json-canvas
Create and edit JSON Canvas files (.canvas) with nodes, edges, groups, and connections. Use when working with .canvas files, creating visual canvases, mind maps, flowcharts, or when the user mentions Canvas files in Obsidian.
By freestylefly · 472 installs
npx skills add freestylefly/canghe-skills --skill json-canvas
Source repository · Upstream listing
JSON Canvas Skill
This skill enables skills compatible agents to create and edit valid JSON Canvas files ( .canvas ) used in Obsidian and other applications.
Overview
JSON Canvas is an open file format for infinite canvas data. Canvas files use the .canvas extension and contain valid JSON following the [JSON Canvas Spec 1.0](https://jsoncanvas.org/spec/1.0/).
File Structure
A canvas file contains two top level arrays:
nodes (optional): Array of node objects
edges (optional): Array of edge objects connecting nodes
Nodes
Nodes are objects placed on the canvas. There are four node types:
text Text content with Markdown
file Reference to files/attachments
link External URL
group Visual container for other nodes
Z Index Ordering
Nodes are ordered by z index in the array:
First node = bottom layer (displayed below others)
Last node = top layer (displayed above others)
Generic Node Attributes
All nodes share these attributes:
Attribute Required Type Description
id Yes string Unique identifier for the node
type Yes string Node type: text , file , link , or group
x Yes integer X position in pixels
y Yes integer Y position in pixels
width Yes integer Width in pixels
height Yes integer Height in pixels
color No canvasColor Node color (see Color section)
Text Nodes
Text nodes contain Markdown content.
Attribute Required Type Description
text Yes string Plain text with Markdown syntax
File Nodes
File nodes reference files or attachments (images, videos, PDFs, notes, etc.).
Attribute Required Type Description
file Yes string Path to file within the system
subpath No string Link to heading or block (starts with )
Link Nodes
Link nodes display external URLs.
Attribute Required Type Description
url Yes string External URL
Group Nodes
Group nodes are visual containers for organizing other nodes.
Attribute Required Type Description
label No string Text label for the group
background No string Path to background image
backgroundStyle No string Background rendering style
Background Styles
Value Description
cover Fills entire width and height of node
ratio Maintains aspect ratio of background image
repeat Repeats image as pattern in both directions
Edges
Edges are lines connecting nodes.
Attribute Required Type Default Description
id Yes string Unique identifier for the edge
fromNode Yes string Node ID where connection starts
fromSide No string Side where edge starts
fromEnd No string none Shape at edge start
toNode Yes string Node ID where connection ends
toSide No string Side where edge ends
toEnd No string arrow Shape at edge end
color No canvasColor Line color
label No string Text label for the edge
Side Values
Value Description
top Top edge of node
right Right edge of node
bottom Bottom edge of node
left Left edge of node
End Shapes
Value Description
none No endpoint shape
arrow Arrow endpoint
Colors
The canvasColor type can be specified in two ways:
Hex Colors
Preset Colors
Preset Color
"1" Red
"2" Orange
"3" Yellow
"4" Green
"5" Cyan
"6" Purple
Note: Specific color values for presets are intentionally undefined, allowing applications to use their own brand colors.
Complete Examples
Simple Canvas with Text and Connections
Project Board with Groups
Research Canvas with Files and Links
Flowchart
ID Generation
Node and edge IDs must be unique strings. Obsidian generates 16 character hexadecimal IDs:
This format is a 16 character lowercase hex string (64 bit random value).
Layout Guidelines
Positioning
Coordinates can be negative (canvas extends infinitely)
x increases to the right
y increases downward
Position refers to top left corner of node
Recommended Sizes
Node Type Suggested Width Suggested Height
Small text 200 300 80 150
Medium text 300 450 150 300
Large text 400 600 300 500
File preview 300 500 200 400
Link preview 250 400 100 200
Group Varies Varies
Spacing
Leave 20 50px padding inside groups
Space nodes 50 100px apart for readability
Align nodes to grid (multiples of 10 or 20) for cleaner layouts
Validation Rules
1. All id values must be unique across nodes and edges
2. fromNode and toNode must reference existing node IDs
3. Required fields must be present for each node type
4. type must be one of: text , file , link , group
5. backgroundStyle must be one of: cover , ratio , repeat
6. fromSide , toSide must be one of: top , right , bottom , left
7. fromEnd , toEnd must be one of: none , arrow
8. Color presets must be "1" through "6" or valid hex color
References
[JSON Canvas Spec 1.0](https://jsoncanvas.org/spec/1.0/)
[JSON Canvas GitHub](https://github.com/obsidianmd/jsoncanvas)