MDX: Include frontmatter into page.data.content by default

fuma-nama · fuma-nama · commit c8f49d891a35 · 2025-08-19T22:15:07.000+08:00
diff --git a/.changeset/dark-shirts-relate.md b/.changeset/dark-shirts-relate.md
@@ -0,0 +1,5 @@
+---
+'fumadocs-mdx': patch
+---
+
+Include frontmatter into `page.data.content` by default
diff --git a/apps/docs/content/docs/ui/(integrations)/get-llm-text.ts b/apps/docs/content/docs/ui/(integrations)/get-llm-text.ts
@@ -17,10 +17,9 @@ export async function getLLMText(page: InferPageType<typeof source>) {
     value: page.data.content,
   });
 
+  // note: it doesn't escape frontmatter, it's up to you.
   return `# ${page.data.title}
 URL: ${page.url}
 
-${page.data.description}
-
 ${processed.value}`;
 }
diff --git a/packages/mdx/src/map/generate.ts b/packages/mdx/src/map/generate.ts
@@ -132,7 +132,7 @@ export async function generateJS(
         info: file,
         lastModified,
         data: data as Record<string, unknown>,
-        content: parsed.content,
+        content: { body: parsed.content, matter: parsed.matter },
       } satisfies AsyncRuntimeFile);
     });
 
diff --git a/packages/mdx/src/runtime/async.ts b/packages/mdx/src/runtime/async.ts
@@ -26,10 +26,12 @@ export const _runtimeAsync: RuntimeAsync = {
       return {
         ...data,
         _file: file,
-        content,
+        get content() {
+          return `${content.matter}${content.body}`;
+        },
         async load() {
           const mdxOptions = await initMdxOptions;
-          const out = await buildMDX(collection, content, {
+          const out = await buildMDX(collection, content.body, {
             ...mdxOptions,
             development: false,
             frontmatter: data as Record<string, unknown>,
diff --git a/packages/mdx/src/runtime/types.ts b/packages/mdx/src/runtime/types.ts
@@ -39,7 +39,7 @@ export interface RuntimeFile {
 export interface AsyncRuntimeFile {
   info: FileInfo;
   data: Record<string, unknown>;
-  content: string;
+  content: { matter: string; body: string };
   lastModified?: Date;
 }
 
diff --git a/packages/mdx/src/utils/fuma-matter.ts b/packages/mdx/src/utils/fuma-matter.ts
@@ -4,6 +4,9 @@
 import { load } from 'js-yaml';
 
 interface Output {
+  /**
+   * The matter section, including the delimiter.
+   */
   matter: string;
   content: string;
   data: unknown;
@@ -22,10 +25,10 @@ export function fumaMatter(input: string): Output {
   }
 
   // get the raw front-matter block
-  output.matter = match[1];
+  output.matter = match[0];
   output.content = input.slice(match[0].length);
 
-  const loaded = load(output.matter);
+  const loaded = load(match[1]);
   output.data = loaded ?? {};
 
   return output;
diff --git a/packages/mdx/test/fixtures/index-async.output.js b/packages/mdx/test/fixtures/index-async.output.js
@@ -3,4 +3,4 @@ import { _runtimeAsync, buildConfig } from "fumadocs-mdx/runtime/async"
 const _sourceConfig = buildConfig(_source)
 import { _runtime } from "fumadocs-mdx"
 import * as _source from "./config"
-export const docs = _runtimeAsync.doc<typeof _source.docs>([{"info":{"path":"index.mdx","absolutePath":"$cwd/packages/mdx/test/fixtures/index.mdx"},"data":{},"content":"# Hello World\n"}, {"info":{"path":"folder/test.mdx","absolutePath":"$cwd/packages/mdx/test/fixtures/folder/test.mdx"},"data":{},"content":""}], "docs", _sourceConfig)
+export const docs = _runtimeAsync.doc<typeof _source.docs>([{"info":{"path":"index.mdx","absolutePath":"$cwd/packages/mdx/test/fixtures/index.mdx"},"data":{},"content":{"body":"# Hello World\n","matter":""}}, {"info":{"path":"folder/test.mdx","absolutePath":"$cwd/packages/mdx/test/fixtures/folder/test.mdx"},"data":{},"content":{"body":"","matter":""}}], "docs", _sourceConfig)
diff --git a/packages/mdx/test/index.test.ts b/packages/mdx/test/index.test.ts
@@ -93,8 +93,11 @@ test('parse frontmatter', () => {
         "description": "I love Fumadocs",
         "title": "hello world",
       },
-      "matter": "title: hello world
-    description: I love Fumadocs",
+      "matter": "---
+    title: hello world
+    description: I love Fumadocs
+    ---
+    ",
     }
   `);
 
@@ -109,8 +112,11 @@ test('parse frontmatter', () => {
         "description": "I love Fumadocs",
         "title": "hello world",
       },
-      "matter": "title: hello world
-    description: I love Fumadocs",
+      "matter": "---
+    title: hello world
+    description: I love Fumadocs
+    ---
+    ",
     }
   `);
 

-Original file line number
+Diff line change
@@ @@ -0,0 +1,5 @@ @@
 +---
 +'fumadocs-mdx': patch
 +---
++
 +Include frontmatter into `page.data.content` by default
Original file line number	Diff line number	Diff line change
`@@ -39,7 +39,7 @@ export interface RuntimeFile {`
`39`	`39`	`export interface AsyncRuntimeFile {`
`40`	`40`	`info: FileInfo;`
`41`	`41`	`data: Record<string, unknown>;`
`42`		`- content: string;`
	`42`	`+ content: { matter: string; body: string };`
`43`	`43`	`lastModified?: Date;`
`44`	`44`	`}`
`45`	`45`