https://hyperformula.handsontable.com/docs/guide/built-in-functions.html
+- HyperFormula configuration options: https://hyperformula.handsontable.com/docs/guide/configuration-options.html
+- HyperFormula custom functions: https://hyperformula.handsontable.com/docs/guide/custom-functions.html
+- HyperFormula named expressions: https://hyperformula.handsontable.com/docs/guide/cell-references.html#relative-references
+- HyperFormula license key: https://hyperformula.handsontable.com/docs/guide/license-key.html
+
+## Navigation
+- Keyboard shortcuts: https://handsontable.com/docs/react-data-grid/keyboard-shortcuts/
+- Custom shortcuts: https://handsontable.com/docs/react-data-grid/custom-shortcuts/
+- Focus scopes: https://handsontable.com/docs/react-data-grid/focus-scopes/
+- Searching values: https://handsontable.com/docs/react-data-grid/searching-values/
+
+## Accessibility
+- Accessibility guide: https://handsontable.com/docs/react-data-grid/accessibility/
+
+## Menus & Accessories
+- Context menu: https://handsontable.com/docs/react-data-grid/context-menu/
+- Undo and redo: https://handsontable.com/docs/react-data-grid/undo-redo/
+- Icon pack: https://handsontable.com/docs/react-data-grid/icon-pack/
+- Export to CSV: https://handsontable.com/docs/react-data-grid/export-to-csv/
+- Export to Excel/XLSX (v17.1+): https://handsontable.com/docs/react-data-grid/export-to-excel/
+- Notification (v17.1+): https://handsontable.com/docs/react-data-grid/notification/
+- Empty data state: https://handsontable.com/docs/react-data-grid/empty-data-state/
+
+## Dialog & Loading
+- Dialog: https://handsontable.com/docs/react-data-grid/dialog/
+- Loading indicator: https://handsontable.com/docs/react-data-grid/loading/
+
+## Internationalization
+- Language: https://handsontable.com/docs/react-data-grid/language/
+- Locale: https://handsontable.com/docs/react-data-grid/locale/
+- Layout direction (RTL/LTR): https://handsontable.com/docs/react-data-grid/layout-direction/
+- IME support: https://handsontable.com/docs/react-data-grid/ime-support/
+
+## Tools & Building
+- Modules (tree-shaking): https://handsontable.com/docs/react-data-grid/modules/
+- Custom plugins: https://handsontable.com/docs/react-data-grid/custom-plugins/
+- Custom builds: https://handsontable.com/docs/react-data-grid/custom-builds/
+- Testing: https://handsontable.com/docs/react-data-grid/testing/
+
+## Optimization
+- Batch operations: https://handsontable.com/docs/react-data-grid/batch-operations/
+- Performance: https://handsontable.com/docs/react-data-grid/performance/
+- Bundle size: https://handsontable.com/docs/react-data-grid/bundle-size/
+
+## Security
+- Security guide: https://handsontable.com/docs/react-data-grid/security/
+
+## API Reference
+- API overview: https://handsontable.com/docs/react-data-grid/api/
+- Core (instance methods): https://handsontable.com/docs/react-data-grid/api/core/
+- Hooks (all events): https://handsontable.com/docs/react-data-grid/api/hooks/
+- Configuration options (all props): https://handsontable.com/docs/react-data-grid/api/options/
+- Plugins index: https://handsontable.com/docs/react-data-grid/api/plugins/
+
+### Individual Plugin APIs
+- AutoColumnSize: https://handsontable.com/docs/react-data-grid/api/auto-column-size/
+- AutoRowSize: https://handsontable.com/docs/react-data-grid/api/auto-row-size/
+- Autofill: https://handsontable.com/docs/react-data-grid/api/autofill/
+- BindRowsWithHeaders: https://handsontable.com/docs/react-data-grid/api/bind-rows-with-headers/
+- CollapsibleColumns: https://handsontable.com/docs/react-data-grid/api/collapsible-columns/
+- ColumnSorting: https://handsontable.com/docs/react-data-grid/api/column-sorting/
+- ColumnSummary: https://handsontable.com/docs/react-data-grid/api/column-summary/
+- Comments: https://handsontable.com/docs/react-data-grid/api/comments/
+- ContextMenu: https://handsontable.com/docs/react-data-grid/api/context-menu/
+- CopyPaste: https://handsontable.com/docs/react-data-grid/api/copy-paste/
+- CustomBorders: https://handsontable.com/docs/react-data-grid/api/custom-borders/
+- DataProvider (v17.1+): https://handsontable.com/docs/react-data-grid/api/data-provider/
+- Dialog: https://handsontable.com/docs/react-data-grid/api/dialog/
+- DragToScroll: https://handsontable.com/docs/react-data-grid/api/drag-to-scroll/
+- DropdownMenu: https://handsontable.com/docs/react-data-grid/api/dropdown-menu/
+- EmptyDataState: https://handsontable.com/docs/react-data-grid/api/empty-data-state/
+- ExportFile: https://handsontable.com/docs/react-data-grid/api/export-file/
+- Filters: https://handsontable.com/docs/react-data-grid/api/filters/
+- Formulas: https://handsontable.com/docs/react-data-grid/api/formulas/
+- HiddenColumns: https://handsontable.com/docs/react-data-grid/api/hidden-columns/
+- HiddenRows: https://handsontable.com/docs/react-data-grid/api/hidden-rows/
+- Loading: https://handsontable.com/docs/react-data-grid/api/loading/
+- ManualColumnFreeze: https://handsontable.com/docs/react-data-grid/api/manual-column-freeze/
+- ManualColumnMove: https://handsontable.com/docs/react-data-grid/api/manual-column-move/
+- ManualColumnResize: https://handsontable.com/docs/react-data-grid/api/manual-column-resize/
+- ManualRowMove: https://handsontable.com/docs/react-data-grid/api/manual-row-move/
+- ManualRowResize: https://handsontable.com/docs/react-data-grid/api/manual-row-resize/
+- MergeCells: https://handsontable.com/docs/react-data-grid/api/merge-cells/
+- MultiColumnSorting: https://handsontable.com/docs/react-data-grid/api/multi-column-sorting/
+- NestedHeaders: https://handsontable.com/docs/react-data-grid/api/nested-headers/
+- NestedRows: https://handsontable.com/docs/react-data-grid/api/nested-rows/
+- Notification (v17.1+): https://handsontable.com/docs/react-data-grid/api/notification/
+- Pagination: https://handsontable.com/docs/react-data-grid/api/pagination/
+- Search: https://handsontable.com/docs/react-data-grid/api/search/
+- StretchColumns: https://handsontable.com/docs/react-data-grid/api/stretch-columns/
+- TrimRows: https://handsontable.com/docs/react-data-grid/api/trim-rows/
+- UndoRedo: https://handsontable.com/docs/react-data-grid/api/undo-redo/
+
+## Recipes (new in v17)
+- Recipes index: https://handsontable.com/docs/react-data-grid/recipes/
+- Load data from a REST API (DataProvider, v17.1+): https://handsontable.com/docs/react-data-grid/recipes/data-management/load-data-rest-api/
+
+## Upgrade & Migration
+- Changelog: https://handsontable.com/docs/react-data-grid/changelog/
+- Versioning policy: https://handsontable.com/docs/react-data-grid/versioning-policy/
+- Deprecation policy: https://handsontable.com/docs/react-data-grid/deprecation-policy/
+- Long Term Support (LTS): https://handsontable.com/docs/react-data-grid/long-term-support/
+- 16.2 → 17.0 migration: https://handsontable.com/docs/react-data-grid/migration-from-16.2-to-17.0/
+- 16.0 → 16.1 migration: https://handsontable.com/docs/react-data-grid/migration-from-16.0-to-16.1/
+- 15.3 → 16.0 migration: https://handsontable.com/docs/react-data-grid/migration-from-15.3-to-16.0/
+- 14.6 → 15.0 migration: https://handsontable.com/docs/react-data-grid/migration-from-14.6-to-15.0/
+
+## Other Framework Installation
+- JavaScript: https://handsontable.com/docs/javascript-data-grid/installation/
+- Angular: https://handsontable.com/docs/angular-data-grid/installation/
+- Vue 3: https://handsontable.com/docs/react-data-grid/vue3-installation/
+
+## SSR Examples (CodeSandbox)
+- Next.js: https://codesandbox.io/p/sandbox/kwnjph?file=https://handsontable.com/codesandbox-vm?example-dir=next.js&handsontable-version=17.1preview=true
+- Astro: https://codesandbox.io/p/sandbox/gnqcwn?file=https://handsontable.com/codesandbox-vm?example-dir=astro&handsontable-version=17.1preview=true
+- Remix: https://codesandbox.io/p/sandbox/njcjlq?file=https://handsontable.com/codesandbox-vm?example-dir=remix&handsontable-version=17.1preview=true
+- Nuxt: https://codesandbox.io/p/sandbox/r7qsjc?file=https://handsontable.com/codesandbox-vm?example-dir=nuxt&handsontable-version=17.1preview=true
+
+## CDN Links (jsDelivr) — latest
+- JS (full bundle): https://cdn.jsdelivr.net/npm/handsontable/dist/handsontable.full.min.js
+- Base CSS: https://cdn.jsdelivr.net/npm/handsontable/styles/handsontable.min.css
+- Theme Main: https://cdn.jsdelivr.net/npm/handsontable/styles/ht-theme-main.min.css
+- Theme Horizon: https://cdn.jsdelivr.net/npm/handsontable/styles/ht-theme-horizon.min.css
+- Theme Classic: https://cdn.jsdelivr.net/npm/handsontable/styles/ht-theme-classic.min.css
+- React wrapper: https://cdn.jsdelivr.net/npm/@handsontable/react-wrapper/dist/react-handsontable.min.js
+- HyperFormula: https://cdn.jsdelivr.net/npm/hyperformula/dist/hyperformula.full.min.js
+
+Pin versions by adding `@17.1` after the package name (e.g., `handsontable@17.1`).
+
+## Package Registries
+- npm: https://www.npmjs.com/package/handsontable
+- NuGet: https://www.nuget.org/packages/handsontable
+
+## Community & Support
+- Developer Forum: https://forum.handsontable.com/
+- GitHub Issues: https://github.com/handsontable/handsontable/issues
+- Stack Overflow: https://stackoverflow.com/tags/handsontable
+- Commercial support: support@handsontable.com
+- Contact form: https://handsontable.com/contact
+- Blog / Release Notes: https://handsontable.com/blog/categories/release-notes
+- Download page: https://handsontable.com/download

.agent/skills/hyperformula/README.md

@@ -0,0 +1,85 @@
+# @handsontable/hyperformula-skill
+
+An agent skill for [**HyperFormula**](https://hyperformula.handsontable.com) — the headless, open-source TypeScript spreadsheet calculation engine. It gives any AI coding agent deep, task-oriented knowledge of HyperFormula so the agent can help you integrate, configure, and debug the engine faster.
+
+This package is the npm distribution of the `hyperformula` skill maintained in [`handsontable/handsontable-skills`](https://github.com/handsontable/handsontable-skills). The package version tracks the HyperFormula product version the skill targets (e.g. `3.3.0` targets HyperFormula 3.3.0).
+
+## What's in the package
+
+A self-contained skill — plain markdown, no runtime dependencies:
+
+```
+SKILL.md        ← entry point: concepts, routing, and a docs map (YAML frontmatter + body)
+references/     ← task-oriented deep-dives the agent reads on demand
+```
+
+`SKILL.md` follows the [Agent Skills](https://claude.com/blog/skills) layout (a YAML frontmatter block with `name`/`description`, followed by markdown instructions). Any agent that can load a skill — or simply read a folder of markdown instructions — can use it.
+
+## Install
+
+```bash
+npm install @handsontable/hyperformula-skill
+```
+
+The installed package lives at `node_modules/@handsontable/hyperformula-skill`. Resolve that path programmatically with:
+
+```bash
+node -p "require.resolve('@handsontable/hyperformula-skill/SKILL.md')"
+```
+
+Then make the skill available to your agent using whichever of the following matches it:
+
+### Claude Code
+
+Copy the package into a skills directory. User scope (available in every project):
+
+```bash
+cp -r node_modules/@handsontable/hyperformula-skill ~/.claude/skills/hyperformula
+```
+
+Or project scope, from your project root:
+
+```bash
+cp -r node_modules/@handsontable/hyperformula-skill .claude/skills/hyperformula
+```
+
+### Claude API
+
+Upload the package contents (`SKILL.md` + `references/`) to the [Skills API](https://platform.claude.com/docs/en/agents-and-tools/agent-skills/overview).
+
+### OpenAI Codex
+
+Codex discovers [skills](https://developers.openai.com/codex/skills) as folders containing a `SKILL.md`, under `~/.agents/skills` (available in every repo) or `.agents/skills` in a repo (checked in for your team). Copy the package into one of those locations:
+
+```bash
+# User scope — available in every repo
+cp -r node_modules/@handsontable/hyperformula-skill ~/.agents/skills/hyperformula
+
+# Repo scope — from your project root
+cp -r node_modules/@handsontable/hyperformula-skill .agents/skills/hyperformula
+```
+
+Codex also follows symlinked skill folders, so you can instead link the installed package and let `npm install` keep it current:
+
+```bash
+ln -s "$PWD/node_modules/@handsontable/hyperformula-skill" ~/.agents/skills/hyperformula
+```
+
+### Any other agent
+
+Most coding agents support a skills, rules, or knowledge directory. Copy (or symlink) the package folder into it, for example:
+
+```bash
+# Replace <agent-skills-dir> with your agent's skills/knowledge directory
+cp -r node_modules/@handsontable/hyperformula-skill <agent-skills-dir>/hyperformula
+```
+
+If your agent reads a single instruction file rather than a folder, point it at `SKILL.md`; it links the files under `references/` so the agent can pull them in as needed. For RAG / vector-store setups, ingest `SKILL.md` together with every file under `references/` (the repository also publishes a pre-flattened `hyperformula-rag.md` for this case).
+
+## Other distribution formats
+
+The same skill source is also shipped as a drag-and-drop `.zip` (Cowork / Claude.ai web), a flattened `-rag.md` doc (RAG / vector stores), and a Claude Code plugin marketplace entry. See the [repository README](https://github.com/handsontable/handsontable-skills#readme) for details.
+
+## License
+
+MIT — see the [repository](https://github.com/handsontable/handsontable-skills/blob/main/LICENSE.txt). HyperFormula itself is separately licensed (GPLv3 or commercial); see the [licensing guide](https://hyperformula.handsontable.com/docs/guide/licensing.html).

.agent/skills/hyperformula/SKILL.md

@@ -0,0 +1,134 @@
+---
+name: hyperformula
+description: >
+  Use this skill when the user works with HyperFormula (HF) — a headless,
+  open-source TypeScript spreadsheet calculation engine. Use it when the user:
+  mentions HyperFormula or HF; wants to integrate Excel-like formulas into a
+  JS/TS app; evaluate formulas programmatically in a browser or Node.js;
+  simulate spreadsheet or Excel calculation behavior server-side; run
+  calculations over data parsed from XLSX files (e.g. via SheetJS) in code;
+  build a pricing engine, financial model, or what-if analysis in code; define
+  custom spreadsheet functions or named expressions outside of a UI context. Do
+  NOT use this skill for: general Excel questions unrelated to HF; general
+  Google Sheets questions; generic spreadsheet formula-syntax questions outside
+  an HF context; formulas used inside Handsontable (use the "handsontable"
+  skill instead).
+---
+
+# HyperFormula
+
+HyperFormula is a **headless, open-source TypeScript spreadsheet calculation engine** for embedding spreadsheet logic in any JavaScript/TypeScript application (browser or Node.js). ~420 built-in functions, dependency graph, undo/redo, i18n (17 languages). Dual-licensed: GPLv3 or commercial.
+
+- Docs: https://hyperformula.handsontable.com/
+- npm: https://www.npmjs.com/package/hyperformula
+- GitHub: https://github.com/handsontable/hyperformula
+
+## Where to go next
+
+Task-oriented references in `references/` (open the one that matches what the user is doing):
+
+- [`getting-started.md`](references/getting-started.md) — how to install, create an instance (`buildFromArray` / `buildFromSheets` / `buildEmpty`), and work with cell addresses. Open this for onboarding questions and first-run errors.
+- [`api-quickref.md`](references/api-quickref.md) — runnable examples for CRUD, rows/columns, sheets, exporting data, batching, named expressions, events, undo/redo, clipboard. Open this when implementing or debugging HF API calls.
+- [`custom-functions.md`](references/custom-functions.md) — extending HyperFormula via `FunctionPlugin`: minimal plugin, argument types, volatile functions, range arguments, returning arrays, error handling, aliases, localized names. Open this when adding or debugging custom spreadsheet functions.
+- [`configuration.md`](references/configuration.md) — `ConfigParams` options, Excel-compatibility preset, Google-Sheets preset, and config-related pitfalls (separator collisions, Node ICU, `precisionRounding` change in v3). Open this when tuning behavior or diagnosing locale issues.
+- [`vue3.md`](references/vue3.md) — Vue 3 integration: `markRaw` requirement, Composition API, Pinia/Vuex stores, `destroy()` on unmount. Open this when embedding HF in a Vue 3 app.
+- [`error-handling.md`](references/error-handling.md) — inspecting `CellError`, `ErrorType` enum, `getCellValueDetailedType`, common error causes (`#NAME?`, `#CYCLE!`, `#REF!`, …). Open this when a cell returns an error or you need to branch on result type.
+- [`general-pitfalls.md`](references/general-pitfalls.md) — cross-cutting gotchas: `destroy()` lifecycle, forcing literal strings, Excel-parity caveats, hard limits. Open this when results look wrong or memory grows unboundedly.
+
+Below this section is the **Documentation map** — the canonical directory of links to the official HyperFormula docs. Use it when pointing the user to authoritative material.
+
+## Documentation map
+
+All links resolve to `hyperformula.handsontable.com` unless noted.
+
+### Introduction
+- Welcome / Homepage: https://hyperformula.handsontable.com/
+- Demo: https://hyperformula.handsontable.com/docs/guide/demo.html
+
+### Overview
+- Quality (test coverage, CI): https://hyperformula.handsontable.com/docs/guide/quality.html
+- Supported browsers: https://hyperformula.handsontable.com/docs/guide/supported-browsers.html
+- Dependencies: https://hyperformula.handsontable.com/docs/guide/dependencies.html
+- Licensing (GPLv3 vs commercial): https://hyperformula.handsontable.com/docs/guide/licensing.html
+- Support: https://hyperformula.handsontable.com/docs/guide/support.html
+
+### Getting Started
+- Client-side installation: https://hyperformula.handsontable.com/docs/guide/client-side-installation.html
+- Server-side installation (Node.js): https://hyperformula.handsontable.com/docs/guide/server-side-installation.html
+- Basic usage: https://hyperformula.handsontable.com/docs/guide/basic-usage.html
+- Advanced usage: https://hyperformula.handsontable.com/docs/guide/advanced-usage.html
+- Configuration options guide: https://hyperformula.handsontable.com/docs/guide/configuration-options.html
+- License key setup: https://hyperformula.handsontable.com/docs/guide/license-key.html
+
+### Framework Integration
+- React: https://hyperformula.handsontable.com/docs/guide/integration-with-react.html
+- Vue: https://hyperformula.handsontable.com/docs/guide/integration-with-vue.html
+- Angular: https://hyperformula.handsontable.com/docs/guide/integration-with-angular.html
+- Svelte: https://hyperformula.handsontable.com/docs/guide/integration-with-svelte.html
+
+### Data Operations
+- Basic operations (CRUD): https://hyperformula.handsontable.com/docs/guide/basic-operations.html
+- Batch operations: https://hyperformula.handsontable.com/docs/guide/batch-operations.html
+- Clipboard operations: https://hyperformula.handsontable.com/docs/guide/clipboard-operations.html
+- Undo-redo: https://hyperformula.handsontable.com/docs/guide/undo-redo.html
+- Sorting data: https://hyperformula.handsontable.com/docs/guide/sorting-data.html
+
+### Formulas
+- Specifications and limits: https://hyperformula.handsontable.com/docs/guide/specifications-and-limits.html
+- Cell references (relative, absolute, mixed, cross-sheet): https://hyperformula.handsontable.com/docs/guide/cell-references.html
+- Types of values: https://hyperformula.handsontable.com/docs/guide/types-of-values.html
+- Types of errors: https://hyperformula.handsontable.com/docs/guide/types-of-errors.html
+- Types of operators: https://hyperformula.handsontable.com/docs/guide/types-of-operators.html
+- Order of precedence: https://hyperformula.handsontable.com/docs/guide/order-of-precendece.html
+- Built-in functions (full list, ~400): https://hyperformula.handsontable.com/docs/guide/built-in-functions.html
+- Volatile functions: https://hyperformula.handsontable.com/docs/guide/volatile-functions.html
+- Named expressions: https://hyperformula.handsontable.com/docs/guide/named-expressions.html
+- Array formulas / ARRAYFORMULA: https://hyperformula.handsontable.com/docs/guide/arrays.html
+
+### Internationalization
+- i18n features (17 languages): https://hyperformula.handsontable.com/docs/guide/i18n-features.html
+- Localizing function names: https://hyperformula.handsontable.com/docs/guide/localizing-functions.html
+- Date and time handling: https://hyperformula.handsontable.com/docs/guide/date-and-time-handling.html
+
+### Compatibility
+- Microsoft Excel compatibility: https://hyperformula.handsontable.com/docs/guide/compatibility-with-microsoft-excel.html
+- Google Sheets compatibility: https://hyperformula.handsontable.com/docs/guide/compatibility-with-google-sheets.html
+- Runtime differences (Excel & Sheets): https://hyperformula.handsontable.com/docs/guide/list-of-differences.html
+
+### Advanced Topics
+- Key concepts (AST, dependency graph, evaluation): https://hyperformula.handsontable.com/docs/guide/key-concepts.html
+- Dependency graph: https://hyperformula.handsontable.com/docs/guide/dependency-graph.html
+- Building & testing from source: https://hyperformula.handsontable.com/docs/guide/building.html
+- Custom functions (FunctionPlugin): https://hyperformula.handsontable.com/docs/guide/custom-functions.html
+- Performance: https://hyperformula.handsontable.com/docs/guide/performance.html
+- Known limitations: https://hyperformula.handsontable.com/docs/guide/known-limitations.html
+- File import: https://hyperformula.handsontable.com/docs/guide/file-import.html
+
+### Upgrade & Migration
+- Release notes / Changelog: https://hyperformula.handsontable.com/docs/guide/release-notes.html
+- 0.6 → 1.0 migration: https://hyperformula.handsontable.com/docs/guide/migration-from-0.6-to-1.0.html
+- 1.x → 2.0 migration: https://hyperformula.handsontable.com/docs/guide/migration-from-1.x-to-2.0.html
+- 2.x → 3.0 migration: https://hyperformula.handsontable.com/docs/guide/migration-from-2.x-to-3.0.html
+
+### API Reference
+- API overview: https://hyperformula.handsontable.com/docs/api/
+- HyperFormula class (all methods): https://hyperformula.handsontable.com/docs/api/classes/hyperformula.html
+- ConfigParams interface (all options): https://hyperformula.handsontable.com/docs/api/interfaces/configparams.html
+- Listeners interface (all events): https://hyperformula.handsontable.com/docs/api/interfaces/listeners.html
+
+### npm
+- npm page: https://www.npmjs.com/package/hyperformula
+
+### Community & Support
+- GitHub repo: https://github.com/handsontable/hyperformula
+- GitHub Issues: https://github.com/handsontable/hyperformula/issues
+- GitHub Discussions: https://github.com/handsontable/hyperformula/discussions
+- Developer Forum: https://forum.handsontable.com/
+- Commercial support: support@handsontable.com
+- Sales (commercial license): sales@handsontable.com
+- Contact form: https://handsontable.com/contact
+
+---
+
+> **Last updated: 2026-05-20 · Aligned with HyperFormula 3.3.0.**
+> If the user is on a newer release, confirm API shape against the latest docs (see the **Release notes** link above) before relying on this file.

.agent/skills/hyperformula/package.json

@@ -0,0 +1,34 @@
+{
+  "name": "@handsontable/hyperformula-skill",
+  "version": "3.3.0",
+  "description": "Agent skill for HyperFormula — the headless, open-source TypeScript spreadsheet calculation engine. Teaches AI coding agents how to integrate, configure, and debug HyperFormula.",
+  "license": "MIT",
+  "author": "Handsontable <hello@handsontable.com> (https://handsontable.com)",
+  "homepage": "https://github.com/handsontable/handsontable-skills#readme",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/handsontable/handsontable-skills.git",
+    "directory": "skills/hyperformula"
+  },
+  "bugs": {
+    "url": "https://github.com/handsontable/handsontable-skills/issues"
+  },
+  "keywords": [
+    "agent-skill",
+    "claude-skill",
+    "claude",
+    "anthropic",
+    "ai",
+    "hyperformula",
+    "spreadsheet",
+    "formula-engine",
+    "handsontable"
+  ],
+  "files": [
+    "SKILL.md",
+    "references/"
+  ],
+  "publishConfig": {
+    "access": "public"
+  }
+}

.agent/skills/hyperformula/references/api-quickref.md

@@ -0,0 +1,147 @@
+# API Quick Reference
+
+Runnable examples for the most-used HyperFormula APIs. Authoritative docs:
+- Basic operations: https://hyperformula.handsontable.com/docs/guide/basic-operations.html
+- Batch operations: https://hyperformula.handsontable.com/docs/guide/batch-operations.html
+- Named expressions: https://hyperformula.handsontable.com/docs/guide/named-expressions.html
+- Clipboard operations: https://hyperformula.handsontable.com/docs/guide/clipboard-operations.html
+- Undo-redo: https://hyperformula.handsontable.com/docs/guide/undo-redo.html
+- Sorting data: https://hyperformula.handsontable.com/docs/guide/sorting-data.html
+- HyperFormula class (all methods): https://hyperformula.handsontable.com/docs/api/classes/hyperformula.html
+- Listeners (all events): https://hyperformula.handsontable.com/docs/api/interfaces/listeners.html
+
+## CRUD
+
+```ts
+// Write: string, number, or formula
+hf.setCellContents({ sheet: 0, col: 0, row: 0 }, 'Hello');
+hf.setCellContents({ sheet: 0, col: 1, row: 0 }, '=A1 & " World"');
+
+// Read
+hf.getCellValue({ sheet: 0, col: 1, row: 0 });    // computed result
+hf.getCellFormula({ sheet: 0, col: 1, row: 0 });  // '=A1 & " World"'
+hf.getCellType({ sheet: 0, col: 0, row: 0 });     // CellType.FORMULA | VALUE | EMPTY
+```
+
+## Rows and columns
+
+Second arg is `[startIndex, count]`, not a list of indexes.
+
+```ts
+hf.addRows(sheetId, [rowIndex, numberOfRows]);
+hf.removeRows(sheetId, [rowIndex, numberOfRows]);
+hf.addColumns(sheetId, [colIndex, numberOfColumns]);
+hf.removeColumns(sheetId, [colIndex, numberOfColumns]);
+```
+
+## Sheets
+
+```ts
+hf.addSheet('NewSheet');
+hf.removeSheet(sheetId);
+hf.renameSheet(sheetId, 'BetterName');
+hf.countSheets();
+hf.getSheetName(sheetId);
+hf.getSheetId('SheetName');
+hf.getSheetDimensions(sheetId); // → { width, height }
+```
+
+## Export data
+
+```ts
+hf.getSheetValues(sheetId);        // computed values as 2D array
+hf.getSheetSerialized(sheetId);    // formulas/raw values as 2D array
+hf.getAllSheetsValues();            // { SheetName: values[][] }
+hf.getAllSheetsSerialized();        // { SheetName: formulas[][] }
+```
+
+## Batch operations
+
+Every `setCellContents` call triggers a full dependency-graph recalculation. Always batch when writing more than one cell.
+
+```ts
+// Preferred: batch() — returns ExportedChange[]
+const changes = hf.batch(() => {
+  hf.setCellContents({ sheet: 0, col: 0, row: 0 }, '100');
+  hf.setCellContents({ sheet: 0, col: 0, row: 1 }, '200');
+  hf.addRows(0, [2, 1]);
+});
+// `changes` contains all cells that were recalculated.
+
+// For bulk imports (value writes only):
+hf.suspendEvaluation();
+// ... hundreds of setCellContents calls ...
+hf.resumeEvaluation();  // single recalc
+
+// PITFALL: structural ops (addRows/moveRows/...) during suspendEvaluation
+// have degraded performance. Use batch() when mixing structural + value writes.
+```
+
+## Sorting
+
+`setRowOrder` takes a **permutation array**, not a comparator. Compute the new index sequence externally, then pass it in.
+
+```ts
+// Sort rows by the value in column 0
+const rowCount = hf.getSheetDimensions(0).height;
+const indexes = Array.from({ length: rowCount }, (_, i) => i);
+indexes.sort((a, b) => {
+  const va = hf.getCellValue({ sheet: 0, col: 0, row: a }) as number;
+  const vb = hf.getCellValue({ sheet: 0, col: 0, row: b }) as number;
+  return va - vb;
+});
+hf.setRowOrder(0, indexes); // e.g. [2, 0, 1, 3]
+```
+
+## Named expressions
+
+Reusable names for values or formulas. Can be global or scoped to a sheet (local shadows global).
+
+```ts
+hf.addNamedExpression('TAX_RATE', '0.21');
+hf.addNamedExpression('TOTAL_REVENUE', '=SUM(Revenue!A:A)');
+
+hf.setCellContents({ sheet: 0, col: 0, row: 0 }, '=1000 * TAX_RATE');
+
+hf.listNamedExpressions(); // all registered names
+```
+
+## Custom functions
+
+See [custom-functions.md](custom-functions.md) — `FunctionPlugin`, argument types, volatile functions, range arguments, returning arrays, error handling, aliases, localized names.
+
+## Events
+
+Subscribe via `.on()` on the instance. Full list: https://hyperformula.handsontable.com/docs/api/interfaces/listeners.html
+
+```ts
+hf.on('valuesUpdated', (changes) => {
+  changes.forEach((c) => console.log(c.address, c.newValue));
+});
+
+hf.on('sheetAdded', (addedSheetName) => { /* ... */ });
+hf.on('sheetRemoved', (removedSheetName, removedSheetData) => { /* ... */ });
+hf.on('sheetRenamed', (oldName, newName) => { /* ... */ });
+```
+
+## Undo / redo
+
+```ts
+hf.undo();
+hf.redo();
+hf.isThereSomethingToUndo();
+hf.isThereSomethingToRedo();
+hf.clearUndoStack();
+```
+
+Configure depth via `undoLimit` in `ConfigParams` (see [configuration.md](configuration.md)).
+
+## Clipboard
+
+```ts
+hf.copy({ start: { sheet: 0, col: 0, row: 0 }, end: { sheet: 0, col: 1, row: 1 } });
+hf.cut ({ start: { sheet: 0, col: 0, row: 0 }, end: { sheet: 0, col: 1, row: 1 } });
+hf.paste({ sheet: 0, col: 5, row: 5 });
+hf.isClipboardEmpty();
+hf.clearClipboard();
+```

.agent/skills/hyperformula/references/configuration.md

@@ -0,0 +1,92 @@
+# Configuration
+
+`ConfigParams` + compatibility presets + config-specific pitfalls. Authoritative docs:
+- Configuration options guide: https://hyperformula.handsontable.com/docs/guide/configuration-options.html
+- ConfigParams (all options): https://hyperformula.handsontable.com/docs/api/interfaces/configparams.html
+- Excel compatibility: https://hyperformula.handsontable.com/docs/guide/compatibility-with-microsoft-excel.html
+- Google Sheets compatibility: https://hyperformula.handsontable.com/docs/guide/compatibility-with-google-sheets.html
+
+## ConfigParams highlights
+
+Pass as the second argument to any factory method.
+
+```ts
+const hf = HyperFormula.buildEmpty({
+  licenseKey: 'gpl-v3',           // required — 'gpl-v3' for open source
+  precisionRounding: 10,          // decimal rounding precision (default 10; was 14 before v3)
+  functionArgSeparator: ',',      // separator between function arguments
+  dateFormats: ['DD/MM/YYYY', 'DD-MM-YYYY'],
+  nullDate: { year: 1900, month: 1, day: 1 },
+  leapYear1900: false,            // Excel bug compat: treat 1900 as leap year
+  maxRows: 40000,                 // max rows per sheet (default 40000)
+  maxColumns: 18278,              // max columns per sheet (default 18278 = 'ZZZ')
+  undoLimit: 20,                  // undo history depth
+  maxPendingLazyTransformations: 1000, // v3.3+ — cap accumulated lazy transformations before cleanup
+});
+```
+
+## Excel compatibility preset
+
+```ts
+const hf = HyperFormula.buildEmpty({
+  licenseKey: 'gpl-v3',
+  useArrayArithmetic: true,
+  useWildcards: true,
+  evaluateNullToZero: true,
+  leapYear1900: true,     // Excel's intentional 1900 leap-year bug
+  ignoreWhiteSpace: 'any',
+  caseSensitive: false,
+  accentSensitive: true,
+});
+```
+
+## Google Sheets compatibility preset
+
+Defaults already match Google Sheets behavior (`leapYear1900: false`, `useArrayArithmetic: false`).
+
+```ts
+const hf = HyperFormula.buildEmpty({ licenseKey: 'gpl-v3' });
+```
+
+## Config-specific pitfalls
+
+### Vue 3
+
+Vue 3 requires wrapping the instance with `markRaw` — see [vue3.md](vue3.md) for the full integration guide (React / Angular / Svelte need no special handling).
+
+### `functionArgSeparator` vs `thousandSeparator` collision
+
+These two options **cannot share a character**. European locales that use `,` as thousand separator must change the argument separator:
+
+```ts
+const hf = HyperFormula.buildEmpty({
+  licenseKey: 'gpl-v3',
+  thousandSeparator: ',',
+  decimalSeparator: '.',
+  functionArgSeparator: ';',  // must differ from thousandSeparator
+});
+```
+
+### Node.js must have full ICU
+
+String comparisons (used in `MATCH`, `VLOOKUP`, sorting) can silently produce wrong results on Node.js < 13 or builds without full ICU. Verify at startup:
+
+```ts
+// Must report 'full' (or a detailed ICU version), not 'small'.
+console.log(process.versions.icu);
+```
+
+### Tuning `maxPendingLazyTransformations` (v3.3+)
+
+HyperFormula defers some structural transformations (row/column insertions, moves) and applies them lazily. In long-lived instances with heavy mutation throughput — bulk imports, frequent undo/redo, scripted batch edits — the pending queue can grow before cleanup. v3.3 fixed the unbounded-growth leak; this option lets you cap the queue explicitly. Lower values trade memory for more frequent flush work; the default is suitable for typical UI workloads.
+
+### `precisionRounding` default changed in v3
+
+Before v3 the default was `14`. It is now `10`. Calculations relying on the old precision need an explicit override:
+
+```ts
+const hf = HyperFormula.buildEmpty({
+  licenseKey: 'gpl-v3',
+  precisionRounding: 14,  // pre-v3 behavior
+});
+```

.agent/skills/hyperformula/references/custom-functions.md

@@ -0,0 +1,174 @@
+# Custom Functions
+
+Extend HyperFormula with your own functions via `FunctionPlugin`. Authoritative doc:
+- Custom functions guide: https://hyperformula.handsontable.com/docs/guide/custom-functions.html
+
+## Minimal plugin
+
+Register **before** creating any instance — functions registered after `buildFromArray` / `buildFromSheets` / `buildEmpty` won't be available.
+
+```ts
+import { HyperFormula, FunctionPlugin, FunctionArgumentType } from 'hyperformula';
+
+class MyPlugin extends FunctionPlugin {
+  greet(ast, state) {
+    return this.runFunction(
+      ast.args,
+      state,
+      this.metadata('GREET'),
+      (name) => `Hello, ${name}!`
+    );
+  }
+}
+
+MyPlugin.implementedFunctions = {
+  GREET: {
+    method: 'greet',
+    parameters: [{ argumentType: FunctionArgumentType.STRING }],
+  },
+};
+
+const translations = { enGB: { GREET: 'GREET' }, enUS: { GREET: 'GREET' } };
+
+// PITFALL: registration MUST happen before any instance is built.
+HyperFormula.registerFunctionPlugin(MyPlugin, translations);
+
+const hf = HyperFormula.buildFromArray(
+  [['World', '=GREET(A1)']],
+  { licenseKey: 'gpl-v3' }
+);
+console.log(hf.getCellValue({ sheet: 0, col: 1, row: 0 })); // "Hello, World!"
+```
+
+## Volatile functions
+
+Mark a function as volatile so it recalculates on every change (like `RAND` or `NOW`). Volatile functions are expensive in large sheets — use sparingly.
+
+```ts
+MyPlugin.implementedFunctions = {
+  RAND_ID: {
+    method: 'randId',
+    parameters: [],
+    isVolatile: true,
+  },
+};
+```
+
+## Argument types
+
+```ts
+import { FunctionArgumentType } from 'hyperformula';
+
+// FunctionArgumentType.NUMBER
+// FunctionArgumentType.STRING
+// FunctionArgumentType.BOOLEAN
+// FunctionArgumentType.NOERROR
+// FunctionArgumentType.SCALAR
+// FunctionArgumentType.RANGE       // accepts a cell range
+// FunctionArgumentType.ANY
+```
+
+Use `optionalArg: true`, `defaultValue`, and `minValue` / `maxValue` to validate arguments declaratively:
+
+```ts
+MyPlugin.implementedFunctions = {
+  CLAMP: {
+    method: 'clamp',
+    parameters: [
+      { argumentType: FunctionArgumentType.NUMBER },
+      { argumentType: FunctionArgumentType.NUMBER, optionalArg: true, defaultValue: 0 },
+      { argumentType: FunctionArgumentType.NUMBER, optionalArg: true, defaultValue: 100 },
+    ],
+  },
+};
+```
+
+## Range arguments
+
+Use `RANGE` argument type when the function takes a cell area. The callback receives the range as a 2D array.
+
+```ts
+class SumPositivesPlugin extends FunctionPlugin {
+  sumPositives(ast, state) {
+    return this.runFunction(
+      ast.args,
+      state,
+      this.metadata('SUM_POSITIVES'),
+      (range) => {
+        let total = 0;
+        for (const row of range.data) {
+          for (const v of row) if (typeof v === 'number' && v > 0) total += v;
+        }
+        return total;
+      }
+    );
+  }
+}
+
+SumPositivesPlugin.implementedFunctions = {
+  SUM_POSITIVES: {
+    method: 'sumPositives',
+    parameters: [{ argumentType: FunctionArgumentType.RANGE }],
+  },
+};
+```
+
+## Returning arrays
+
+Custom functions can return 2D arrays. **PITFALL:** result arrays don't auto-resize when upstream dependencies change — the footprint is fixed at first evaluation.
+
+```ts
+class SplitPlugin extends FunctionPlugin {
+  splitToRow(ast, state) {
+    return this.runFunction(
+      ast.args,
+      state,
+      this.metadata('SPLIT_ROW'),
+      (text, sep) => [text.split(sep)]  // 2D array: one row, N cols
+    );
+  }
+}
+```
+
+## Error handling
+
+Return a `CellError` to signal a formula error:
+
+```ts
+import { CellError, ErrorType } from 'hyperformula';
+
+class DividePlugin extends FunctionPlugin {
+  safeDivide(ast, state) {
+    return this.runFunction(
+      ast.args,
+      state,
+      this.metadata('SAFE_DIVIDE'),
+      (a, b) => (b === 0 ? new CellError(ErrorType.DIV_BY_ZERO) : a / b)
+    );
+  }
+}
+```
+
+## Aliases and localized names
+
+Expose one method under multiple function names, or localize:
+
+```ts
+MyPlugin.aliases = {
+  HELLO: 'GREET', // calling =HELLO(x) runs the greet() method
+};
+
+const translations = {
+  enGB: { GREET: 'GREET' },
+  plPL: { GREET: 'POWITAJ' }, // =POWITAJ("Świat") in Polish
+};
+HyperFormula.registerFunctionPlugin(MyPlugin, translations);
+```
+
+## Unregister / introspect
+
+```ts
+HyperFormula.unregisterFunctionPlugin(MyPlugin);
+HyperFormula.unregisterFunction('GREET');
+HyperFormula.getRegisteredFunctionNames('enGB');
+```

.agent/skills/hyperformula/references/error-handling.md

@@ -0,0 +1,69 @@
+# Error Handling
+
+Inspect cell values that may be errors, tell error types apart, and check value shape. Authoritative docs:
+- Types of errors: https://hyperformula.handsontable.com/docs/guide/types-of-errors.html
+- Types of values: https://hyperformula.handsontable.com/docs/guide/types-of-values.html
+
+## Always check `CellError` before using a result
+
+Cell values can be errors (`#DIV/0!`, `#VALUE!`, `#REF!`, etc.). Always test before using a result.
+
+```ts
+import { CellError, ErrorType } from 'hyperformula';
+
+const value = hf.getCellValue({ sheet: 0, col: 0, row: 0 });
+
+if (value instanceof CellError) {
+  // ErrorType enum: DIV_BY_ZERO, VALUE, REF, NAME, NUM, NA, CYCLE, ERROR
+  switch (value.type) {
+    case ErrorType.CYCLE:
+      console.log('Circular reference');
+      break;
+    case ErrorType.NAME:
+      // Usually: function not registered (check plugin registration or i18n language)
+      console.log('Unknown name:', value.message);
+      break;
+    default:
+      console.log('Error:', value.type, value.message);
+  }
+} else {
+  console.log('Value:', value);
+}
+```
+
+## `#CYCLE!` is HyperFormula-specific
+
+Standard spreadsheet apps report cycles differently. HyperFormula's `IF` also reports cycles for all branches, even unreachable ones — this can produce `#CYCLE!` in formulas that Excel or Sheets would evaluate.
+
+## Inspect value shape without catching errors
+
+```ts
+import { CellValueDetailedType } from 'hyperformula';
+
+hf.getCellValueDetailedType({ sheet: 0, col: 0, row: 0 });
+// → CellValueDetailedType.NUMBER | STRING | BOOLEAN | ERROR | EMPTY | ...
+```
+
+Use the detailed type when you need to distinguish e.g. number vs empty without touching the value.
+
+## Returning errors from custom functions
+
+Custom `FunctionPlugin` methods can return a `CellError` to surface a formula error. See [custom-functions.md](custom-functions.md) for the full pattern.
+
+```ts
+import { CellError, ErrorType } from 'hyperformula';
+
+return new CellError(ErrorType.DIV_BY_ZERO);
+```
+
+## Common causes
+
+| Error | Common cause |
+|---|---|
+| `#NAME?` | Function not registered (check `registerFunctionPlugin` order or `language` config) |
+| `#CYCLE!` | Circular reference — or an `IF` branch that *could* produce one |
+| `#REF!` | Deleted row/column broke a formula reference |
+| `#VALUE!` | Type mismatch — e.g. passing a string where a number is expected |
+| `#DIV/0!` | Division by zero, including empty cells coerced to 0 |
+| `#NUM!` | Out-of-range numeric result (e.g. `SQRT(-1)`) |
+| `#N/A` | Lookup miss (`MATCH`, `VLOOKUP`) or propagated from an upstream `#N/A` |

.agent/skills/hyperformula/references/general-pitfalls.md

@@ -0,0 +1,48 @@
+# General Pitfalls
+
+Cross-cutting gotchas that aren't tied to a specific API or config option. Authoritative docs:
+- Known limitations: https://hyperformula.handsontable.com/docs/guide/known-limitations.html
+- Built-in functions (full list): https://hyperformula.handsontable.com/docs/guide/built-in-functions.html
+- Runtime differences vs Excel/Sheets: https://hyperformula.handsontable.com/docs/guide/list-of-differences.html
+
+## Error handling
+
+See [error-handling.md](error-handling.md) — checking `CellError`, `ErrorType` enum, `getCellValueDetailedType`, common error causes.
+
+## Always call `destroy()` in long-running apps
+
+HyperFormula maintains internal data structures (dependency graph, address mapping) that are **not** garbage-collected until `destroy()` is called. Leaking instances in servers or SPAs accumulates memory.
+
+```ts
+hf.destroy();
+// After destroy() the instance is unusable — create a new one if needed.
+```
+
+v3.3 fixed two longstanding leak sources inside live instances — pending lazy transformations and undo/redo history were not being trimmed. If you maintain very long-lived instances with heavy mutation throughput, also see `maxPendingLazyTransformations` in [configuration.md](configuration.md) to bound the lazy-transformation queue. `destroy()` is still mandatory at teardown.
+
+## Force a string that looks like a formula
+
+Prefix with `'` (apostrophe) to store the literal text instead of evaluating.
+
+```ts
+// Stored as the literal string "=SUM(1,2)", not a formula:
+hf.setCellContents({ sheet: 0, col: 0, row: 0 }, "'=SUM(1,2)");
+```
+
+## Don't assume Excel parity
+
+~68% of Excel functions are covered. Runtime differences exist even for implemented functions. Before relying on behavior, check:
+
+- Full built-in list: https://hyperformula.handsontable.com/docs/guide/built-in-functions.html
+- Runtime differences: https://hyperformula.handsontable.com/docs/guide/list-of-differences.html
+
+## `licenseKey` is always required
+
+Every factory method (`buildFromArray`, `buildFromSheets`, `buildEmpty`) requires `licenseKey`. Use `'gpl-v3'` for open-source use or your commercial key.
+
+## Known hard limits
+
+- **Single workbook per instance** — no multi-workbook support.
+- No 3D references, dynamic arrays, async functions, structured references ("Tables"), or relative named expressions.
+- `IF` reports cycles for all branches, even unreachable ones.
+- Custom function result arrays don't auto-resize when dependencies change.

.agent/skills/hyperformula/references/getting-started.md

@@ -0,0 +1,82 @@
+# Getting Started
+
+Install, create an instance, read/write cells. Authoritative docs:
+- Client-side install: https://hyperformula.handsontable.com/docs/guide/client-side-installation.html
+- Server-side install: https://hyperformula.handsontable.com/docs/guide/server-side-installation.html
+- Basic usage: https://hyperformula.handsontable.com/docs/guide/basic-usage.html
+
+## Install
+
+### npm
+
+```bash
+npm install hyperformula
+```
+
+### CDN (jsDelivr, pinned version)
+
+```html
+<script src="https://cdn.jsdelivr.net/npm/hyperformula@3.2.0/dist/hyperformula.full.min.js"></script>
+```
+
+### Node.js
+
+Same npm install. Requires Node.js 13+ with full ICU for locale-aware string comparison.
+
+## Create an instance
+
+Every factory method requires `licenseKey`. Use `'gpl-v3'` for open-source use or your commercial key.
+
+### `buildFromArray` — single sheet from a 2D array
+
+```ts
+import { HyperFormula } from 'hyperformula';
+
+const hf = HyperFormula.buildFromArray(
+  [
+    ['10', '20', '=SUM(A1:B1)'],
+    ['30', '40', '=SUM(A2:B2)'],
+  ],
+  { licenseKey: 'gpl-v3' }
+);
+
+console.log(hf.getCellValue({ sheet: 0, col: 2, row: 0 })); // 30
+```
+
+### `buildFromSheets` — multi-sheet workbook
+
+```ts
+const hf = HyperFormula.buildFromSheets(
+  {
+    Revenue: [['100', '200', '=SUM(A1:B1)']],
+    Expenses: [['50', '=Revenue!C1 - A1']],
+  },
+  { licenseKey: 'gpl-v3' }
+);
+```
+
+Cross-sheet references use `SheetName!CellRef` syntax.
+
+### `buildEmpty` — start empty, add sheets later
+
+```ts
+const hf = HyperFormula.buildEmpty({ licenseKey: 'gpl-v3' });
+const sheetName = hf.addSheet('Data');
+const sheetId = hf.getSheetId(sheetName);
+
+hf.setCellContents({ sheet: sheetId, col: 0, row: 0 }, [
+  ['10', '20', '=SUM(A1:B1)'],
+]);
+```
+
+## Cell addresses
+
+All addresses use zero-indexed `{ sheet, col, row }`. Convert to/from A1 notation with built-in helpers:
+
+```ts
+hf.simpleCellAddressFromString('B3', 0);
+// → { sheet: 0, col: 1, row: 2 }
+
+hf.simpleCellAddressToString({ sheet: 0, col: 1, row: 2 }, 0);
+// → 'B3'
+```

.agent/skills/hyperformula/references/vue3.md

@@ -0,0 +1,72 @@
+# Vue 3
+
+HyperFormula + Vue 3 integration. Authoritative doc:
+- Vue integration guide: https://hyperformula.handsontable.com/docs/guide/integration-with-vue.html
+
+## Always wrap the instance with `markRaw`
+
+Vue 3's Composition API wraps objects in a reactive Proxy that intercepts property access and **corrupts HyperFormula's internal state**, causing silent data corruption or crashes. React, Angular, and Svelte need no special handling.
+
+```ts
+import { markRaw } from 'vue';
+import { HyperFormula } from 'hyperformula';
+
+const hf = markRaw(
+  HyperFormula.buildEmpty({ licenseKey: 'gpl-v3' })
+);
+```
+
+Use the same wrapper no matter where the instance is held — `ref`, `reactive`, component