# @vuepress/markdown > markdown library for vuepress ## Public API ### PLUGINS A map [constant](./lib/constant.js) containing the names of all built-in markdown-it plugins. ### isRequiredPlugin(pluginName: string) - **Usage**: ```js const { isRequiredPlugin } = require('@vuepress/markdown') console.log(isRequiredPlugin(PLUGINS.COMPONENT)) // true console.log(isRequiredPlugin(PLUGINS.HIGHLIGHT_LINES)) // false ``` ### removePlugin(config: chainMarkdown, pluginName: string) Remove the specified built-in markdown-it plugin in VuePress. It's needed to use with VuePress's [Plugin API > chainMarkdown](https://vuepress.vuejs.org/plugin/option-api.html#chainmarkdown). - **Usage**: ```js // Your VuePress Plugin or site config. const { removePlugin } = require('@vuepress/markdown') module.exports = { chainMarkdown (config) { removePlugin(config, PLUGINS.HIGHLIGHT_LINES) } } ``` > Note that `PLUGINS.COMPONENT` and `PLUGINS.ANCHOR` are required in VuePress, It is forbidden to delete them! ### removeAllBuiltInPlugins(config: chainMarkdown) Remove all built-in but not 100% necessary markdown-it plugins in VuePress. - **Usage**: ```js // Your VuePress Plugin or site config. module.exports = { chainMarkdown (config) { require('@vuepress/markdown').removeAllBuiltInPlugins(config) } } ```