Collections

A collection is a content type you define once and reuse for every entry of that type. It declares a label, a root, an optional set of child blocks, and optional slug behavior.

import { defineCollection } from '@createcms/core';

const posts = defineCollection({
  label: 'Posts',
  slug: { enabled: true, root: '/blog', nested: false },
  root: {
    properties: {
      title: { type: 'string', required: true, label: 'Title' },
      excerpt: { type: 'string', label: 'Excerpt' },
    },
  },
  blocks: {
    richText: {
      label: 'Rich text',
      properties: {
        content: { type: 'richText', required: true, label: 'Body' },
      },
    },
  },
});

Roots are entries

Each entry in a collection is a root. The root carries the collection's top-level properties (here, a post's title and excerpt) and anchors the tree of blocks beneath it. listRoots returns the entries of a collection, and createRoot adds one.

Slugs

The optional slug config gives entries a URL path. When enabled, you set the root prefix and choose how paths behave:

Slugs vs paths

A root's slug is a single segment (for example hello-world), not a full URL. The collection's root prefix and any ancestors are joined into the path:

slug:  hello-world
root:  /blog
path:  /blog/hello-world

listRoots returns both slug (the segment) and path (the resolved full URL). getPublishedContent always accepts a rootId; with slugs enabled, you can additionally look up by slug or path.

Reusable blocks and references

A reference property points one entry at another by rootId. On the published read, the referenced entry's content is inlined, so a page that embeds a shared block renders in one read.

Reuse vs duplicate: embed a reference when several entries should share content that is edited in one place (a change propagates to every embedder on the next read). Duplicate instead when each copy should diverge independently. Setting reusableBlock: true on a collection is only an editor hint that its roots are meant to be embedded; any collection can be a reference target.