# Templates

Source: https://kirora.io/docs/api/reference/templates

A template is a reusable email design: a document of blocks and a theme, saved as a draft and published as numbered versions. Campaigns copy a template when they are built, so editing a template never changes a campaign already made from it. Send only from a published version; an agent key's edits wait for a person to publish them. See [Templates as code](https://kirora.io/docs/api/templates-as-code).

## Endpoints

- [List templates](https://kirora.io/docs/api/reference/listTemplates): `GET /v1/templates`
- [Create an email template](https://kirora.io/docs/api/reference/createTemplate): `POST /v1/templates`
- [Retrieve a template](https://kirora.io/docs/api/reference/getTemplate): `GET /v1/templates/{id}`
- [Update a template](https://kirora.io/docs/api/reference/updateTemplate): `PATCH /v1/templates/{id}`
- [Delete a template](https://kirora.io/docs/api/reference/deleteTemplate): `DELETE /v1/templates/{id}`
- [List sample emails and theme presets](https://kirora.io/docs/api/reference/getTemplateGallery): `GET /v1/templates/gallery`
- [Render a saved template](https://kirora.io/docs/api/reference/renderTemplate): `POST /v1/templates/{id}/render`
- [Render a design or HTML](https://kirora.io/docs/api/reference/renderTemplateContent): `POST /v1/templates/render`
- [Send a test email](https://kirora.io/docs/api/reference/sendTemplateTest): `POST /v1/templates/test-send`
- [Publish a template](https://kirora.io/docs/api/reference/publishTemplate): `POST /v1/templates/{id}/publish`
- [List a template's versions](https://kirora.io/docs/api/reference/listTemplateVersions): `GET /v1/templates/{id}/versions`
- [Retrieve a template version](https://kirora.io/docs/api/reference/getTemplateVersion): `GET /v1/templates/{id}/versions/{version}`
- [Restore a template version](https://kirora.io/docs/api/reference/restoreTemplateVersion): `POST /v1/templates/{id}/versions/{version}/restore`
- [Duplicate a template](https://kirora.io/docs/api/reference/duplicateTemplate): `POST /v1/templates/{id}/duplicate`
- [Retrieve the workspace brand kit](https://kirora.io/docs/api/reference/getBrandKit): `GET /v1/brand-kit`

## The Template object

```json
{
  "id": "0192f3d0-1a2b-7c3d-8e4f-5a6b7c8d9e0f",
  "name": "Welcome email",
  "kind": "design",
  "schemaVersion": 1,
  "blocks": [
    {
      "id": "title",
      "type": "heading",
      "text": "Welcome to Acme Shop",
      "size": "28px"
    },
    {
      "id": "intro",
      "type": "text",
      "text": "Hi {{ contact.firstName }}, thanks for joining. Your first order ships free."
    },
    {
      "id": "shop",
      "type": "button",
      "text": "Start shopping",
      "href": "https://acme-shop.com"
    },
    {
      "id": "store-footer",
      "type": "shared",
      "sharedBlockId": "0192f3d1-3c4d-7e5f-8a61-7c8d9e0f1a2b"
    },
    {
      "id": "footer",
      "type": "footer",
      "text": "{{ org.name }}\n{{ org.address }}",
      "locked": true
    }
  ],
  "theme": {
    "bodyFontFamily": "Arial, sans-serif",
    "headingFontFamily": "Georgia, serif",
    "cardBackgroundColor": "#ffffff",
    "canvasBackgroundColor": "#f4f1ec",
    "textColor": "#1f2933",
    "accentColor": "#b4461f",
    "linkColor": "#b4461f",
    "cardWidth": "600px",
    "cardBorderRadius": "6px",
    "buttonStyle": "solid"
  },
  "language": "en",
  "plainTextOverride": null,
  "transactionalDefaults": {
    "subject": "Welcome to Acme Shop",
    "previewText": "Your first order ships free",
    "from": "Acme Shop <hello@mail.acme-shop.com>",
    "replyTo": "support@acme-shop.com"
  },
  "alias": "welcome",
  "publishedVersion": 1,
  "hasUnpublishedChanges": false,
  "revision": 2,
  "thumbnailUrl": "https://assets.kirora.io/thumbnails/0192f3d0-1a2b-7c3d-8e4f-5a6b7c8d9e0f.png",
  "tags": [
    "Onboarding"
  ],
  "createdAt": "2026-10-01T09:30:00.000Z",
  "updatedAt": "2026-10-02T14:05:00.000Z"
}
```

- One of: **DesignTemplate**
  - `id` (string, required, uuid)
  - `name` (string, required)
  - `plainTextOverride` (string | null, required) — Plain text sent instead of the version generated from the design or HTML.
  - `transactionalDefaults` (TransactionalDefaults, required) — What a transactional send of the template uses unless the send gives its own; `null` leaves it to the send. Campaigns and journeys set their own.
    - `subject` (string | null, required) — The subject line; may hold merge tags.
    - `previewText` (string | null, required) — The inbox preview text after the subject; may hold merge tags.
    - `from` (string | null, required) — The sender: one address, optionally with a display name.
    - `replyTo` (string | null, required, email) — The address replies go to.
  - `alias` (string | null, required) — The name a transactional send may use in `email.template`.
  - `publishedVersion` (integer | null, required, min > 0) — The version API sends use; null until published. The template itself is the draft.
  - `hasUnpublishedChanges` (boolean, required) — The draft differs from the published version, the brand or a shared block it places has changed since it was published, or it was never published.
  - `revision` (integer, required, min > 0, max 2147483647) — Raised by every edit. Send it back as `expectedRevision` on the update so a change made since you read it is refused instead of overwritten.
  - `thumbnailUrl` (string | null, required, uri) — A small picture of the design (WebP, 640 × 853, shown at half size), redrawn a few seconds after each save, at a new address each time; null until the first is drawn.
  - `tags` (string[], required) — Tag names, sorted without case.
  - `createdAt` (string, required, date-time)
  - `updatedAt` (string, required, date-time)
  - `kind` ("design", required) — Built from blocks in the designer.
  - `schemaVersion` (integer, required, min > 0, max 1000) — The block format version.
  - `blocks` (object[], required, at least 1 item, at most 200 items) — The blocks, rendered top to bottom: at most 200 across the whole tree and five levels including the root. The footer stays at the root.
    - One of: **HeaderBlock**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("header", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `visibleIf` ([object](https://kirora.io/docs/api/models#segment-rules), optional) — Show the block only to contacts these segment rules match, checked as each message is rendered. Omit to show it to everyone.
        - Any of: **Match all**
        - Any of: **Match any**
      - `visibleIfPresent` (string, optional, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — Show the block only when this value is present (not missing, empty or false), such as `data.vat` for a VAT row; checked as each message is rendered.
      - `showOn` (string, optional, one of `mobile`, `desktop`) — Show the block only on phones (screens up to 620px) or only on wider screens. Clients that ignore screen size show the desktop version, and so does plain text. Omit to show it everywhere.
      - `src` (string, optional, up to 2,048 characters) — The logo image's URL; without one, the brand kit's logo.
      - `alt` (string, optional, up to 100,000 characters) — The logo's alt text. Without `src` or a brand kit logo, it shows as a wordmark in the heading font; gallery samples set it to `{{ org.name }}`.
      - `width` (string, optional) — A share of the row ("100%", "66%", "50%"), or a fixed width from "16px" to "600px", such as "120px" for a logo. Never wider than the row.
      - `align` (string, optional, one of `left`, `center`, `right`) — When unset, headings, text, buttons and boxed text start from the reading side (left, or right in a right-to-left language); other blocks centre.
      - `href` (string, optional, up to 2,048 characters) — Where it links: an `https:`, `http:`, `mailto:` or `tel:` address, or a merge tag. `https://` is added to a bare address such as `acme.com/setup`. A draft may hold anything; a button or video whose link is none of these cannot be published or sent.
    - One of: **HeadingBlock**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("heading", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `visibleIf` ([object](https://kirora.io/docs/api/models#segment-rules), optional) — Show the block only to contacts these segment rules match, checked as each message is rendered. Omit to show it to everyone.
        - Any of: **Match all**
        - Any of: **Match any**
      - `visibleIfPresent` (string, optional, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — Show the block only when this value is present (not missing, empty or false), such as `data.vat` for a VAT row; checked as each message is rendered.
      - `showOn` (string, optional, one of `mobile`, `desktop`) — Show the block only on phones (screens up to 620px) or only on wider screens. Clients that ignore screen size show the desktop version, and so does plain text. Omit to show it everywhere.
      - `text` (string, optional, up to 100,000 characters)
      - `size` (string, optional, one of `28px`, `22px`, `18px`)
      - `align` (string, optional, one of `left`, `center`, `right`) — When unset, headings, text, buttons and boxed text start from the reading side (left, or right in a right-to-left language); other blocks centre.
      - `weight` (string, optional, one of `regular`, `bold`)
    - One of: **TextBlock**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("text", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `visibleIf` ([object](https://kirora.io/docs/api/models#segment-rules), optional) — Show the block only to contacts these segment rules match, checked as each message is rendered. Omit to show it to everyone.
        - Any of: **Match all**
        - Any of: **Match any**
      - `visibleIfPresent` (string, optional, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — Show the block only when this value is present (not missing, empty or false), such as `data.vat` for a VAT row; checked as each message is rendered.
      - `showOn` (string, optional, one of `mobile`, `desktop`) — Show the block only on phones (screens up to 620px) or only on wider screens. Clients that ignore screen size show the desktop version, and so does plain text. Omit to show it everywhere.
      - `text` (string, optional, up to 100,000 characters)
      - `align` (string, optional, one of `left`, `center`, `right`) — When unset, headings, text, buttons and boxed text start from the reading side (left, or right in a right-to-left language); other blocks centre.
    - One of: **ImageBlock**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("image", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `visibleIf` ([object](https://kirora.io/docs/api/models#segment-rules), optional) — Show the block only to contacts these segment rules match, checked as each message is rendered. Omit to show it to everyone.
        - Any of: **Match all**
        - Any of: **Match any**
      - `visibleIfPresent` (string, optional, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — Show the block only when this value is present (not missing, empty or false), such as `data.vat` for a VAT row; checked as each message is rendered.
      - `showOn` (string, optional, one of `mobile`, `desktop`) — Show the block only on phones (screens up to 620px) or only on wider screens. Clients that ignore screen size show the desktop version, and so does plain text. Omit to show it everywhere.
      - `src` (string, optional, up to 2,048 characters)
      - `alt` (string, optional, up to 100,000 characters)
      - `width` (string, optional) — A share of the row ("100%", "66%", "50%"), or a fixed width from "16px" to "600px", such as "120px" for a logo. Never wider than the row.
      - `align` (string, optional, one of `left`, `center`, `right`) — When unset, headings, text, buttons and boxed text start from the reading side (left, or right in a right-to-left language); other blocks centre.
      - `href` (string, optional, up to 2,048 characters) — Where it links: an `https:`, `http:`, `mailto:` or `tel:` address, or a merge tag. `https://` is added to a bare address such as `acme.com/setup`. A draft may hold anything; a button or video whose link is none of these cannot be published or sent.
    - One of: **ButtonBlock**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("button", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `visibleIf` ([object](https://kirora.io/docs/api/models#segment-rules), optional) — Show the block only to contacts these segment rules match, checked as each message is rendered. Omit to show it to everyone.
        - Any of: **Match all**
        - Any of: **Match any**
      - `visibleIfPresent` (string, optional, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — Show the block only when this value is present (not missing, empty or false), such as `data.vat` for a VAT row; checked as each message is rendered.
      - `showOn` (string, optional, one of `mobile`, `desktop`) — Show the block only on phones (screens up to 620px) or only on wider screens. Clients that ignore screen size show the desktop version, and so does plain text. Omit to show it everywhere.
      - `text` (string, optional, up to 100,000 characters)
      - `href` (string, optional, up to 2,048 characters) — Where it links: an `https:`, `http:`, `mailto:` or `tel:` address, or a merge tag. `https://` is added to a bare address such as `acme.com/setup`. A draft may hold anything; a button or video whose link is none of these cannot be published or sent.
      - `align` (string, optional, one of `left`, `center`, `right`) — When unset, headings, text, buttons and boxed text start from the reading side (left, or right in a right-to-left language); other blocks centre.
      - `fullWidth` (boolean, optional)
      - `color` (string, optional) — A hex colour, or a theme reference: `accent`, `canvas`, or `accent-tint` / `canvas-tint` (a light tint of it), which follows the theme.
      - `buttonStyle` (string, optional, one of `solid`, `outline`) — This button's style, in place of the theme's.
    - One of: **DividerBlock**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("divider", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `visibleIf` ([object](https://kirora.io/docs/api/models#segment-rules), optional) — Show the block only to contacts these segment rules match, checked as each message is rendered. Omit to show it to everyone.
        - Any of: **Match all**
        - Any of: **Match any**
      - `visibleIfPresent` (string, optional, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — Show the block only when this value is present (not missing, empty or false), such as `data.vat` for a VAT row; checked as each message is rendered.
      - `showOn` (string, optional, one of `mobile`, `desktop`) — Show the block only on phones (screens up to 620px) or only on wider screens. Clients that ignore screen size show the desktop version, and so does plain text. Omit to show it everywhere.
      - `thickness` (integer, optional, min 1, max 10) — Line weight in px.
      - `color` (string, optional) — A hex colour, or a theme reference: `accent`, `canvas`, or `accent-tint` / `canvas-tint` (a light tint of it), which follows the theme.
      - `lineStyle` (string, optional, one of `solid`, `dashed`, `dotted`)
      - `width` (string, optional, one of `100%`, `75%`, `50%`, `25%`) — How much of the row the line spans.
      - `align` (string, optional, one of `left`, `center`, `right`) — When unset, headings, text, buttons and boxed text start from the reading side (left, or right in a right-to-left language); other blocks centre.
    - One of: **SpacerBlock**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("spacer", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `visibleIf` ([object](https://kirora.io/docs/api/models#segment-rules), optional) — Show the block only to contacts these segment rules match, checked as each message is rendered. Omit to show it to everyone.
        - Any of: **Match all**
        - Any of: **Match any**
      - `visibleIfPresent` (string, optional, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — Show the block only when this value is present (not missing, empty or false), such as `data.vat` for a VAT row; checked as each message is rendered.
      - `showOn` (string, optional, one of `mobile`, `desktop`) — Show the block only on phones (screens up to 620px) or only on wider screens. Clients that ignore screen size show the desktop version, and so does plain text. Omit to show it everywhere.
      - `size` (string, optional, pattern `^\d{1,3}px$`) — The height, from "4px" to "200px".
    - One of: **ColumnsBlock**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("columns", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `visibleIf` ([object](https://kirora.io/docs/api/models#segment-rules), optional) — Show the block only to contacts these segment rules match, checked as each message is rendered. Omit to show it to everyone.
        - Any of: **Match all**
        - Any of: **Match any**
      - `visibleIfPresent` (string, optional, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — Show the block only when this value is present (not missing, empty or false), such as `data.vat` for a VAT row; checked as each message is rendered.
      - `showOn` (string, optional, one of `mobile`, `desktop`) — Show the block only on phones (screens up to 620px) or only on wider screens. Clients that ignore screen size show the desktop version, and so does plain text. Omit to show it everywhere.
      - `widths` (integer[], optional, at least 2 items, at most 2 items) — Each column's share of the row in percent, left to right, one per column and adding up to 100, such as [33, 67]. Omit for equal columns.
      - `valign` (string, optional, one of `top`, `middle`, `bottom`) — Where shorter columns sit against the tallest one.
      - `stackOnMobile` (boolean, optional) — False keeps the columns side by side on phones too, such as a two-across product grid; by default they stack.
      - `columns` (object[][], required, at least 2 items, at most 2 items) — The child blocks of each column, left to right: exactly 2 arrays.
    - One of: **Columns3Block**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("columns3", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `visibleIf` ([object](https://kirora.io/docs/api/models#segment-rules), optional) — Show the block only to contacts these segment rules match, checked as each message is rendered. Omit to show it to everyone.
        - Any of: **Match all**
        - Any of: **Match any**
      - `visibleIfPresent` (string, optional, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — Show the block only when this value is present (not missing, empty or false), such as `data.vat` for a VAT row; checked as each message is rendered.
      - `showOn` (string, optional, one of `mobile`, `desktop`) — Show the block only on phones (screens up to 620px) or only on wider screens. Clients that ignore screen size show the desktop version, and so does plain text. Omit to show it everywhere.
      - `widths` (integer[], optional, at least 3 items, at most 3 items) — Each column's share of the row in percent, left to right, one per column and adding up to 100, such as [33, 67]. Omit for equal columns.
      - `valign` (string, optional, one of `top`, `middle`, `bottom`) — Where shorter columns sit against the tallest one.
      - `stackOnMobile` (boolean, optional) — False keeps the columns side by side on phones too, such as a two-across product grid; by default they stack.
      - `columns` (object[][], required, at least 3 items, at most 3 items) — The child blocks of each column, left to right: exactly 3 arrays.
    - One of: **ImageTextBlock**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("imagetext", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `visibleIf` ([object](https://kirora.io/docs/api/models#segment-rules), optional) — Show the block only to contacts these segment rules match, checked as each message is rendered. Omit to show it to everyone.
        - Any of: **Match all**
        - Any of: **Match any**
      - `visibleIfPresent` (string, optional, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — Show the block only when this value is present (not missing, empty or false), such as `data.vat` for a VAT row; checked as each message is rendered.
      - `showOn` (string, optional, one of `mobile`, `desktop`) — Show the block only on phones (screens up to 620px) or only on wider screens. Clients that ignore screen size show the desktop version, and so does plain text. Omit to show it everywhere.
      - `src` (string, optional, up to 2,048 characters)
      - `alt` (string, optional, up to 100,000 characters)
      - `text` (string, optional, up to 100,000 characters)
      - `side` (string, optional, one of `left`, `right`) — Which side the image sits on; unset, the start of the reading direction (left, or right in a right-to-left language).
    - One of: **ImageGroupBlock**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("imagegroup", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `visibleIf` ([object](https://kirora.io/docs/api/models#segment-rules), optional) — Show the block only to contacts these segment rules match, checked as each message is rendered. Omit to show it to everyone.
        - Any of: **Match all**
        - Any of: **Match any**
      - `visibleIfPresent` (string, optional, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — Show the block only when this value is present (not missing, empty or false), such as `data.vat` for a VAT row; checked as each message is rendered.
      - `showOn` (string, optional, one of `mobile`, `desktop`) — Show the block only on phones (screens up to 620px) or only on wider screens. Clients that ignore screen size show the desktop version, and so does plain text. Omit to show it everywhere.
      - `count` (2 | 3, optional)
      - `images` (object[], optional, at most 3 items)
        - `src` (string, optional, up to 2,048 characters)
        - `alt` (string, optional, up to 100,000 characters)
    - One of: **BoxedBlock**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("boxed", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `visibleIf` ([object](https://kirora.io/docs/api/models#segment-rules), optional) — Show the block only to contacts these segment rules match, checked as each message is rendered. Omit to show it to everyone.
        - Any of: **Match all**
        - Any of: **Match any**
      - `visibleIfPresent` (string, optional, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — Show the block only when this value is present (not missing, empty or false), such as `data.vat` for a VAT row; checked as each message is rendered.
      - `showOn` (string, optional, one of `mobile`, `desktop`) — Show the block only on phones (screens up to 620px) or only on wider screens. Clients that ignore screen size show the desktop version, and so does plain text. Omit to show it everywhere.
      - `text` (string, optional, up to 100,000 characters)
      - `align` (string, optional, one of `left`, `center`, `right`) — When unset, headings, text, buttons and boxed text start from the reading side (left, or right in a right-to-left language); other blocks centre.
    - One of: **QuoteBlock**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("quote", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `visibleIf` ([object](https://kirora.io/docs/api/models#segment-rules), optional) — Show the block only to contacts these segment rules match, checked as each message is rendered. Omit to show it to everyone.
        - Any of: **Match all**
        - Any of: **Match any**
      - `visibleIfPresent` (string, optional, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — Show the block only when this value is present (not missing, empty or false), such as `data.vat` for a VAT row; checked as each message is rendered.
      - `showOn` (string, optional, one of `mobile`, `desktop`) — Show the block only on phones (screens up to 620px) or only on wider screens. Clients that ignore screen size show the desktop version, and so does plain text. Omit to show it everywhere.
      - `text` (string, optional, up to 100,000 characters)
      - `text2` (string, optional, up to 100,000 characters)
    - One of: **ListBlock**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("list", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `visibleIf` ([object](https://kirora.io/docs/api/models#segment-rules), optional) — Show the block only to contacts these segment rules match, checked as each message is rendered. Omit to show it to everyone.
        - Any of: **Match all**
        - Any of: **Match any**
      - `visibleIfPresent` (string, optional, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — Show the block only when this value is present (not missing, empty or false), such as `data.vat` for a VAT row; checked as each message is rendered.
      - `showOn` (string, optional, one of `mobile`, `desktop`) — Show the block only on phones (screens up to 620px) or only on wider screens. Clients that ignore screen size show the desktop version, and so does plain text. Omit to show it everywhere.
      - `text` (string, optional, up to 100,000 characters)
    - One of: **ProductBlock**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("product", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `visibleIf` ([object](https://kirora.io/docs/api/models#segment-rules), optional) — Show the block only to contacts these segment rules match, checked as each message is rendered. Omit to show it to everyone.
        - Any of: **Match all**
        - Any of: **Match any**
      - `visibleIfPresent` (string, optional, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — Show the block only when this value is present (not missing, empty or false), such as `data.vat` for a VAT row; checked as each message is rendered.
      - `showOn` (string, optional, one of `mobile`, `desktop`) — Show the block only on phones (screens up to 620px) or only on wider screens. Clients that ignore screen size show the desktop version, and so does plain text. Omit to show it everywhere.
      - `weight` (string, optional, one of `regular`, `bold`) — The name and price in bold (the default) or regular weight.
      - `text` (string, optional, up to 100,000 characters)
      - `text2` (string, optional, up to 100,000 characters)
      - `desc` (string, optional, up to 100,000 characters)
      - `href` (string, optional, up to 2,048 characters) — Where it links: an `https:`, `http:`, `mailto:` or `tel:` address, or a merge tag. `https://` is added to a bare address such as `acme.com/setup`. A draft may hold anything; a button or video whose link is none of these cannot be published or sent.
      - `src` (string, optional, up to 2,048 characters)
      - `alt` (string, optional, up to 100,000 characters)
    - One of: **VideoBlock**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("video", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `visibleIf` ([object](https://kirora.io/docs/api/models#segment-rules), optional) — Show the block only to contacts these segment rules match, checked as each message is rendered. Omit to show it to everyone.
        - Any of: **Match all**
        - Any of: **Match any**
      - `visibleIfPresent` (string, optional, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — Show the block only when this value is present (not missing, empty or false), such as `data.vat` for a VAT row; checked as each message is rendered.
      - `showOn` (string, optional, one of `mobile`, `desktop`) — Show the block only on phones (screens up to 620px) or only on wider screens. Clients that ignore screen size show the desktop version, and so does plain text. Omit to show it everywhere.
      - `src` (string, optional, up to 2,048 characters)
      - `alt` (string, optional, up to 100,000 characters)
      - `text` (string, optional, up to 100,000 characters)
      - `href` (string, optional, up to 2,048 characters) — Where it links: an `https:`, `http:`, `mailto:` or `tel:` address, or a merge tag. `https://` is added to a bare address such as `acme.com/setup`. A draft may hold anything; a button or video whose link is none of these cannot be published or sent.
    - One of: **SocialBlock**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("social", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `visibleIf` ([object](https://kirora.io/docs/api/models#segment-rules), optional) — Show the block only to contacts these segment rules match, checked as each message is rendered. Omit to show it to everyone.
        - Any of: **Match all**
        - Any of: **Match any**
      - `visibleIfPresent` (string, optional, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — Show the block only when this value is present (not missing, empty or false), such as `data.vat` for a VAT row; checked as each message is rendered.
      - `showOn` (string, optional, one of `mobile`, `desktop`) — Show the block only on phones (screens up to 620px) or only on wider screens. Clients that ignore screen size show the desktop version, and so does plain text. Omit to show it everywhere.
      - `align` (string, optional, one of `left`, `center`, `right`) — When unset, headings, text, buttons and boxed text start from the reading side (left, or right in a right-to-left language); other blocks centre.
      - `links` (object[], optional, at most 10 items) — The profiles to show; without any, the brand kit's social links.
        - `label` (string, required, 1–80 characters)
        - `href` (string, required, uri, pattern `^[^\s{}]*$`, up to 2,048 characters)
      - `display` (string, optional, one of `icons`, `both`, `text`) — Each link as its network's icon (the default), the icon and its label, or the label alone. The network is read from the link's address; any other address shows a globe.
      - `iconStyle` (string, optional, one of `color`, `dark`, `light`) — Icons in each network's colour (the default), near-black, or white for a dark background.
    - One of: **MenuBlock**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("menu", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `visibleIf` ([object](https://kirora.io/docs/api/models#segment-rules), optional) — Show the block only to contacts these segment rules match, checked as each message is rendered. Omit to show it to everyone.
        - Any of: **Match all**
        - Any of: **Match any**
      - `visibleIfPresent` (string, optional, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — Show the block only when this value is present (not missing, empty or false), such as `data.vat` for a VAT row; checked as each message is rendered.
      - `showOn` (string, optional, one of `mobile`, `desktop`) — Show the block only on phones (screens up to 620px) or only on wider screens. Clients that ignore screen size show the desktop version, and so does plain text. Omit to show it everywhere.
      - `links` (object[], optional, at most 8 items) — The entries, left to right: at most 8 { label, href }.
        - `label` (string, required, 1–80 characters)
        - `href` (string, required, uri, pattern `^[^\s{}]*$`, up to 2,048 characters)
      - `align` (string, optional, one of `left`, `center`, `right`) — When unset, headings, text, buttons and boxed text start from the reading side (left, or right in a right-to-left language); other blocks centre.
      - `separator` (string, optional, one of `none`, `bar`, `dot`) — What stands between entries: space only, a bar or a dot.
    - One of: **HtmlBlock**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("html", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `visibleIf` ([object](https://kirora.io/docs/api/models#segment-rules), optional) — Show the block only to contacts these segment rules match, checked as each message is rendered. Omit to show it to everyone.
        - Any of: **Match all**
        - Any of: **Match any**
      - `visibleIfPresent` (string, optional, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — Show the block only when this value is present (not missing, empty or false), such as `data.vat` for a VAT row; checked as each message is rendered.
      - `showOn` (string, optional, one of `mobile`, `desktop`) — Show the block only on phones (screens up to 620px) or only on wider screens. Clients that ignore screen size show the desktop version, and so does plain text. Omit to show it everywhere.
      - `text` (string, optional, up to 100,000 characters)
    - One of: **SectionBlock**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("section", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `visibleIf` ([object](https://kirora.io/docs/api/models#segment-rules), optional) — Show the block only to contacts these segment rules match, checked as each message is rendered. Omit to show it to everyone.
        - Any of: **Match all**
        - Any of: **Match any**
      - `visibleIfPresent` (string, optional, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — Show the block only when this value is present (not missing, empty or false), such as `data.vat` for a VAT row; checked as each message is rendered.
      - `showOn` (string, optional, one of `mobile`, `desktop`) — Show the block only on phones (screens up to 620px) or only on wider screens. Clients that ignore screen size show the desktop version, and so does plain text. Omit to show it everywhere.
      - `backgroundImage` (string, optional, pattern `^https:\/\/[^\s"'()<>\\{}]+$`, up to 2,048 characters) — A photo behind the section's blocks, covering the box. Needs `style.backgroundColor`, which Outlook for Windows and clients with images off show instead, and which text is made readable on.
      - `blocks` (object[], required, at least 1 item, at most 200 items) — The section's child blocks, drawn inside its box.
    - One of: **FooterBlock**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("footer", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `text` (string, optional, up to 100,000 characters)
      - `locked` (true, optional)
      - `align` (string, optional, one of `left`, `center`, `right`) — When unset, headings, text, buttons and boxed text start from the reading side (left, or right in a right-to-left language); other blocks centre.
      - `unsubscribeLink` (boolean, optional) — False leaves out the unsubscribe link, for a transactional email (a receipt, a sign-in code). A marketing send adds the sender's own link anyway.
      - `unsubscribeLabel` (string, optional, up to 80 characters) — The words of the unsubscribe link, "Unsubscribe" by default. The link opens a page that also manages topic preferences, so "Unsubscribe or manage preferences" is accurate.
    - One of: **RepeatBlock**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("repeat", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `visibleIf` ([object](https://kirora.io/docs/api/models#segment-rules), optional) — Show the block only to contacts these segment rules match, checked as each message is rendered. Omit to show it to everyone.
        - Any of: **Match all**
        - Any of: **Match any**
      - `visibleIfPresent` (string, optional, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — Show the block only when this value is present (not missing, empty or false), such as `data.vat` for a VAT row; checked as each message is rendered.
      - `showOn` (string, optional, one of `mobile`, `desktop`) — Show the block only on phones (screens up to 620px) or only on wider screens. Clients that ignore screen size show the desktop version, and so does plain text. Omit to show it everywhere.
      - `list` (string, required, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — The list to repeat over: `event.properties.<name>` (a journey's event, or a transactional send's `data`) or `contact.attributes.<name>`.
      - `limit` (integer, optional, min 1, max 100)
      - `blocks` (object[], required, at least 1 item, at most 200 items) — The blocks written out once per item of `list`, where `{{ item.<field> }}` reads that item. Repeats do not nest.
    - One of: **SharedBlockReference**
      - `id` (string, required, 1–128 characters) — Identifies the block within the template; unique among its blocks.
      - `type` ("shared", required)
      - `style` (EmailBlockStyle, optional) — Visual overrides for this block, such as colours, font and spacing.
        - `backgroundColor` (string, optional) — Fill behind the block.
        - `fontFamily` (string, optional, one of `arial`, `verdana`, `georgia`, `tahoma`, `times-new-roman`, `courier-new`, `inter`, `roboto`, `open-sans`, `lato`, `montserrat`, `poppins`, `dm-sans`, `nunito`, `work-sans`, `oswald`, `ubuntu`, `mulish`, `manrope`, `quicksand`, `rubik`, `josefin-sans`, `epilogue`, `noto-sans`, `space-grotesk`, `plus-jakarta-sans`, `outfit`, `bricolage-grotesque`, `sora`, `ibm-plex-sans`, `geist`, `space-mono`, `playfair-display`, `merriweather`, `lora`, `libre-baskerville`, `eb-garamond`, `fraunces`, `source-serif-4`, `cormorant-garamond`) — A font id: one every client has (arial, verdana, georgia, tahoma, times-new-roman, courier-new), or a web font, which shows where the client loads it and falls back to a safe font elsewhere. Form themes use the same ids.
        - `fontSize` (integer, optional, min 12, max 72) — Text size in px, 12 to 72.
        - `mobileFontSize` (integer, optional, min 12, max 72) — Text size in px on phones (screens up to 620px), 12 to 72. Email apps that ignore mobile styles use `fontSize`.
        - `padding` (object, optional) — Space inside the block in px, 0 to 100 per side; omitted sides keep their default.
        - `mobilePadding` (object, optional) — Space inside the block in px on phones (screens up to 620px), 0 to 100 per side; omitted sides keep the block's `padding` (or its default). Email apps that ignore mobile styles use `padding`.
        - `borderWidth` (integer, optional, min 0, max 10) — Border thickness in px; 0 for none.
        - `borderStyle` (string, optional, one of `solid`, `dashed`, `dotted`) — Border line style.
        - `borderColor` (string, optional) — Border colour.
        - `borderRadius` (integer, optional, min 0, max 100) — Corner rounding in px, 0 to 100.
        - `textColor` (string, optional) — Text colour.
        - `linkColor` (string, optional) — Colour of links in the text.
        - `linkUnderline` (boolean, optional) — Set to false for links without an underline, such as a row of rating numbers or stars.
        - `letterSpacing` (number, optional, min -2, max 20) — Space between letters in px, such as 3 for a spaced-out eyebrow line.
        - `textTransform` (string, optional, one of `none`, `uppercase`) — Set to `uppercase` to capitalise all text.
        - `lineHeight` (number, optional, min 1, max 3) — A multiple of the font size.
        - `fontWeight` (string, optional, one of `regular`, `bold`) — Text weight.
        - `fontStyle` (string, optional, one of `normal`, `italic`) — Text style.
        - `inset` (boolean, optional) — Draw the background and border as a box within the content width, not across the whole row.
      - `visibleIfPresent` (string, optional, pattern `^(?:contact\.attributes\.[\p{L}\p{N}\p{M}_.-]{1,64}|(?:event\.properties|data)\.[A-Za-z0-9_.-]+)$`) — Show the block only when this value is present (not missing, empty or false), such as `data.vat` for a VAT row; checked as each message is rendered.
      - `showOn` (string, optional, one of `mobile`, `desktop`) — Show the block only on phones (screens up to 620px) or only on wider screens. Clients that ignore screen size show the desktop version, and so does plain text. Omit to show it everywhere.
      - `sharedBlockId` (string, required, uuid) — The workspace's shared block placed here, by reference.
      - `override` (object[], optional, at least 1 item, at most 200 items) — Edited here only: these blocks render instead of the shared content. Omit to follow the shared block.
  - `theme` (EmailTheme, required) — Theme values this email overrides.
    - `bodyFontFamily` (string, optional, pattern `^[\w\s,'"-]+$`, up to 200 characters) — Body font stack, such as `Inter, sans-serif`.
    - `headingFontFamily` (string, optional, pattern `^[\w\s,'"-]+$`, up to 200 characters) — Heading font stack.
    - `cardBackgroundColor` (string, optional, pattern `^#(?:[0-9a-f]{3}|[0-9a-f]{6})$`) — Background of the email card, as hex.
    - `canvasBackgroundColor` (string, optional, pattern `^#(?:[0-9a-f]{3}|[0-9a-f]{6})$`) — Background behind the card, as hex.
    - `textColor` (string, optional, pattern `^#(?:[0-9a-f]{3}|[0-9a-f]{6})$`) — Default text colour, as hex.
    - `accentColor` (string, optional, pattern `^#(?:[0-9a-f]{3}|[0-9a-f]{6})$`) — Brand colour for buttons and highlights, as hex.
    - `linkColor` (string, optional, pattern `^#(?:[0-9a-f]{3}|[0-9a-f]{6})$`) — Link colour, as hex.
    - `headingColor` (string, optional, pattern `^#(?:[0-9a-f]{3}|[0-9a-f]{6})$`) — Heading colour, as hex; unset, headings take `textColor`.
    - `buttonTextColor` (string, optional, pattern `^#(?:[0-9a-f]{3}|[0-9a-f]{6})$`) — Label colour of solid buttons in `accentColor`, as hex; unset, white or near-black, whichever reads on it.
    - `baseFontSize` (string, optional, one of `14px`, `15px`, `16px`, `17px`, `18px`) — Body text size; headings and buttons scale with it. Unset is `16px`.
    - `cardWidth` (string, optional, one of `560px`, `600px`, `680px`) — Width of the email card on wide screens.
    - `cardBorderRadius` (string, optional, one of `0px`, `6px`, `12px`, `16px`, `24px`, `999px`) — Corner rounding of the email's card.
    - `buttonBorderRadius` (string, optional, one of `0px`, `6px`, `12px`, `16px`, `24px`, `999px`) — Button corners; `cardBorderRadius` rounds the email's card and, when this is unset, buttons.
    - `buttonStyle` (string, optional, one of `solid`, `outline`) — Button style.
  - `language` (string, required) — The language the email is written in, as a BCP 47 tag ("en", "fr-BE", "ar"). It sets the HTML `lang` and the reading direction: Arabic, Hebrew, Persian, Urdu and other right-to-left languages render right to left. Defaults to "en".
- One of: **HtmlTemplate**
  - `id` (string, required, uuid)
  - `name` (string, required)
  - `plainTextOverride` (string | null, required) — Plain text sent instead of the version generated from the design or HTML.
  - `transactionalDefaults` (TransactionalDefaults, required) — What a transactional send of the template uses unless the send gives its own; `null` leaves it to the send. Campaigns and journeys set their own.
    - `subject` (string | null, required) — The subject line; may hold merge tags.
    - `previewText` (string | null, required) — The inbox preview text after the subject; may hold merge tags.
    - `from` (string | null, required) — The sender: one address, optionally with a display name.
    - `replyTo` (string | null, required, email) — The address replies go to.
  - `alias` (string | null, required) — The name a transactional send may use in `email.template`.
  - `publishedVersion` (integer | null, required, min > 0) — The version API sends use; null until published. The template itself is the draft.
  - `hasUnpublishedChanges` (boolean, required) — The draft differs from the published version, the brand or a shared block it places has changed since it was published, or it was never published.
  - `revision` (integer, required, min > 0, max 2147483647) — Raised by every edit. Send it back as `expectedRevision` on the update so a change made since you read it is refused instead of overwritten.
  - `thumbnailUrl` (string | null, required, uri) — A small picture of the design (WebP, 640 × 853, shown at half size), redrawn a few seconds after each save, at a new address each time; null until the first is drawn.
  - `tags` (string[], required) — Tag names, sorted without case.
  - `createdAt` (string, required, date-time)
  - `updatedAt` (string, required, date-time)
  - `kind` ("html", required) — The whole email written as HTML, kept as code.
  - `html` (string, required) — The whole email, scripts and the like removed when it was saved.