Thanks to the Twoslash integration of Shiki, the default code syntax highlighter, it is as simple as adding a transformer.
npm install fumadocs-twoslash
Add to your Shiki transformers.
Example for Fumadocs MDX
import createMDX from 'fumadocs-mdx/config';
import { rehypeCodeDefaultOptions } from 'fumadocs-core/mdx-plugins';
import { transformerTwoslash } from 'fumadocs-twoslash';
 
/** @type {import('next').NextConfig} */
const withMDX = createMDX({
  mdxOptions: {
    rehypeCodeOptions: {
      transformers: [
        ...rehypeCodeDefaultOptions.transformers,
        transformerTwoslash(),
      ],
    },
  },
});
 
export default withMDX(config);
Add stylings and components.
import 'fumadocs-ui/twoslash.css';
import { Popup, PopupContent, PopupTrigger } from 'fumadocs-ui/twoslash/popup';
 
const mdxComponents = {
  Popup,
  PopupContent,
  PopupTrigger,
};
Learn more about Twoslash notations.
console.g- group
- groupCollapsed
- groupEnd
;
 
 
 
 
 
const player: Player = { name: 'Hello World' };
const a = '123';
 
console.log(a);
 
import { generateFiles } from 'fumadocs-openapi';
 
void generateFiles({
  input: ['./museum.yaml'],
  output: './content/docs/ui',
});
const a = '123';
 a = 132;Cannot assign to 'a' because it is a constant.
 
const b = 1;
 const c = 1;
 const d = 1;
 Custom annotation message