I think you could do so in the line below, and the plugins exist for it, I think: Line: https://github.com/Joeyonng/react-jupyter-notebook/blob/deddebcce78180818ba0d8479edf09f86f42f9ed/src/lib/BlockSource.tsx#L110 Plugins: https://github.com/mdx-js/mdx/tree/main/packages/remark-mdx, https://github.com/elviswolcott/remark-admonitions