Add ability to serve LLM markdown during local development

Author: reakaleek

src/Elastic.Markdown/DocumentationGenerator.cs

@@ -15,6 +15,8 @@
 using Elastic.Markdown.Exporters;
 using Elastic.Markdown.IO;
 using Elastic.Markdown.Links.CrossLinks;
+using Elastic.Markdown.Myst.Renderers;
+using Elastic.Markdown.Myst.Renderers.LlmMarkdown;
 using Markdig.Syntax;
 using Microsoft.Extensions.Logging;
 
@@ -340,6 +342,19 @@ private async Task GenerateDocumentationState(Cancel ctx)
 		await DocumentationSet.OutputDirectory.FileSystem.File.WriteAllBytesAsync(stateFile.FullName, bytes, ctx);
 	}
 
+	public async Task<string> RenderLlmMarkdown(MarkdownFile markdown, Cancel ctx)
+	{
+		await DocumentationSet.Tree.Resolve(ctx);
+		var document = await markdown.ParseFullAsync(ctx);
+		await using var writer = new StringWriter();
+		var renderer = new LlmMarkdownRenderer(writer)
+		{
+			BuildContext = DocumentationSet.Context
+		};
+		_ = renderer.Render(document);
+		return writer.ToString().Trim();
+	}
+
 	public async Task<RenderResult> RenderLayout(MarkdownFile markdown, Cancel ctx)
 	{
 		await DocumentationSet.Tree.Resolve(ctx);

src/Elastic.Markdown/HtmlWriter.cs

@@ -11,6 +11,8 @@
 using Elastic.Documentation.Site.Navigation;
 using Elastic.Markdown.Extensions.DetectionRules;
 using Elastic.Markdown.IO;
+using Elastic.Markdown.Myst.Renderers;
+using Elastic.Markdown.Myst.Renderers.LlmMarkdown;
 using Elastic.Markdown.Page;
 using Markdig.Syntax;
 using RazorSlices;

src/tooling/docs-builder/Http/DocumentationWebHost.cs

@@ -10,7 +10,10 @@
 using Elastic.Documentation.Configuration.Versions;
 using Elastic.Documentation.Site.FileProviders;
 using Elastic.Documentation.Tooling;
+using Elastic.Markdown.Exporters;
 using Elastic.Markdown.IO;
+using Elastic.Markdown.Myst.Renderers;
+using Markdig.Syntax;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Http;
@@ -187,6 +190,17 @@ private static async Task<IResult> ServeDocumentationFile(ReloadableGeneratorSta
 	{
 		var generator = holder.Generator;
 		const string navPartialSuffix = ".nav.html";
+
+		// Check if the original request is asking for LLM-rendered markdown
+		var requestLlmMarkdown = slug.EndsWith(".md");
+		var originalSlug = slug;
+
+		// If requesting .md output, remove the .md extension to find the source file
+		if (requestLlmMarkdown)
+		{
+			slug = slug[..^3]; // Remove ".md" extension
+		}
+
 		if (slug.EndsWith(navPartialSuffix))
 		{
 			var segments = slug.Split("/");
@@ -218,8 +232,18 @@ private static async Task<IResult> ServeDocumentationFile(ReloadableGeneratorSta
 		switch (documentationFile)
 		{
 			case MarkdownFile markdown:
-				var rendered = await generator.RenderLayout(markdown, ctx);
-				return Results.Content(rendered.Html, "text/html");
+				if (requestLlmMarkdown)
+				{
+					// Render using LLM pipeline for CommonMark output
+					var llmRendered = await generator.RenderLlmMarkdown(markdown, ctx);
+					return Results.Content(llmRendered, "text/markdown; charset=utf-8");
+				}
+				else
+				{
+					// Regular HTML rendering
+					var rendered = await generator.RenderLayout(markdown, ctx);
+					return Results.Content(rendered.Html, "text/html");
+				}
 
 			case ImageFile image:
 				return Results.File(image.SourceFile.FullName, image.MimeType);