Build and customize EmDash CMS sites on Astro. Use when creating pages, defining collections, writing seed files, querying content, rendering Portable Text, setting up menus/taxonomies/widgets, configuring deployment, or any task involving an EmDash-powered Astro site. Assumes basic Astro knowledge but provides all EmDash-specific patterns.
EmDash is a CMS built on Astro. It stores schema in the database (not in code), serves content via live content collections, and provides a full admin UI at /_emdash/admin. Sites are standard Astro projects with the emdash integration.
These are the things that silently break sites. Know them before you start.
Image fields are objects, not strings. post.data.featured_image is { id, src, alt }. Writing <img src={post.data.featured_image} /> renders [object Object]. Use <Image image={post.data.featured_image} /> from "emdash/ui".
entry.id vs entry.data.id are different things. entry.id is the slug (use in URLs). entry.data.id is the database ULID (use for getEntryTerms, Comments, and other API calls that need the real ID). Mixing them up causes silent empty results.
Taxonomy names must match the seed exactly. If your seed defines "name": "category", you must query getTerm("category", slug) -- not "categories". Wrong name = empty results, no error.
Always pass cacheHint to Astro.cache.set(). Every query returns a cacheHint. Call Astro.cache.set(cacheHint) on every page that queries content, or cache invalidation won't work when editors publish changes.
No getStaticPaths for CMS content. EmDash content is dynamic. Pages must be server-rendered (output: "server" in astro.config.mjs).
Every EmDash site has these key files:
my-site/
├── astro.config.mjs # Astro config with emdash() integration
├── src/
│ ├── live.config.ts # EmDash loader registration (boilerplate)
│ ├── pages/ # Astro pages (all server-rendered)
│ ├── layouts/ # Layout components
│ └── components/ # Reusable components
├── seed/
│ └── seed.json # Schema + demo content
├── emdash-env.d.ts # Generated types (from `emdash types`)
└── package.json
Read references/configuration.md for astro.config.mjs, live.config.ts, deployment targets (Node vs Cloudflare), and type generation.
Read references/schema-and-seed.md for collection definitions, field types, taxonomies, menus, widget areas, sections, bylines, and the complete seed file format.
Read references/querying-and-rendering.md for content queries, Portable Text rendering, the Image component, visual editing attributes, caching, and common page patterns (list, detail, taxonomy archive, RSS, search, 404).
Read references/site-features.md for site settings, navigation menus, taxonomies, widget areas, search, SEO meta, comments, and page contributions.
Write seed/seed.json with collections, fields, taxonomies, menus, widgets, and sample content. Validate with:
npx emdash seed seed/seed.json --validate
npx emdash dev # Start dev server (runs migrations + seeds, and generates types)
The admin UI is at http://localhost:4321/_emdash/admin.
// Content (entries have .data.byline and .data.bylines eagerly loaded)
import { getEmDashCollection, getEmDashEntry } from "emdash";
const { entries, nextCursor, cacheHint } = await getEmDashCollection("posts", {
limit: 10,
cursor,
orderBy: { published_at: "desc" },
});
const { entry: post, cacheHint } = await getEmDashEntry("posts", slug);
// Site features
import {
getSiteSettings,
getMenu,
getTaxonomyTerms,
getTerm,
getEntryTerms,
getEntriesByTerm,
getWidgetArea,
search,
getSection,
getSeoMeta,
} from "emdash";
// Bylines (standalone queries -- usually not needed since entries have bylines attached)
import { getEntryBylines, getBylinesForEntries, getByline, getBylineBySlug } from "emdash";
// UI components
import {
PortableText,
Image,
Comments,
CommentForm,
WidgetArea,
EmDashHead,
EmDashBodyStart,
EmDashBodyEnd,
} from "emdash/ui";
import LiveSearch from "emdash/ui/search";
// Page context (for plugin contributions)
import { createPublicPageContext } from "emdash/page";
EmDash supports plugins for extending the CMS with hooks, storage, settings, admin UI, API routes, and custom Portable Text block types. Consider a plugin when you need to:
Plugins are registered in astro.config.mjs:
emdash({
database: sqlite({ url: "file:./data.db" }),
storage: local({ directory: "./uploads", baseUrl: "/_emdash/api/media/file" }),
plugins: [myPlugin()],
}),
To build a plugin, load the creating-plugins skill (in .agents/skills/creating-plugins/). It covers plugin anatomy, hooks, storage, admin UI, API routes, Portable Text blocks, capabilities, and the full definePlugin() API.
| File | Contents |
|---|---|
| references/configuration.md | Project setup, astro.config, live.config, deployment, types |
| references/schema-and-seed.md | Collections, fields, taxonomies, menus, widgets, seed format |
| references/querying-and-rendering.md | Content APIs, PortableText, Image, caching, page patterns |
| references/site-features.md | Settings, menus, widgets, search, SEO, comments, page contributions |