JSON Canvas by @kepano · Skillet
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.
fromNode
toNode
Validate : Parse the JSON to confirm it is valid. Verify all fromNode/toNode values exist in the nodes array
2. Add a Node to an Existing Canvas
Read and parse the existing .canvas file
Generate a unique ID that does not collide with existing node or edge IDs
Choose position (x, y) that avoids overlapping existing nodes (leave 50-100px spacing)
Append the new node object to the nodes array
Optionally add edges connecting the new node to existing nodes
Validate : Confirm all IDs are unique and all edge references resolve to existing nodes
3. Connect Two Nodes
Identify the source and target node IDs
Generate a unique edge ID
Set fromNode and toNode to the source and target IDs
Optionally set fromSide/toSide (top, right, bottom, left) for anchor points
Optionally set label for descriptive text on the edge
Append the edge to the edges array
Validate : Confirm both fromNode and toNode reference existing node IDs
4. Edit an Existing Canvas
Read and parse the .canvas file as JSON
Locate the target node or edge by id
Modify the desired attributes (text, position, color, etc.)
Write the updated JSON back to the file
Validate : Re-check all ID uniqueness and edge reference integrity after editing
Nodes Nodes are objects placed on the canvas. Array order determines z-index: first node = bottom layer, last node = top layer.
Generic Node Attributes Attribute Required Type Description idYes string Unique 16-char hex identifier typeYes string text, file, link, or groupxYes integer X position in pixels yYes integer Y position in pixels widthYes integer Width in pixels heightYes integer Height in pixels colorNo canvasColor Preset "1"-"6" or hex (e.g., "#FF0000")
Text Nodes Attribute Required Type Description textYes string Plain text with Markdown syntax
{
"id" : "6f0ad84f44ce9c17" ,
"type" : "text" ,
"x" : 0 ,
"y" : 0 ,
"width" : 400 ,
"height" : 200 ,
"text" : "# Hello World\n\nThis is **Markdown** content."
}
Newline pitfall : Use \n for line breaks in JSON strings. Do not use the literal \\n -- Obsidian renders that as the characters \ and n.
File Nodes Attribute Required Type Description fileYes string Path to file within the system subpathNo string Link to heading or block (starts with #)
{
"id" : "a1b2c3d4e5f67890" ,
"type" : "file" ,
"x" : 500 ,
"y" : 0 ,
"width" : 400 ,
"height" : 300 ,
"file" : "Attachments/diagram.png"
}
Link Nodes Attribute Required Type Description urlYes string External URL
{
"id" : "c3d4e5f678901234" ,
"type" : "link" ,
"x" : 1000 ,
"y" : 0 ,
"width" : 400 ,
"height" : 200 ,
"url" : "https://obsidian.md"
}
Group Nodes Groups are visual containers for organizing other nodes. Position child nodes inside the group's bounds.
Attribute Required Type Description labelNo string Text label for the group backgroundNo string Path to background image backgroundStyleNo string cover, ratio, or repeat
{
"id" : "d4e5f6789012345a" ,
"type" : "group" ,
"x" : -50 ,
"y" : -50 ,
"width" : 1000 ,
"height" : 600 ,
"label" : "Project Overview" ,
"color" : "4"
}
Edges Edges connect nodes via fromNode and toNode IDs.
Attribute Required Type Default Description idYes string - Unique identifier fromNodeYes string - Source node ID fromSideNo string - top, right, bottom, or leftfromEndNo string nonenone or arrowtoNodeYes string - Target node ID toSideNo string - top, right, bottom, or lefttoEndNo string arrownone or arrowcolorNo canvasColor - Line color labelNo string - Text label
{
"id" : "0123456789abcdef" ,
"fromNode" : "6f0ad84f44ce9c17" ,
"fromSide" : "right" ,
"toNode" : "a1b2c3d4e5f67890" ,
"toSide" : "left" ,
"toEnd" : "arrow" ,
"label" : "leads to"
}
Colors The canvasColor type accepts either a hex string or a preset number:
Preset Color "1"Red "2"Orange "3"Yellow "4"Green "5"Cyan "6"Purple
Preset color values are intentionally undefined -- applications use their own brand colors.
ID Generation Generate 16-character lowercase hexadecimal strings (64-bit random value):
"6f0ad84f44ce9c17"
"a3b2c1d0e9f8a7b6"
Layout Guidelines
Coordinates can be negative (canvas extends infinitely)
x increases right, y increases down; position is the top-left cornerSpace nodes 50-100px apart; leave 20-50px padding inside groups
Align to grid (multiples of 10 or 20) for cleaner layouts
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
Validation Checklist After creating or editing a canvas file, verify:
All id values are unique across both nodes and edges
Every fromNode and toNode references an existing node ID
Required fields are present for each node type (text for text nodes, file for file nodes, url for link nodes)
type is one of: text, file, link, groupfromSide/toSide values are one of: top, right, bottom, leftfromEnd/toEnd values are one of: none, arrowColor presets are "1" through "6" or valid hex (e.g., "#FF0000")
JSON is valid and parseable
If validation fails, check for duplicate IDs, dangling edge references, or malformed JSON strings (especially unescaped newlines in text content).
Complete Examples See references/EXAMPLES.md for full canvas examples including mind maps, project boards, research canvases, and flowcharts.
References ~2.2K tokens
