# Slots > Add components at fixed places of the layout, without replacing anything. Source: https://aymericchaverot.github.io/zenith-docs/customization/slots/ [Component overrides](/customization/overrides/) replace a whole piece of the layout. Most of the time you only want to add something: an announcement above the header, a link at the bottom of the sidebar, a feedback prompt under each page. Slots do that, and keep every built-in component in place. ```js title="astro.config.mjs" zenith({ title: 'My Docs', slots: { banner: './src/components/Announcement.astro', sidebarBottom: ['./src/components/Sponsor.astro', './src/components/Status.astro'], }, }); ``` A slot takes one component, or several rendered in order. The link at the bottom of this sidebar is one. ## Available slots | Slot | Where | | --------------- | ------------------------------------------------------ | | `head` | At the end of ``, for extra meta tags or scripts | | `banner` | Above the header, across the whole page | | `headerEnd` | After the last action of the header | | `sidebarTop` | Above the page tree, below the section tabs | | `sidebarBottom` | Below the page tree | | `contentBefore` | Between the title and the content of the page | | `contentAfter` | After the content, before the page footer | | `tocAfter` | Under the table of contents, on wide screens | | `footer` | Below everything | An empty slot renders nothing at all, not even a wrapper. Content injected before and after the page is kept out of the search index, so a banner or a prompt never shows up in results. ## Writing a slot component A slot component is a plain Astro component. It has access to everything ZenithDocs knows about the current page through `Astro.locals.zenith`: its title, URL, language, version, and the interface strings. ```astro title="src/components/Feedback.astro" --- const { title, editUrl } = Astro.locals.zenith; ---

Something wrong on “{title}”? {editUrl && Suggest a change}

``` :::note Slots live inside the built-in components. If you [override](/customization/overrides/) the `Header` or the `Sidebar`, the slots they contain go with them: render `InjectionPoint` from `zenith-docs/components/layout/InjectionPoint.astro` in your own component to keep them. :::