git clone https://github.com/NeverSight/learn-skills.dev
T=$(mktemp -d) && git clone --depth=1 https://github.com/NeverSight/learn-skills.dev "$T" && mkdir -p ~/.claude/skills && cp -r "$T/data/skills-md/acquia/nebula/canvas-component-metadata" ~/.claude/skills/neversight-learn-skills-dev-canvas-component-metadata && rm -rf "$T"
data/skills-md/acquia/nebula/canvas-component-metadata/SKILL.mdFile structure
Every
component.yml must include these top-level keys:
name: Component Name # Human-readable display name machineName: component-name # Machine name in kebab-case status: true # Whether the component is enabled required: [] # Array of required prop names props: properties: # ... prop definitions slots: [] # Use [] only when there are no slots; otherwise use an object map
Props
Requirements
Every prop definition must include a
title for the UI label. The examples
array is required for required props and recommended for all others. Only the
first example value is used by Drupal Canvas.
props: properties: heading: title: Heading type: string examples: - Enter a heading...
Prop IDs must be camelCase versions of their titles.
The prop ID (the key under
properties) must be the camelCase conversion of the
title value.
Only include user-facing, Canvas-editable props in
component.yml.
Implementation-only React props must stay in JSX and must not be added to
metadata.
Never include
in className
. Treat it as a composition prop
for developers, not a Canvas editor control.component.yml
# Correct props: properties: buttonText: # camelCase of "Button Text" title: Button Text type: string backgroundColor: # camelCase of "Background Color" title: Background Color type: string isVisible: # camelCase of "Is Visible" title: Is Visible type: boolean # Wrong props: properties: btn_text: # should be "buttonText" for title "Button Text" title: Button Text bgColor: # should be "backgroundColor" for title "Background Color" title: Background Color
Prop types
Text
Basic text input. Stored as a string value.
type: string examples: - Hello, world!
Formatted text
Rich text content with HTML formatting support, displayed in a block context.
type: string contentMediaType: text/html x-formatting-context: block examples: - <p>This is <strong>formatted</strong> text with HTML.</p>
Link
URL or URI reference for links to internal or external resources.
type: string format: uri-reference examples: - /about/contact
Note: The format can be either
uri (accepts only absolute URLs) or
uri-reference (accepts both absolute and relative URLs).
IMPORTANT: Use proper path examples for URL props. Do not use
# as an
example value for uri-reference props—it can cause validation failures during
upload. Always use realistic path-like examples:
# Correct examples: - /resources - /about/team - https://example.com/page # Wrong examples: - "#" - ""
Image
Reference to an image object with metadata like alt text, dimensions, and file URL. Only the file URL is required to exist, all other metadata is always optional.
type: object $ref: json-schema-definitions://canvas.module/image examples: - src: >- https://images.unsplash.com/photo-1484959014842-cd1d967a39cf?ixlib=rb-1.2.1&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=1770&q=80 alt: Woman playing the violin width: 1770 height: 1180
Video
Reference to a video object with metadata like dimensions and file URL. Only the file URL is required to exist, all other metadata is always optional.
type: object $ref: json-schema-definitions://canvas.module/video examples: - src: https://media.istockphoto.com/id/1340051874/video/aerial-top-down-view-of-a-container-cargo-ship.mp4?s=mp4-640x640-is&k=20&c=5qPpYI7TOJiOYzKq9V2myBvUno6Fq2XM3ITPGFE8Cd8= poster: https://example.com/600x400.png
Boolean
True or false value.
type: boolean examples: - false
Integer
Whole number value without decimal places.
type: integer examples: - 42
Number
Numeric value that can include decimal places.
type: number examples: - 3.14
List: text
A predefined list of text options that the user can select from.
type: string enum: - option1 - option2 - option3 meta:enum: option1: Option 1 option2: Option 2 option3: Option 3 examples: - option1
List: integer
A predefined list of integer options that the user can select from.
type: integer enum: - 1 - 2 - 3 meta:enum: 1: Option 1 2: Option 2 3: Option 3 examples: - 1
Enums
Enum values must use lowercase, machine-friendly identifiers. Use
meta:enum to
provide human-readable display labels for the UI.
Note: Enum values cannot contain dots.
# Correct enum: - left_aligned - center_aligned meta:enum: left_aligned: Left aligned center_aligned: Center aligned examples: - left_aligned # Wrong enum: - Left aligned - Center aligned
The
examples value must be the enum value, not the display label.
Enum values must match JSX component variants
When using class-variance-authority (CVA) or similar libraries in the JSX component, the variant keys must exactly match the enum values defined in
component.yml.
// component.yml defines: enum: [left_aligned, center_aligned] // CVA variants must match: const variants = cva("base-classes", { variants: { layout: { left_aligned: "text-left", // matches enum value center_aligned: "text-center", // matches enum value }, }, });
Slots
Slots allow other components to be embedded within a component. In React, each slot is received as a named prop that matches the slot key.
This section is the slot schema source of truth. Other skills should reference these rules instead of redefining slot schema details.
Before creating slots, confirm with the user unless the use case is clearly compositional (for example, rich nested content, or repeatable embedded components). For simple text-like values, prefer a prop.
Important: Do not map Canvas slots to the
children prop by default. If the
slot key is content, consume it as content in JSX.
Using a slot key named
children is technically possible, but it is not
recommended because slot naming often flows into user-facing Canvas labels.
Prefer explicit slot keys such as content, media, or actions.
slots must be either:
- An object map keyed by slot name (
,content
, etc.)sidebar
when the component has no slots[]
slots: content: title: Content buttons: title: Buttons
In the JSX component, slots are destructured as named props and rendered directly:
const Section = ({ width, content }) => { return <div className={sectionVariants({ width })}>{content}</div>; };
// Wrong when the slot key is `content`: this does not consume the named slot. const Section = ({ children }) => { return <div>{children}</div>; };
Use
slots: [] only when the component has no slots:
slots: []
Do not use arrays of slot objects:
# Wrong slots: - name: content title: Content