Add rendered HTML content support via Accept header

This commit adds support for retrieving rendered HTML content from markdown files using the Accept header: application/vnd.olrapi.note+html

Changes:
- Added ContentTypes.olrapiNoteHtml constant
- Implemented renderMarkdownToHtml() method using Obsidian's MarkdownRenderer API
- Updated _vaultGet() to handle HTML content type requests
- Updated OpenAPI documentation with new content format
- Added proper component lifecycle management to prevent memory leaks

The feature integrates with Obsidian's native rendering pipeline, ensuring:
- Wiki-links are converted to HTML anchors
- Plugin integrations (Metadata Menu, etc.) are preserved
- Callouts, embeds, and other Obsidian-specific markdown is properly rendered
- Syntax highlighting for code blocks

This is backward compatible and uses standard HTTP content negotiation.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: papertray3

docs/src/lib/get.jsonnet

@@ -15,6 +15,13 @@
             '$ref': '#/components/schemas/NoteJson',
           },
         },
+        'application/vnd.olrapi.note+html': {
+          schema: {
+            type: 'string',
+            description: 'Rendered HTML content from the markdown file',
+            example: '<h1>This is my document</h1>\n<p>something else here</p>\n',
+          },
+        },
       },
     },
     '404': {

docs/src/openapi.jsonnet

@@ -131,7 +131,7 @@ std.manifestYamlDoc(
         get: Get {
           tags: ['Active File'],
           summary: 'Return the content of the active file open in Obsidian.\n',
-          description: 'Returns the content of the currently active file in Obsidian.\n\nIf you specify the header `Accept: application/vnd.olrapi.note+json`, will return a JSON representation of your note including parsed tag and frontmatter data as well as filesystem metadata.  See "responses" below for details.\n',
+          description: 'Returns the content of the currently active file in Obsidian.\n\nContent format options via Accept header:\n- `Accept: application/vnd.olrapi.note+json` - Returns a JSON representation including parsed tag and frontmatter data as well as filesystem metadata\n- `Accept: application/vnd.olrapi.note+html` - Returns rendered HTML from markdown files\n- Default - Returns raw file content\n\nSee "responses" below for details.\n',
         },
         put: Put {
           tags: [
@@ -166,7 +166,7 @@ std.manifestYamlDoc(
             'Vault Files',
           ],
           summary: 'Return the content of a single file in your vault.\n',
-          description: 'Returns the content of the file at the specified path in your vault should the file exist.\n\nIf you specify the header `Accept: application/vnd.olrapi.note+json`, will return a JSON representation of your note including parsed tag and frontmatter data as well as filesystem metadata.  See "responses" below for details.\n',
+          description: 'Returns the content of the file at the specified path in your vault should the file exist.\n\nContent format options via Accept header:\n- `Accept: application/vnd.olrapi.note+json` - Returns a JSON representation including parsed tag and frontmatter data as well as filesystem metadata\n- `Accept: application/vnd.olrapi.note+html` - Returns rendered HTML from markdown files\n- Default - Returns raw file content\n\nSee "responses" below for details.\n',
           parameters+: [ParamPath],
         },
         put: Put {

src/constants.ts

@@ -51,6 +51,7 @@ export enum ContentTypes {
   json = "application/json",
   markdown = "text/markdown",
   olrapiNoteJson = "application/vnd.olrapi.note+json",
+  olrapiNoteHtml = "application/vnd.olrapi.note+html",
   jsonLogic = "application/vnd.olrapi.jsonlogic+json",
   dataviewDql = "application/vnd.olrapi.dataview.dql+txt",
 }

src/requestHandler.ts

@@ -3,6 +3,8 @@ import {
   App,
   CachedMetadata,
   Command,
+  Component,
+  MarkdownRenderer,
   PluginManifest,
   prepareSimpleSearch,
   TFile,
@@ -205,6 +207,30 @@ export default class RequestHandler {
     };
   }
 
+  async renderMarkdownToHtml(
+    markdown: string,
+    sourcePath: string
+  ): Promise<string> {
+    const component = new Component();
+    component.load();
+
+    // Create a temporary div to render into
+    const renderDiv = document.createElement("div");
+
+    await MarkdownRenderer.render(
+      this.app,
+      markdown,
+      renderDiv,
+      sourcePath,
+      component
+    );
+
+    const html = renderDiv.innerHTML;
+    component.unload();
+
+    return html;
+  }
+
   getResponseMessage({
     statusCode = 400,
     message,
@@ -329,6 +355,23 @@ export default class RequestHandler {
           return;
         }
 
+        if (req.headers.accept === ContentTypes.olrapiNoteHtml) {
+          const file = this.app.vault.getAbstractFileByPath(path) as TFile;
+          if (file && mimeType === ContentTypes.markdown) {
+            const markdown = await this.app.vault.cachedRead(file);
+            const html = await this.renderMarkdownToHtml(markdown, path);
+            res.setHeader("Content-Type", ContentTypes.olrapiNoteHtml);
+            res.send(html);
+            return;
+          } else {
+            this.returnCannedResponse(res, {
+              statusCode: 400,
+              message: "Rendered HTML is only available for markdown files",
+            });
+            return;
+          }
+        }
+
         res.send(Buffer.from(content));
       } else {
         this.returnCannedResponse(res, {