Seed File Format

Seed files are JSON documents that bootstrap EmDash sites. They define collections, fields, taxonomies, menus, redirects, widget areas, site settings, and optional sample content.

Root Structure

{
	"$schema": "https://emdashcms.com/seed.schema.json",
	"version": "1",
	"meta": {},
	"settings": {},
	"collections": [],
	"taxonomies": [],
	"bylines": [],
	"menus": [],
	"redirects": [],
	"widgetAreas": [],
	"sections": [],
	"content": {}
}

Meta

Optional metadata about the seed:

{
	"meta": {
		"name": "Blog Starter",
		"description": "A simple blog with posts, pages, and categories",
		"author": "EmDash"
	}
}

Settings

Site-wide configuration values:

{
	"settings": {
		"title": "My Site",
		"tagline": "A modern CMS",
		"postsPerPage": 10,
		"dateFormat": "MMMM d, yyyy"
	}
}

Settings are applied to the options table with the site: prefix. The Setup Wizard lets users override title and tagline.

Collections

Collection definitions create content types in the database:

{
	"collections": [
		{
			"slug": "posts",
			"label": "Posts",
			"labelSingular": "Post",
			"description": "Blog posts",
			"icon": "file-text",
			"supports": ["drafts", "revisions"],
			"fields": [
				{
					"slug": "title",
					"label": "Title",
					"type": "string",
					"required": true
				},
				{
					"slug": "content",
					"label": "Content",
					"type": "portableText"
				},
				{
					"slug": "featured_image",
					"label": "Featured Image",
					"type": "image"
				}
			]
		}
	]
}

Collection Properties

Field Properties

Field Types

Taxonomies

Classification systems for content:

{
	"taxonomies": [
		{
			"name": "category",
			"label": "Categories",
			"labelSingular": "Category",
			"hierarchical": true,
			"collections": ["posts"],
			"terms": [
				{ "slug": "news", "label": "News" },
				{ "slug": "tutorials", "label": "Tutorials" },
				{
					"slug": "advanced",
					"label": "Advanced Tutorials",
					"parent": "tutorials"
				}
			]
		},
		{
			"name": "tag",
			"label": "Tags",
			"labelSingular": "Tag",
			"hierarchical": false,
			"collections": ["posts"]
		}
	]
}

Taxonomy Properties

Term Properties

Menus

Navigation menus editable from the admin:

{
	"menus": [
		{
			"name": "primary",
			"label": "Primary Navigation",
			"items": [
				{ "type": "custom", "label": "Home", "url": "/" },
				{ "type": "page", "ref": "about" },
				{ "type": "custom", "label": "Blog", "url": "/posts" },
				{
					"type": "custom",
					"label": "External",
					"url": "https://example.com",
					"target": "_blank"
				}
			]
		}
	]
}

Menu Item Types

Menu Item Properties

Bylines

Byline profiles are separate from ownership (author_id). Define reusable byline identities once, then reference them from content entries.

{
	"bylines": [
		{
			"id": "editorial",
			"slug": "emdash-editorial",
			"displayName": "EmDash Editorial"
		},
		{
			"id": "guest",
			"slug": "guest-contributor",
			"displayName": "Guest Contributor",
			"isGuest": true
		}
	]
}

Redirects

Redirect rules to preserve legacy URLs after migration:

{
	"redirects": [
		{ "source": "/old-about", "destination": "/about" },
		{ "source": "/legacy-feed", "destination": "/rss.xml", "type": 308 },
		{
			"source": "/category/news",
			"destination": "/categories/news",
			"groupName": "migration"
		}
	]
}

Redirect Properties

Widget Areas

Configurable content regions:

{
	"widgetAreas": [
		{
			"name": "sidebar",
			"label": "Main Sidebar",
			"description": "Appears on blog posts and pages",
			"widgets": [
				{
					"type": "component",
					"title": "Recent Posts",
					"componentId": "core:recent-posts",
					"props": { "count": 5 }
				},
				{
					"type": "menu",
					"title": "Quick Links",
					"menuName": "footer"
				},
				{
					"type": "content",
					"title": "About",
					"content": [
						{
							"_type": "block",
							"style": "normal",
							"children": [{ "_type": "span", "text": "Welcome to our site!" }]
						}
					]
				}
			]
		}
	]
}

Widget Types

Built-in Components

Sections

Reusable content blocks that editors can insert into Portable Text fields via the /section slash command:

{
	"sections": [
		{
			"slug": "hero-centered",
			"title": "Centered Hero",
			"description": "Full-width hero with centered heading and CTA button",
			"keywords": ["hero", "banner", "header", "landing"],
			"content": [
				{
					"_type": "block",
					"style": "h1",
					"children": [{ "_type": "span", "text": "Welcome to Our Site" }]
				},
				{
					"_type": "block",
					"children": [
						{ "_type": "span", "text": "Your compelling tagline goes here." }
					]
				}
			]
		}
	]
}

Section Properties

Sections from seed files are marked source: "theme" and cannot be deleted from the admin UI. Editors can create their own sections (source: "user") and insert any section type when editing content.

Content

Sample content organized by collection:

{
	"content": {
		"posts": [
			{
				"id": "hello-world",
				"slug": "hello-world",
				"status": "published",
				"bylines": [
					{ "byline": "editorial" },
					{ "byline": "guest", "roleLabel": "Guest essay" }
				],
				"data": {
					"title": "Hello World",
					"content": [
						{
							"_type": "block",
							"style": "normal",
							"children": [{ "_type": "span", "text": "Welcome!" }]
						}
					],
					"excerpt": "Your first post."
				},
				"taxonomies": {
					"category": ["news"],
					"tag": ["welcome", "first-post"]
				}
			}
		],
		"pages": [
			{
				"id": "about",
				"slug": "about",
				"status": "published",
				"data": {
					"title": "About Us",
					"content": [
						{
							"_type": "block",
							"style": "normal",
							"children": [{ "_type": "span", "text": "About page content." }]
						}
					]
				}
			}
		]
	}
}

Content Entry Properties

Content References

Reference other content entries using the $ref: prefix:

{
	"data": {
		"related_posts": ["$ref:another-post", "$ref:third-post"]
	}
}

The $ref: prefix resolves seed IDs to database IDs during seeding.

Media References

Include images from URLs:

{
	"data": {
		"featured_image": {
			"$media": {
				"url": "https://images.unsplash.com/photo-xxx",
				"alt": "Description of the image",
				"filename": "hero.jpg",
				"caption": "Photo by Someone"
			}
		}
	}
}

Include local images from .emdash/media/:

{
	"data": {
		"featured_image": {
			"$media": {
				"file": "hero.jpg",
				"alt": "Description of the image"
			}
		}
	}
}

Media Properties

*Either url or file is required, not both.

Applying Seeds Programmatically

Use the seed API for CLI tools or scripts:

import { applySeed, validateSeed } from "emdash/seed";
import seedData from "./.emdash/seed.json";

// Validate first
const validation = validateSeed(seedData);
if (!validation.valid) {
	console.error(validation.errors);
	process.exit(1);
}

// Apply seed
const result = await applySeed(db, seedData, {
	includeContent: true,
	onConflict: "skip",
	storage: myStorage,
	baseUrl: "http://localhost:4321",
});

console.log(result);
// {
//   collections: { created: 2, skipped: 0 },
//   fields: { created: 8, skipped: 0 },
//   taxonomies: { created: 2, terms: 5 },
//   bylines: { created: 2, skipped: 0 },
//   menus: { created: 1, items: 4 },
//   redirects: { created: 3, skipped: 0 },
//   widgetAreas: { created: 1, widgets: 3 },
//   settings: { applied: 3 },
//   content: { created: 3, skipped: 0 },
//   media: { created: 2, skipped: 0 }
// }

Apply Options

Idempotency

Seeding is safe to run multiple times. Conflict behavior by entity type:

Validation

Seed files are validated before application:

import { validateSeed } from "emdash/seed";

const { valid, errors, warnings } = validateSeed(seedData);

if (!valid) {
	errors.forEach((e) => console.error(e));
}

warnings.forEach((w) => console.warn(w));

Validation checks:

• Required fields are present
• Slugs follow naming conventions (lowercase, underscores)
• Field types are valid
• References point to existing content
• Hierarchical term parents exist
• Redirect paths are safe local URLs
• Redirect sources are unique
• No duplicate slugs within collections

CLI Commands

# Apply seed file
npx emdash seed .emdash/seed.json

# Apply without sample content
npx emdash seed .emdash/seed.json --no-content

# Validate only
npx emdash seed .emdash/seed.json --validate

# Export current schema as seed
npx emdash export-seed > seed.json

# Export with content
npx emdash export-seed --with-content > seed.json

Next Steps

• Creating Themes — Build a complete theme
• Themes Overview — How themes work