block-schemas

name	block-schemas
description	Formal Gutenberg block schemas for AI block generation. Contains the stripped block.json for each core block — attributes, defaults, supports, and serialization rules — plus validation notes for fields where the schema alone is ambiguous. Read this skill before generating any block markup.

Gutenberg Block Schemas

Schemas are stripped of editor-only fields (editorStyle, style, selectors, apiVersion, textdomain, usesContext, __experimentalDefaultControls). What remains is everything that affects block comment attributes and saved HTML.

How to use this skill

1. Find the block section below.
2. Read the attributes object — these are the valid keys for the block comment JSON. Only include attributes that produce HTML output.
3. Read the supports object — this tells you what style controls are available (color, spacing, typography, border, etc.).
4. Read the Validation notes — these cover edge cases where the schema alone is ambiguous or where a common mistake causes the block validator to reject the markup.
5. Generate the block comment JSON using only attributes from the schema. The HTML must match exactly what those attributes produce — any extra class, style, or element that is not derivable from the comment attributes will fail validation.

Regenerating this file

Run node generate-block-schemas.js --refresh to pull fresh schemas from the Gutenberg GitHub repository (requires network access). Run without --refresh to rebuild from the bundled snapshots (offline-safe).

---

core/paragraph

{
  "name": "core/paragraph",
  "attributes": {
    "align": {
      "type": "string"
    },
    "content": {
      "type": "rich-text",
      "source": "rich-text",
      "selector": "p"
    },
    "dropCap": {
      "type": "boolean",
      "default": false
    },
    "placeholder": {
      "type": "string"
    },
    "textColor": {
      "type": "string"
    },
    "backgroundColor": {
      "type": "string"
    },
    "fontSize": {
      "type": "string"
    },
    "direction": {
      "type": "string",
      "enum": [
        "ltr",
        "rtl"
      ]
    },
    "style": {
      "type": "object"
    }
  },
  "supports": {
    "anchor": true,
    "className": false,
    "color": {
      "gradients": true,
      "link": true
    },
    "spacing": {
      "margin": true,
      "padding": true
    },
    "typography": {
      "fontSize": true,
      "lineHeight": true,
      "__experimentalFontFamily": true,
      "__experimentalTextDecoration": true,
      "__experimentalFontStyle": true,
      "__experimentalFontWeight": true,
      "__experimentalLetterSpacing": true,
      "__experimentalTextTransform": true
    },
    "__experimentalBorder": {
      "color": true,
      "radius": true,
      "style": true,
      "width": true
    }
  }
}

Validation notes

• align is the text-alignment attribute for paragraphs (not textAlign). Valid values: "left", "center", "right".
• Named palette slugs in textColor / backgroundColor produce has-{slug}-color / has-{slug}-background-color classes. Use hex in style.color.text / style.color.background instead to avoid palette dependency.
• Inline padding goes in style.spacing.padding, not as a top-level attribute.

---

core/heading

{
  "name": "core/heading",
  "attributes": {
    "textAlign": {
      "type": "string"
    },
    "content": {
      "type": "rich-text",
      "source": "rich-text",
      "selector": "h1,h2,h3,h4,h5,h6"
    },
    "level": {
      "type": "number",
      "default": 2
    },
    "levelOptions": {
      "type": "array"
    },
    "placeholder": {
      "type": "string"
    },
    "textColor": {
      "type": "string"
    },
    "backgroundColor": {
      "type": "string"
    },
    "gradient": {
      "type": "string"
    },
    "fontSize": {
      "type": "string"
    },
    "style": {
      "type": "object"
    }
  },
  "supports": {
    "align": [
      "wide",
      "full"
    ],
    "anchor": true,
    "className": true,
    "color": {
      "gradients": true,
      "link": true
    },
    "spacing": {
      "margin": true,
      "padding": true
    },
    "typography": {
      "fontSize": true,
      "lineHeight": true,
      "__experimentalFontFamily": true,
      "__experimentalFontStyle": true,
      "__experimentalFontWeight": true,
      "__experimentalLetterSpacing": true,
      "__experimentalTextDecoration": true,
      "__experimentalTextTransform": true
    },
    "__experimentalBorder": {
      "color": true,
      "radius": true,
      "style": true,
      "width": true
    }
  }
}

Validation notes

• Use textAlign for inline text alignment ("left", "center", "right"). Use align only for layout alignment ("wide", "full"). These are different attributes — mixing them causes validation failure.
• level defaults to 2. Omit it when emitting an h2 to keep markup clean.
• Named textColor palette slug produces has-{slug}-color has-text-color classes. Use style.color.text with a hex value to avoid palette dependency.
• fontSize is a theme-registered slug (e.g. "large", "x-large"). For exact pixel sizes use style.typography.fontSize instead.

---

core/image

{
  "name": "core/image",
  "attributes": {
    "align": {
      "type": "string"
    },
    "url": {
      "type": "string",
      "source": "attribute",
      "selector": "img",
      "attribute": "src"
    },
    "alt": {
      "type": "string",
      "source": "attribute",
      "selector": "img",
      "attribute": "alt",
      "default": ""
    },
    "caption": {
      "type": "rich-text",
      "source": "rich-text",
      "selector": "figcaption"
    },
    "title": {
      "type": "string",
      "source": "attribute",
      "selector": "img",
      "attribute": "title"
    },
    "href": {
      "type": "string",
      "source": "attribute",
      "selector": "figure > a",
      "attribute": "href"
    },
    "rel": {
      "type": "string",
      "source": "attribute",
      "selector": "figure > a",
      "attribute": "rel"
    },
    "linkClass": {
      "type": "string",
      "source": "attribute",
      "selector": "figure > a",
      "attribute": "class"
    },
    "id": {
      "type": "number"
    },
    "width": {
      "type": "string"
    },
    "height": {
      "type": "string"
    },
    "aspectRatio": {
      "type": "string"
    },
    "scale": {
      "type": "string"
    },
    "sizeSlug": {
      "type": "string"
    },
    "linkDestination": {
      "type": "string"
    },
    "linkTarget": {
      "type": "string",
      "source": "attribute",
      "selector": "figure > a",
      "attribute": "target"
    }
  },
  "supports": {
    "align": true,
    "anchor": true,
    "color": {
      "text": false,
      "background": false
    },
    "filter": {
      "duotone": true
    },
    "shadow": true,
    "__experimentalBorder": {
      "color": true,
      "radius": true,
      "style": true,
      "width": true
    }
  }
}

Validation notes

• sizeSlug (e.g. "full", "large", "medium") drives the size-{slug} figure class. Always include it — omitting it makes the figure class unpredictable.
• linkDestination should always be set explicitly: "none", "media", "attachment", or "custom". Omitting it causes the validator to assume a default that may not match the rendered HTML.
• The attachment ID class wp-image-{id} goes on the <img> element, not the <figure>. Include id in attrs when you have it.
• caption is stored as an attribute AND rendered as <figcaption> — both must be present or validation fails.

---

core/cover

{
  "name": "core/cover",
  "attributes": {
    "url": {
      "type": "string"
    },
    "useFeaturedImage": {
      "type": "boolean",
      "default": false
    },
    "id": {
      "type": "number"
    },
    "alt": {
      "type": "string",
      "default": ""
    },
    "hasParallax": {
      "type": "boolean",
      "default": false
    },
    "isRepeated": {
      "type": "boolean",
      "default": false
    },
    "dimRatio": {
      "type": "number",
      "default": 100
    },
    "overlayColor": {
      "type": "string"
    },
    "customOverlayColor": {
      "type": "string"
    },
    "isUserOverlayColor": {
      "type": "boolean"
    },
    "backgroundType": {
      "type": "string",
      "default": "image"
    },
    "focalPoint": {
      "type": "object"
    },
    "minHeight": {
      "type": "number"
    },
    "minHeightUnit": {
      "type": "string"
    },
    "gradient": {
      "type": "string"
    },
    "customGradient": {
      "type": "string"
    },
    "contentPosition": {
      "type": "string"
    },
    "isDark": {
      "type": "boolean",
      "default": true
    },
    "templateLock": {
      "type": [
        "string",
        "boolean"
      ],
      "enum": [
        "all",
        "insert",
        "contentOnly",
        false
      ]
    },
    "tagName": {
      "type": "string",
      "default": "div"
    },
    "sizeSlug": {
      "type": "string"
    },
    "poster": {
      "type": "string",
      "source": "attribute",
      "selector": "video",
      "attribute": "poster"
    }
  },
  "supports": {
    "anchor": true,
    "align": true,
    "html": false,
    "shadow": true,
    "spacing": {
      "padding": true,
      "margin": [
        "top",
        "bottom"
      ],
      "blockGap": true
    },
    "__experimentalBorder": {
      "color": true,
      "radius": true,
      "style": true,
      "width": true
    },
    "color": {
      "heading": true,
      "text": true,
      "background": false,
      "__experimentalSkipSerialization": [
        "gradients"
      ],
      "enableContrastChecker": false
    },
    "dimensions": {
      "aspectRatio": true
    },
    "typography": {
      "fontSize": true,
      "lineHeight": true,
      "__experimentalFontFamily": true,
      "__experimentalFontWeight": true,
      "__experimentalFontStyle": true,
      "__experimentalTextTransform": true,
      "__experimentalTextDecoration": true,
      "__experimentalLetterSpacing": true
    },
    "layout": {
      "allowJustification": false
    },
    "filter": {
      "duotone": true
    },
    "allowedBlocks": true
  }
}

Validation notes

• Use customOverlayColor (hex string) instead of overlayColor (palette slug). overlayColor requires the theme to register that palette name — it will cause a validation failure on themes that don't. customOverlayColor works everywhere.
• dimRatio defaults to 100 (fully opaque overlay). The has-background-dim-{N} HTML class uses the value rounded to the nearest 10. Store the exact value in the attr; the class uses the rounded step.
• minHeight and minHeightUnit must both be set. The inline style value must exactly match {minHeight}{minHeightUnit} (e.g. attr 600 + "px" → style "600px").
• isDark defaults to true — Gutenberg expects light-coloured inner content when this is true. Set to false when using a light overlay so inner text can be dark.
• contentPosition controls inner content alignment. Valid values: "top left", "top center", "top right", "center left", "center center", "center right", "bottom left", "bottom center", "bottom right".
• color.__experimentalSkipSerialization: ["gradients"] means gradient values are NOT auto-serialized into classes by the style engine — the cover block handles gradient output itself. Do not add gradient classes manually.
• backgroundType defaults to "image". Set to "video" when using a video URL. When "video", the media element is <video> not <img>.
• poster is sourced from the <video poster="..."> HTML attribute, not from the block comment JSON. If you need a poster, set it as an HTML attribute on the video element.
• The overlay <span> must carry both has-background-dim and has-background-dim-{step} classes, plus style="background-color:{hex}" when using customOverlayColor.

---

core/group

{
  "name": "core/group",
  "attributes": {
    "tagName": {
      "type": "string",
      "default": "div"
    },
    "templateLock": {
      "type": [
        "string",
        "boolean"
      ],
      "enum": [
        "all",
        "insert",
        "contentOnly",
        false
      ]
    },
    "allowedBlocks": {
      "type": "array"
    },
    "style": {
      "type": "object"
    },
    "backgroundColor": {
      "type": "string"
    },
    "textColor": {
      "type": "string"
    },
    "gradient": {
      "type": "string"
    }
  },
  "supports": {
    "align": [
      "wide",
      "full"
    ],
    "anchor": true,
    "ariaLabel": true,
    "html": false,
    "color": {
      "gradients": true,
      "link": true,
      "heading": true,
      "button": true
    },
    "spacing": {
      "margin": [
        "top",
        "bottom"
      ],
      "padding": true,
      "blockGap": true
    },
    "dimensions": {
      "minHeight": true
    },
    "layout": {
      "allowSwitching": false,
      "allowInheriting": false,
      "allowEditing": true,
      "default": {
        "type": "constrained"
      }
    },
    "typography": {
      "fontSize": true,
      "lineHeight": true,
      "__experimentalFontFamily": true,
      "__experimentalFontStyle": true,
      "__experimentalFontWeight": true,
      "__experimentalLetterSpacing": true,
      "__experimentalTextDecoration": true,
      "__experimentalTextTransform": true
    },
    "__experimentalBorder": {
      "color": true,
      "radius": true,
      "style": true,
      "width": true
    },
    "shadow": true,
    "background": {
      "backgroundImage": true,
      "backgroundSize": true
    }
  }
}

Validation notes

• tagName defaults to "div". Common alternatives: "section", "article", "aside", "header", "footer", "main". Always declare it explicitly if not "div" so the validator knows what wrapper to expect.
• Custom hex background goes in style.color.background (produces inline style). Named palette slug goes in backgroundColor (produces palette class). Never mix both for the same block.
• Padding goes in style.spacing.padding as an object: {"top":"48px","right":"40px","bottom":"48px","left":"40px"}. The inline style is generated from this automatically.
• layout controls inner block flow. For a constrained centered layout: {"type":"constrained"}. For full-width flex: {"type":"flex","flexWrap":"nowrap"}.

---

core/columns

{
  "name": "core/columns",
  "attributes": {
    "verticalAlignment": {
      "type": "string"
    },
    "isStackedOnMobile": {
      "type": "boolean",
      "default": true
    },
    "templateLock": {
      "type": [
        "string",
        "boolean"
      ],
      "enum": [
        "all",
        "insert",
        "contentOnly",
        false
      ]
    },
    "allowedBlocks": {
      "type": "array"
    },
    "style": {
      "type": "object"
    },
    "backgroundColor": {
      "type": "string"
    },
    "textColor": {
      "type": "string"
    },
    "gradient": {
      "type": "string"
    }
  },
  "supports": {
    "anchor": true,
    "align": [
      "wide",
      "full"
    ],
    "html": false,
    "color": {
      "gradients": true,
      "link": true,
      "heading": true
    },
    "spacing": {
      "blockGap": {
        "top": true,
        "left": true
      },
      "margin": [
        "top",
        "bottom"
      ],
      "padding": true
    },
    "layout": {
      "allowSwitching": false,
      "allowInheriting": false,
      "allowEditing": false,
      "default": {
        "type": "flex",
        "flexWrap": "nowrap"
      }
    },
    "typography": {
      "fontSize": true,
      "lineHeight": true,
      "__experimentalFontFamily": true,
      "__experimentalFontStyle": true,
      "__experimentalFontWeight": true,
      "__experimentalLetterSpacing": true,
      "__experimentalTextDecoration": true,
      "__experimentalTextTransform": true
    },
    "__experimentalBorder": {
      "color": true,
      "radius": true,
      "style": true,
      "width": true
    },
    "shadow": true
  }
}

Validation notes

• isStackedOnMobile defaults to true. Always declare it explicitly so the validator output is deterministic.
• Column widths go on the individual core/column children via their width attribute, not on core/columns.
• Custom hex background follows the same rule as core/group: hex → style.color.background, palette slug → backgroundColor.
• Padding goes in style.spacing.padding. Column gap goes in style.spacing.blockGap.
• The wrapper div class is wp-block-columns plus optional alignwide / alignfull from the align attr.

---

core/column

{
  "name": "core/column",
  "attributes": {
    "verticalAlignment": {
      "type": "string"
    },
    "width": {
      "type": "string"
    },
    "allowedBlocks": {
      "type": "array"
    },
    "templateLock": {
      "type": [
        "string",
        "boolean"
      ],
      "enum": [
        "all",
        "insert",
        "contentOnly",
        false
      ]
    },
    "style": {
      "type": "object"
    },
    "backgroundColor": {
      "type": "string"
    },
    "textColor": {
      "type": "string"
    },
    "gradient": {
      "type": "string"
    }
  },
  "supports": {
    "anchor": true,
    "ariaLabel": true,
    "color": {
      "gradients": true,
      "link": true,
      "heading": true
    },
    "spacing": {
      "blockGap": true,
      "padding": true
    },
    "layout": {
      "allowSwitching": false,
      "allowInheriting": false,
      "default": {
        "type": "flow"
      }
    },
    "typography": {
      "fontSize": true,
      "lineHeight": true,
      "__experimentalFontFamily": true,
      "__experimentalFontStyle": true,
      "__experimentalFontWeight": true,
      "__experimentalLetterSpacing": true,
      "__experimentalTextDecoration": true,
      "__experimentalTextTransform": true
    },
    "__experimentalBorder": {
      "color": true,
      "radius": true,
      "style": true,
      "width": true
    },
    "shadow": true,
    "html": false
  }
}

Validation notes

• width drives the flex-basis inline style on the wrapper div. The value must include a unit: "33.33%", "50%", "400px". The stored attr value and the inline style value must match exactly.
• verticalAlignment produces an is-vertically-aligned-{value} class. Valid values: "top", "center", "bottom".
• Omitting width on all columns produces equal-width columns (browser default flex behaviour). Only set width when you need unequal columns.

---

core/buttons

{
  "name": "core/buttons",
  "attributes": {
    "style": {
      "type": "object"
    }
  },
  "supports": {
    "anchor": true,
    "align": [
      "wide",
      "full"
    ],
    "html": false,
    "color": {
      "gradients": false
    },
    "spacing": {
      "blockGap": true,
      "margin": [
        "top",
        "bottom"
      ],
      "padding": true
    },
    "typography": {
      "fontSize": true,
      "lineHeight": true,
      "__experimentalFontFamily": true,
      "__experimentalFontStyle": true,
      "__experimentalFontWeight": true,
      "__experimentalLetterSpacing": true,
      "__experimentalTextTransform": true,
      "__experimentalTextDecoration": true
    },
    "__experimentalBorder": {
      "radius": true
    },
    "layout": {
      "default": {
        "type": "flex",
        "justifyContent": "left"
      }
    }
  }
}

Validation notes

• layout should always be set. Default flex layout: {"type":"flex","justifyContent":"center"}. Other justification values: "left", "right", "space-between".
• Individual button blocks go inside as core/button children — they are inner blocks, not an attribute.
• No colour attributes belong on the core/buttons wrapper — colours go on each core/button child.

---

core/button

{
  "name": "core/button",
  "attributes": {
    "tagName": {
      "type": "string",
      "enum": [
        "a",
        "button"
      ],
      "default": "a"
    },
    "textAlign": {
      "type": "string"
    },
    "url": {
      "type": "string",
      "source": "attribute",
      "selector": "a",
      "attribute": "href"
    },
    "title": {
      "type": "string",
      "source": "attribute",
      "selector": "a",
      "attribute": "title"
    },
    "text": {
      "type": "rich-text",
      "source": "rich-text",
      "selector": "a,button"
    },
    "linkTarget": {
      "type": "string",
      "source": "attribute",
      "selector": "a",
      "attribute": "target"
    },
    "rel": {
      "type": "string",
      "source": "attribute",
      "selector": "a",
      "attribute": "rel"
    },
    "placeholder": {
      "type": "string"
    },
    "backgroundColor": {
      "type": "string"
    },
    "textColor": {
      "type": "string"
    },
    "gradient": {
      "type": "string"
    },
    "width": {
      "type": "number"
    },
    "style": {
      "type": "object"
    }
  },
  "supports": {
    "anchor": true,
    "color": {
      "gradients": true,
      "__experimentalSkipSerialization": true,
      "text": true,
      "background": true
    },
    "typography": {
      "fontSize": true,
      "lineHeight": true,
      "__experimentalFontFamily": true,
      "__experimentalFontStyle": true,
      "__experimentalFontWeight": true,
      "__experimentalLetterSpacing": true,
      "__experimentalTextDecoration": true,
      "__experimentalTextTransform": true
    },
    "__experimentalBorder": {
      "color": true,
      "radius": true,
      "style": true,
      "width": true,
      "__experimentalSkipSerialization": true
    },
    "html": false,
    "shadow": {
      "__experimentalSkipSerialization": true
    },
    "spacing": {
      "padding": [
        "horizontal",
        "vertical"
      ],
      "__experimentalSkipSerialization": true
    }
  },
  "styles": [
    {
      "name": "fill",
      "label": "Fill",
      "isDefault": true
    },
    {
      "name": "outline",
      "label": "Outline"
    }
  ]
}

Validation notes

• backgroundColor / textColor: use palette slugs for theme colours (produces has-{slug}-background-color class), OR use style.color.background / style.color.text for hex values (produces inline style). Never mix both approaches for the same property.
• Outline style: set className: "is-style-outline". The wrapper div gets class wp-block-button is-style-outline. Outline buttons MUST have textColor or style.color.text set — otherwise the text is invisible.
• linkTarget is "_blank" for new tab. When "_blank", rel should be "noreferrer noopener" for security.
• width is a percentage for full-width buttons: 25, 50, 75, or 100. Produces has-custom-width wp-block-button__width-{value} classes.
• The <a> tag must carry wp-block-button__link wp-element-button classes always, plus any colour classes derived from attrs.

---

core/list

{
  "name": "core/list",
  "attributes": {
    "ordered": {
      "type": "boolean",
      "default": false
    },
    "values": {
      "type": "string",
      "source": "raw",
      "selector": "ol,ul",
      "default": ""
    },
    "type": {
      "type": "string"
    },
    "start": {
      "type": "number"
    },
    "reversed": {
      "type": "boolean"
    },
    "placeholder": {
      "type": "string"
    },
    "style": {
      "type": "object"
    },
    "backgroundColor": {
      "type": "string"
    },
    "textColor": {
      "type": "string"
    },
    "gradient": {
      "type": "string"
    },
    "fontSize": {
      "type": "string"
    }
  },
  "supports": {
    "anchor": true,
    "className": true,
    "color": {
      "gradients": true,
      "link": true
    },
    "spacing": {
      "padding": true,
      "margin": true
    },
    "typography": {
      "fontSize": true,
      "lineHeight": true,
      "__experimentalFontFamily": true,
      "__experimentalFontStyle": true,
      "__experimentalFontWeight": true,
      "__experimentalLetterSpacing": true,
      "__experimentalTextDecoration": true,
      "__experimentalTextTransform": true
    },
    "__experimentalBorder": {
      "color": true,
      "radius": true,
      "style": true,
      "width": true
    }
  }
}

Validation notes

• Since WordPress 6.0, list items are inner blocks (core/list-item), not bare <li> tags. Bare <li> without block comment delimiters are parsed as a Classic block.
• ordered defaults to false (unordered list). Set to true for <ol>.
• start sets the starting number for ordered lists.
• reversed reverses the count direction for ordered lists.
• Each item needs: <!-- wp:list-item --><li>content</li><!-- /wp:list-item -->

---

core/list-item

{
  "name": "core/list-item",
  "attributes": {
    "placeholder": {
      "type": "string"
    },
    "content": {
      "type": "rich-text",
      "source": "rich-text",
      "selector": "li"
    },
    "style": {
      "type": "object"
    },
    "backgroundColor": {
      "type": "string"
    },
    "textColor": {
      "type": "string"
    },
    "fontSize": {
      "type": "string"
    }
  },
  "supports": {
    "className": false,
    "color": {
      "gradients": true,
      "link": true,
      "background": true,
      "text": true
    },
    "typography": {
      "fontSize": true,
      "lineHeight": true,
      "__experimentalFontFamily": true,
      "__experimentalFontStyle": true,
      "__experimentalFontWeight": true,
      "__experimentalLetterSpacing": true,
      "__experimentalTextDecoration": true,
      "__experimentalTextTransform": true
    }
  }
}

Validation notes

• Must always appear as a direct child of core/list.
• content is the item text — may contain inline HTML.
• Can contain a nested core/list as an inner block for sub-lists.

---

core/separator

{
  "name": "core/separator",
  "attributes": {
    "opacity": {
      "type": "string",
      "default": "alpha-channel"
    },
    "backgroundColor": {
      "type": "string"
    },
    "gradient": {
      "type": "string"
    },
    "style": {
      "type": "object"
    }
  },
  "supports": {
    "anchor": true,
    "align": [
      "center",
      "wide",
      "full"
    ],
    "color": {
      "enableContrastChecker": false,
      "gradients": true
    },
    "spacing": {
      "margin": [
        "top",
        "bottom"
      ]
    }
  },
  "styles": [
    {
      "name": "default",
      "label": "Default",
      "isDefault": true
    },
    {
      "name": "wide",
      "label": "Wide Line"
    },
    {
      "name": "dots",
      "label": "Dots"
    }
  ]
}

Validation notes

• Default (no attrs) renders <hr class="wp-block-separator has-alpha-channel-opacity"/>.
• Custom colour goes in style.color.background (hex). This produces both background-color and color inline styles on the <hr> — both are required for the validator.
• Named palette colours go in backgroundColor — produces has-{slug}-background-color has-background classes.
• align: "full" produces alignfull class and removes the default max-width.
• The opacity attribute controls the CSS opacity class: "css" → has-css-opacity, omitted → has-alpha-channel-opacity.

---

core/spacer

{
  "name": "core/spacer",
  "attributes": {
    "height": {
      "type": "string",
      "default": "100px"
    },
    "width": {
      "type": "string"
    },
    "style": {
      "type": "object"
    }
  },
  "supports": {
    "anchor": true
  }
}

Validation notes

• height is required and must include a unit: "48px", "10vh", etc. The inline style value must match the attr value exactly.
• width is only relevant when the spacer is inside a flex layout.
• The wrapper is <div style="height:{value}" aria-hidden="true" class="wp-block-spacer">.

---

core/quote

{
  "name": "core/quote",
  "attributes": {
    "value": {
      "type": "string",
      "source": "html",
      "selector": "blockquote",
      "multiline": "p",
      "default": ""
    },
    "citation": {
      "type": "rich-text",
      "source": "rich-text",
      "selector": "cite"
    },
    "textAlign": {
      "type": "string"
    },
    "backgroundColor": {
      "type": "string"
    },
    "textColor": {
      "type": "string"
    },
    "gradient": {
      "type": "string"
    },
    "fontSize": {
      "type": "string"
    },
    "style": {
      "type": "object"
    }
  },
  "supports": {
    "align": [
      "left",
      "right",
      "wide",
      "full"
    ],
    "anchor": true,
    "color": {
      "gradients": true,
      "link": true,
      "heading": true
    },
    "typography": {
      "fontSize": true,
      "lineHeight": true,
      "__experimentalFontFamily": true,
      "__experimentalFontStyle": true,
      "__experimentalFontWeight": true,
      "__experimentalLetterSpacing": true,
      "__experimentalTextDecoration": true,
      "__experimentalTextTransform": true
    },
    "spacing": {
      "blockGap": true,
      "padding": true,
      "margin": true
    },
    "__experimentalBorder": {
      "color": true,
      "radius": true,
      "style": true,
      "width": true
    }
  },
  "styles": [
    {
      "name": "default",
      "label": "Default",
      "isDefault": true
    },
    {
      "name": "plain",
      "label": "Plain"
    }
  ]
}

Validation notes

• The quote text goes as an inner core/paragraph block — it is NOT a direct attribute. The <blockquote> contains the paragraph block comment and HTML.
• citation (not "cite") is the attribute name for the attribution text. It renders as a <cite> element inside the <blockquote>.
• textAlign aligns the quote text. Valid values: "left", "center", "right".
• Style variants: default, "large" (is-style-large). Set via className.

---