Antigravity-awesome-skills 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.

install
source · Clone the upstream repo
git clone https://github.com/sickn33/antigravity-awesome-skills
Claude Code · Install into ~/.claude/skills/
T=$(mktemp -d) && git clone --depth=1 https://github.com/sickn33/antigravity-awesome-skills "$T" && mkdir -p ~/.claude/skills && cp -r "$T/plugins/antigravity-awesome-skills-claude/skills/json-canvas" ~/.claude/skills/sickn33-antigravity-awesome-skills-json-canvas && rm -rf "$T"
manifest: plugins/antigravity-awesome-skills-claude/skills/json-canvas/SKILL.md
source content

JSON Canvas Skill

When to Use

  • Use when creating or editing
    .canvas
    files for Obsidian.
  • Use for mind maps, flowcharts, visual note structures, or connected canvases.
  • Use when the user explicitly mentions JSON Canvas or Obsidian Canvas files.

File Structure

A canvas file (

.canvas
) contains two top-level arrays following the JSON Canvas Spec 1.0:

{
  "nodes": [],
  "edges": []
}
  • nodes
    (optional): Array of node objects
  • edges
    (optional): Array of edge objects connecting nodes

Common Workflows

1. Create a New Canvas

  1. Create a
    .canvas
    file with the base structure
    {"nodes": [], "edges": []}
  2. Generate unique 16-character hex IDs for each node (e.g.,
    "6f0ad84f44ce9c17"
    )
  3. Add nodes with required fields:
    id
    ,
    type
    ,
    x
    ,
    y
    ,
    width
    ,
    height
  4. Add edges referencing valid node IDs via
    fromNode
    and
    toNode
  5. 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

  1. Read and parse the existing
    .canvas
    file
  2. Generate a unique ID that does not collide with existing node or edge IDs
  3. Choose position (
    x
    ,
    y
    ) that avoids overlapping existing nodes (leave 50-100px spacing)
  4. Append the new node object to the
    nodes
    array
  5. Optionally add edges connecting the new node to existing nodes
  6. Validate: Confirm all IDs are unique and all edge references resolve to existing nodes

3. Connect Two Nodes

  1. Identify the source and target node IDs
  2. Generate a unique edge ID
  3. Set
    fromNode
    and
    toNode
    to the source and target IDs
  4. Optionally set
    fromSide
    /
    toSide
    (top, right, bottom, left) for anchor points
  5. Optionally set
    label
    for descriptive text on the edge
  6. Append the edge to the
    edges
    array
  7. Validate: Confirm both
    fromNode
    and
    toNode
    reference existing node IDs

4. Edit an Existing Canvas

  1. Read and parse the
    .canvas
    file as JSON
  2. Locate the target node or edge by
    id
  3. Modify the desired attributes (text, position, color, etc.)
  4. Write the updated JSON back to the file
  5. 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

AttributeRequiredTypeDescription
id
YesstringUnique 16-char hex identifier
type
Yesstring
text
,
file
,
link
, or
group
x
YesintegerX position in pixels
y
YesintegerY position in pixels
width
YesintegerWidth in pixels
height
YesintegerHeight in pixels
color
NocanvasColorPreset
"1"
-
"6"
or hex (e.g.,
"#FF0000"
)

Text Nodes

AttributeRequiredTypeDescription
text
YesstringPlain 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

AttributeRequiredTypeDescription
file
YesstringPath to file within the system
subpath
NostringLink to heading or block (starts with
#
)
{
  "id": "a1b2c3d4e5f67890",
  "type": "file",
  "x": 500,
  "y": 0,
  "width": 400,
  "height": 300,
  "file": "Attachments/diagram.png"
}

Link Nodes

AttributeRequiredTypeDescription
url
YesstringExternal 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.

AttributeRequiredTypeDescription
label
NostringText label for the group
background
NostringPath to background image
backgroundStyle
Nostring
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.

AttributeRequiredTypeDefaultDescription
id
Yesstring-Unique identifier
fromNode
Yesstring-Source node ID
fromSide
Nostring-
top
,
right
,
bottom
, or
left
fromEnd
Nostring
none
none
or
arrow
toNode
Yesstring-Target node ID
toSide
Nostring-
top
,
right
,
bottom
, or
left
toEnd
Nostring
arrow
none
or
arrow
color
NocanvasColor-Line color
label
Nostring-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:

PresetColor
"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 corner
  • Space nodes 50-100px apart; leave 20-50px padding inside groups
  • Align to grid (multiples of 10 or 20) for cleaner layouts
Node TypeSuggested WidthSuggested Height
Small text200-30080-150
Medium text300-450150-300
Large text400-600300-500
File preview300-500200-400
Link preview250-400100-200

Validation Checklist

After creating or editing a canvas file, verify:

  1. All
    id
    values are unique across both nodes and edges
  2. Every
    fromNode
    and
    toNode
    references an existing node ID
  3. Required fields are present for each node type (
    text
    for text nodes,
    file
    for file nodes,
    url
    for link nodes)
  4. type
    is one of:
    text
    ,
    file
    ,
    link
    ,
    group
  5. fromSide
    /
    toSide
    values are one of:
    top
    ,
    right
    ,
    bottom
    ,
    left
  6. fromEnd
    /
    toEnd
    values are one of:
    none
    ,
    arrow
  7. Color presets are
    "1"
    through
    "6"
    or valid hex (e.g.,
    "#FF0000"
    )
  8. 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

Limitations

  • Use this skill only when the task clearly matches the scope described above.
  • Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
  • Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.