Class Reference

Tag Helper

<richtextbox> Attributes

All attributes available on the <richtextbox> tag helper element.

Core

Attribute	Type	Default	Description
id	string	auto	HTML element ID for the editor instance
name	string	required	Form field name for the HTML content
asp-for	expression	-	Model expression for two-way binding
html	string	empty	Initial HTML content for the editor
class	string	-	CSS class for the editor wrapper element

Toolbar

Attribute	Type	Default	Description
toolbar	string	"default"	Toolbar preset: default, full, basic, ribbon, office, or a custom button string
toolbar-mobile	string	"mobile"	Toolbar layout for mobile-width screens

Appearance

Attribute	Type	Default	Description
skin	string	"default"	Visual skin: default, gray, office2007blue, rounded-corner, blue
width	string	"100%"	Editor width (CSS value: px, %, em)
height	string	"300px"	Editor height (CSS value)
resize-mode	string	"both"	Resize mode: both, height, none

Content Behavior

Attribute	Type	Default	Description
paste-mode	string	"Auto"	Paste handling: Auto, Text, Word, Disabled
enter-key-tag	string	"p"	Tag for Enter key: p, div, br
url-type	string	"default"	URL processing: default, relative, absolute
read-only	bool	false	Makes the editor read-only

Context Menu

Attribute	Type	Default	Description
enable-context-menu	bool	false	Enable custom right-click context menu
context-menu-mode	string	"Default"	Menu preset: Default, Simple, Minimal

Statistics & UI

Attribute	Type	Default	Description
show-tag-list	bool	true	Show tag path in the bottom bar
show-statistics	bool	true	Show character/word statistics in the bottom bar

Content Styling

Attribute	Type	Default	Description
content-css-url	string	built-in	URL of a CSS file applied to the content area
content-css-text	string	""	Inline CSS text applied to the content area
preview-css-url	string	built-in	CSS file for the preview window
editor-body-css-class	string	""	CSS class applied to the editor body element
editor-body-css-text	string	""	Inline CSS for the editor body element

Dialog Data

Attribute	Type	Default	Description
image-items-json	string	[]	JSON array of image URLs for the insert image dialog
gallery-images-json	string	[]	JSON array of {url, text} objects for the gallery
html-templates-json	string	[]	JSON array of [name, html] arrays for templates

Autosave

Attribute	Type	Default	Description
auto-save	bool	false	Enable localStorage draft saving
auto-save-key	string	auto	localStorage key for draft isolation
auto-save-delay	int	600	Delay in milliseconds between saves

Validation

Attribute	Type	Default	Description
max-html-length	int	0 (unlimited)	Maximum total HTML characters
max-text-length	int	0 (unlimited)	Maximum visible text characters

Services

AddRichTextBox() Options

Configure the RichTextBox services in Program.cs.

Property	Type	Default	Description
UploadWebPath	string	"/uploads"	Web-accessible path for uploaded files
MaxUploadBytes	long	4194304	Maximum upload file size (4 MB default)
AllowedImageExtensions	string[]	.jpg .png .gif .webp .svg	Allowed image file extensions
AllowedFileExtensions	string[]	.zip .pdf .doc .docx .rtf .txt	Allowed non-image file extensions
RequireValidLicense	bool	true	Require valid license file
LicenseNumber	string	"30076785"	Expected license number

JavaScript

execCommand Reference

Commands available via editor.execCommand(commandName).

Formatting

bold, italic, underline, strike, superscript, subscript, removeformat, formatpainter, changecase

Font & Color

fontname, fontsize, forecolor, backcolor, lineheight, paragraphs, inlinestyle

Alignment

justifyleft, justifycenter, justifyright, justifyfull, ltr, rtl

Lists & Structure

insertorderedlist, insertunorderedlist, indent, outdent, insertblockquote, inserthorizontalrule, inserttable

Links & Media

insertlink, unlink, insertimage, insertgallery, insertvideo, insertdocument, insertanchor, insertimagemap

Insert

insertemoji, insertchars, insertcode, inserttemplate, insertdate, insertbox, insertlayer, insertfieldset

Clipboard

cut, copy, paste, pastetext, pasteword, delete, selectall

View & Tools

code, preview, find, print, fullscreenenter, fullscreenexit, toggleborder, togglemore, help

History

undo, redo, newdoc, save, load, cleancode

AI Toolkit

editor.aiToolkit methods

Enable with enable-ai-toolkit="true". The toolkit namespace hangs off every editor instance at editor.aiToolkit.

Method	Description
setResolver(fn)	Swap the Ask AI / AI Chat resolver (BYOK). Pass `null` to restore the demo resolver.
openDialog(options)	Open the Ask AI dialog. `options.presetMode` pre-selects a quick action.
openChatPanel(options)	Show the docked AI Chat panel; `options.focusComposer` moves caret to the textarea.
openReviewPanel()	Open the AI Review drawer with pending / accepted / rejected suggestions.
runQuickAction(id)	Run a built-in quick action by id (`proofread`, `rewrite`, `shorten`, `expand`, `summarize`, `translate`, `justify`).
getSuggestions()	Return the current pending-suggestions array.
clearSuggestions()	Remove all pending suggestions from the drawer.
saveSuggestionLedger() / loadSuggestionLedger()	Persist or restore the local suggestion ledger.
loadRemoteSuggestionLedger() / refreshRemoteReviewState()	Sync the drawer with a server-backed review log.

Structured content bridge

window.RichTextEditorStructuredContent

Enable with enable-structured-content="true". The editor gains getJSON() / setJSON(), and the following global helpers become available:

Member	Description
editor.getJSON()	Export the current document as a semantic JSON value.
editor.setJSON(value)	Replace the editor document with a semantic JSON value.
fromMarkdown(md)	Parse Markdown to a semantic JSON document.
toMarkdown(value)	Render a semantic JSON document (or editor HTML) to Markdown.
renderHTML(value)	Produce sanitized static HTML without mounting a live editor.
validateStructuredContent(value)	Return `{ valid, issues[] }` against the structured-content schema.
parseStructuredContentHtml(html)	Parse an HTML fragment into the semantic JSON model.
serializeStructuredContent(value)	Serialize a semantic JSON document back to an HTML fragment.

Endpoints

MapRichTextBoxUploads()

Maps the following endpoints in your ASP.NET Core application:

Endpoint	Method	Description
/richtextbox/upload	POST	Upload images and files
/richtextbox/gallery	GET/POST	Browse folders, list images, create folders