The Design object

The design object is the root of every Unlayer design. The embedded builder reads and writes it, the Cloud API exports, converts, and validates it, and every endpoint that takes a design accepts this shape.

Shape

{
  "counters": {
    "u_row": 4,
    "u_column": 6,
    "u_content_text": 3,
    "u_content_image": 2,
    "u_content_button": 1
  },
  "body": {
    "id": "body-1",
    "rows": [
      /* Row objects */
    ],
    "values": {
      /* body-level styling */
    }
  },
  "schemaVersion": 21
}

Fields

Field	Type	Required	Notes
body	Body	yes	The single body of the design — rows, columns, content, body-level styling. Email designs also accept body.headers and body.footers arrays.
counters	Record<string, number>	yes¹	Per-type counters the editor uses to assign stable IDs to new blocks (e.g. u_content_text: 3 means the next text block will be u_content_text_4). Required in the Full schema, optional in the Simple schema.
schemaVersion	number	no	The design-schema version the payload was authored against. Migrations apply forward when the editor loads a design from an older version.
_conversion	{ data: string, version: number}	no²	Present only on Simple-form designs that were produced with includeConversion: true on /v3/convert/full-to-simple. Pass it back to simple-to-full to round-trip cleanly.

¹ Required in the Full schema; optional in the Simple schema. ² Only present on Simple-form designs produced with includeConversion: true.

Email-only fields

body accepts two additional arrays in email designs:

Field	Type	Notes
body.headers	Row[]	Rows pinned to the top of every page when the email is broken across pages (PDF / printed scenarios).
body.footers	Row[]	Rows pinned to the bottom of every page.

Related

• Block object — what's inside body.rows.
• Content types — what each row's columns hold.
• Validate — verify a design conforms to the schema.