Rollup and Rolldown

ironmark/rollup works in Rollup 4.24+ and Rolldown.

// rollup.config.js / rolldown.config.js
import ironmarkMdx from "ironmark/rollup";
 
export default {
  input: "src/main.jsx",
  plugins: [ironmarkMdx()],
};

• Rolldown compiles the JSX itself; the plugin marks the module as JSX.
• Rollup has no JSX transform enabled by default. The plugin turns on Rollup's built-in transform (jsx: { mode: "automatic" }, with your jsxImportSource) unless your config already sets jsx.

If you set jsx yourself, use the automatic runtime, or add a JSX plugin such as @rollup/plugin-babel after ironmarkMdx().

See options for everything the plugin accepts.