Plugin Package API

Each optional NuGet package exposes one parameterless IMarkdownPlugin entry point. Add instances to the same plugin collection supplied to MarkdownRenderingServices.CreateController and CreateEditingService.

IMarkdownPlugin[] plugins =
[
    new AlertsMarkdownPlugin(),
    new MathMarkdownPlugin()
];

markdown.RenderController = MarkdownRenderingServices.CreateController(plugins);
markdown.EditingService = MarkdownRenderingServices.CreateEditingService(plugins);

For package installation, syntax, behavior, and combination examples, see Plugin Ecosystem.

Package entry points

NuGet package	Namespace	Public plugin class	Registered capabilities
`ProMarkdown.Plugin.Alerts`	`ProMarkdown.Plugin.Alerts`	`AlertsMarkdownPlugin`	Alert block renderer, template provider, editor
`ProMarkdown.Plugin.CustomContainers`	`ProMarkdown.Plugin.CustomContainers`	`CustomContainersMarkdownPlugin`	Container block renderer, template provider, editor
`ProMarkdown.Plugin.DefinitionLists`	`ProMarkdown.Plugin.DefinitionLists`	`DefinitionListMarkdownPlugin`	Definition-list renderer, template provider, editor
`ProMarkdown.Plugin.Figures`	`ProMarkdown.Plugin.Figures`	`FiguresMarkdownPlugin`	Figure renderer, template provider, editor
`ProMarkdown.Plugin.Footers`	`ProMarkdown.Plugin.Footers`	`FootersMarkdownPlugin`	Footer renderer, template provider, editor
`ProMarkdown.Plugin.Math`	`ProMarkdown.Plugin.Math`	`MathMarkdownPlugin`	Block and inline math renderers, template provider, block and inline editors
`ProMarkdown.Plugin.Mermaid`	`ProMarkdown.Plugin.Mermaid`	`MermaidMarkdownPlugin`	Parser, diagram renderer, template provider, editor
`ProMarkdown.Plugin.SyntaxHighlighting`	`ProMarkdown.Plugin.SyntaxHighlighting`	`SyntaxHighlightingMarkdownPlugin`	Built-in code-block renderer
`ProMarkdown.Plugin.TextMate`	`ProMarkdown.Plugin.TextMate`	`TextMateMarkdownPlugin`	TextMate code renderer and AvaloniaEdit code editor

Every plugin class has a public parameterless constructor and this method:

public void Register(MarkdownPluginRegistry registry);

Registration is normally performed by the service factories. Call Register directly only when assembling a MarkdownPluginRegistry yourself.

Stable editor identifiers

Use these public constants when selecting a preferred editor:

Type	Constant	Feature
`AlertsMarkdownEditorIds`	`Block`	`Alert`
`CustomContainerMarkdownEditorIds`	`Block`	`CustomContainer`
`DefinitionListMarkdownEditorIds`	`Block`	`DefinitionList`
`FiguresMarkdownEditorIds`	`Block`	`Figure`
`FooterMarkdownEditorIds`	`Block`	`Footer`
`MathMarkdownEditorIds`	`Block`	block `Math`
`MathMarkdownEditorIds`	`Inline`	inline `Math`
`MermaidMarkdownPlugin`	`MermaidEditorId`	`Mermaid`
`TextMateMarkdownPlugin`	`TextMateCodeEditorId`	`Code`

Example:

markdown.EditorPreferences
    .PreferEditor(
        MarkdownEditorFeature.Math,
        MathMarkdownEditorIds.Inline)
    .PreferEditor(
        MarkdownEditorFeature.Code,
        TextMateMarkdownPlugin.TextMateCodeEditorId);

SyntaxHighlightingMarkdownPlugin is rendering-only and does not expose an editor ID.

Mermaid public API

MermaidMarkdownPlugin also supports host configuration and renderer injection:

public MermaidMarkdownPlugin(MermaidMarkdownPluginOptions options);
public MermaidMarkdownPlugin(
    IMermaidSvgRenderer renderer,
    MermaidMarkdownPluginOptions? options = null);

IMermaidSvgRenderer.RenderAsync receives a MermaidSvgRenderRequest with Source, a background-thread-safe Palette snapshot, FontFamily, and FontSize, plus the render cancellation token. The plugin sanitizes returned SVG before displaying it.

MermaidMarkdownPluginOptions has init-only AccessibleName, ErrorText, RetryText, and optional ActivateLinkAsync properties. Link activation is restricted to absolute HTTPS URIs even when a callback is supplied.

MermaidDiagramControl is a public, styleable TemplatedControl created by the plugin. It exposes the styled ThemePalette property and read-only direct properties for IsLoading, HasImage, HasError, ErrorText, SourceText, SourceFontSize, RetryText, and RetryCommand. The control owns its SVG resources and implements IDisposable; normal plugin rendering registers it with the render resource tracker automatically.

Composition notes

Plugin classes retain any resources they reuse across renders; construct them once and reuse the plugin list.
TextMateMarkdownPlugin has a lower renderer order than SyntaxHighlightingMarkdownPlugin, so TextMate gets the first opportunity. It returns false for unsupported language hints and Mermaid aliases, allowing a later renderer to handle the block.
MermaidMarkdownPlugin recognizes mermaid, mmd, mermaidjs, and diagram-mermaid fenced language aliases as well as its documented custom-container form.
Stable editor constants are API identifiers. Display labels, visual styling, and internal renderer/editor implementation types are not public contracts.