# Features and installation

Choose built-in packages, optional syntax, editing commands and host responsibilities.

## Base composition

`@quirekit/msfe-core` provides editor and extension contracts. StarterKit groups common Markdown behavior. Vue / React adapters retain the application's Provider tree. Pin compatible package versions together; the public API remains experimental.

~~~ts
import { StarterKit } from '@quirekit/msfe-starter-kit'
import { CustomContainer, Footnotes, Math, Mermaid } from '@quirekit/msfe-markdown-extras'
const extensions = [StarterKit, CustomContainer, Footnotes, Math, Mermaid]
~~~

Configure themes, UI and language support through the relevant guides. You do not need every optional package to start.

## StarterKit features

| Feature | Source forms | Editing entry |
| --- | --- | --- |
| Headings | ATX / Setext | `setHeading(level)` |
| Bold, emphasis, strikethrough | `**bold**`, `*em*`, `~~del~~` | Corresponding toggle commands |
| Inline and block code | Spans, fences, indented code | Language command and native source editing |
| Links and images | Inline / resolved references | Insert commands and supported field patches |
| Lists and tasks | Ordered, unordered, task syntax | Indent, outdent, continue and task controls |
| Quotes and thematic rules | `>` and separators | Native source and presentation |
| GFM tables | Pipe tables | Row/column commands and native cell text |
| Literals | Escapes, entities, breaks | Source-neutral presentation |

Readable or renderable forms do not all support identical field writes. Check `can()`, semantic queries and codec support before calling arbitrary attribute updates.

## Table and list commands

~~~ts
editor.commands.insertTableRow('after')
editor.commands.insertTableColumn('before')
editor.commands.moveTableCell(1)
editor.commands.deleteTableRow()
editor.commands.indentList()
~~~

Related `@quirekit/msfe-prose` features install these commands. Selection must identify an applicable structure; deleting the last row or column has constraints. Tables remain GFM source, not arbitrary rich-text block containers. See [Commands](/en/guide/commands).

## Optional Markdown features

These exports come from `@quirekit/msfe-markdown-extras` and are not all included in StarterKit.

| Extension | Syntax | Boundary |
| --- | --- | --- |
| `Frontmatter` | Leading YAML fence | Source presentation, not a business configuration form |
| `DocumentProperties` | Optional YAML property table, requires `Frontmatter` | Explicit installation; source mode preserves the header; can be disabled on the same instance |
| `Subscript` / `Superscript` | `H~2~O` / `x^2^` | Distinct from strikethrough; unconfirmed forms retain source |
| `InsertedText` / `Highlight` | `++added++` / `==marked==` | Supply corresponding theme styles |
| `Emoji` | `:smile:` / optional emoticons | Unicode output; configurable definitions |
| `DefinitionList` | Term followed by `: definition` | Markdown owns the body |
| `Abbreviations` | `*[HTML]: Hyper Text Markup Language` | Source and lookup index stay separate |
| `Footnotes` | References, definitions, inline notes | Source-derived numbering, query and navigation |
| `Typographer` | Quote and punctuation display | Source-neutral; configurable quotes and work bounds |
| `Callout` | Quote with `[!NOTE]` | Role styling, distinct from colon containers |
| `CustomContainer` | `::: warning` | Registered types, nesting and disclosure; see [Containers](/en/extensions/containers) |
| `Math` | `$...$` and `$$...$$` | KaTeX preview with source fallback; no structured math commands |
| `Mermaid` | `mermaid` fences | Optional asynchronous preview; see [Diagrams](/en/extensions/diagrams) |

~~~ts
import { Emoji, Typographer, Footnotes } from '@quirekit/msfe-markdown-extras'
const emoji = Emoji.configure({ definitions: { ship: '🚢' }, emoticons: false })
const typography = Typographer.configure({ smartQuotes: true, quotes: ['“', '”', '‘', '’'] })
const footnotes = Footnotes.configure({
  referenceLabel: number => `Footnote ${number}`,
  definitionLabel: number => `Back to footnote ${number}`,
})
~~~

Load KaTeX CSS, for example `katex/dist/katex.min.css`, from the host's global CSS entry. Math and Mermaid accept host preview controls.

Advanced footnote access uses `queryFootnotes()` and `navigateFootnote()`; abbreviations use `queryAbbreviations()`. Queries may be pending. Reuse their indexes and never treat display numbers as permanent IDs.

## HTML is separate

`@quirekit/msfe-html` exports `Html`, defaulting to source. `Html.configure({ rendering: 'safe' })` enables restricted sanitized presentation. Image loading additionally needs explicit `allowImage`. Scripts, arbitrary HTML editing and unrestricted embedded/browser HTML layout are outside its promise.

Adjust the preference through the package's public functions without rewriting Markdown. Unsupported structures retain source.

## Host responsibilities

Storage, files, uploads, routing, permissions, navigation, HTML/PDF export and Yjs integration belong to the host. `applyChanges` validates revisions but is not a collaboration adapter. markdown-it, ProseMirror and Tiptap plugins cannot install directly; see [Markdown plugins](/en/extensions/markdown-plugins).

Continue with [nodes](/en/extensions/custom-node), [containers](/en/extensions/containers), [diagrams](/en/extensions/diagrams), [themes](/en/customization/theme) or [saving](/en/guide/saving).