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JSON Canvas Agent Skill

by anbeime

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.

4k tokens
context cost
the whole folder, loaded on every use
1
files
instructions only
0
copies elsewhere
how many repositories repackaged it
4658
stars on the repo
on the repository, not the skill itself

Install

one command, takes just this skill from the repository 
npx skills add https://github.com/anbeime/skill --skill json-canvas

The instruction itself

30 sections, as written by the author

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.

File Structure

A canvas file contains two top-level arrays:

{
  "nodes": [],
  "edges": []
}
  • 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.

{
  "id": "6f0ad84f44ce9c17",
  "type": "text",
  "x": 0,
  "y": 0,
  "width": 400,
  "height": 200,
  "text": "# Hello World\n\nThis is **Markdown** content."
}
Newline Escaping (Common Pitfall)

In JSON, newline characters inside strings must be represented as \n. Do not use the literal sequence \\n in a .canvas file—Obsidian will render it as the characters \ and n instead of a line break.

Examples:

{ "type": "text", "text": "Line 1\nLine 2" }

{ "type": "text", "text": "Line 1\\nLine 2" }

| 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.).

{
  "id": "a1b2c3d4e5f67890",
  "type": "file",
  "x": 500,
  "y": 0,
  "width": 400,
  "height": 300,
  "file": "Attachments/diagram.png"
}

{
  "id": "b2c3d4e5f6789012",
  "type": "file",
  "x": 500,
  "y": 400,
  "width": 400,
  "height": 300,
  "file": "Notes/Project Overview.md",
  "subpath": "#Implementation"
}

| 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.

{
  "id": "c3d4e5f678901234",
  "type": "link",
  "x": 1000,
  "y": 0,
  "width": 400,
  "height": 200,
  "url": "https://obsidian.md"
}

| Attribute | Required | Type | Description |

|-----------|----------|------|-------------|

| url | Yes | string | External URL |

Group Nodes

Group nodes are visual containers for organizing other nodes.

{
  "id": "d4e5f6789012345a",
  "type": "group",
  "x": -50,
  "y": -50,
  "width": 1000,
  "height": 600,
  "label": "Project Overview",
  "color": "4"
}

{
  "id": "e5f67890123456ab",
  "type": "group",
  "x": 0,
  "y": 700,
  "width": 800,
  "height": 500,
  "label": "Resources",
  "background": "Attachments/background.png",
  "backgroundStyle": "cover"
}

| 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.

{
  "id": "f67890123456789a",
  "fromNode": "6f0ad84f44ce9c17",
  "toNode": "a1b2c3d4e5f67890"
}

{
  "id": "0123456789abcdef",
  "fromNode": "6f0ad84f44ce9c17",
  "fromSide": "right",
  "fromEnd": "none",
  "toNode": "b2c3d4e5f6789012",
  "toSide": "left",
  "toEnd": "arrow",
  "color": "1",
  "label": "leads to"
}

| 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

{
  "color": "#FF0000"
}

Preset Colors

{
  "color": "1"
}

| 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

{
  "nodes": [
    {
      "id": "8a9b0c1d2e3f4a5b",
      "type": "text",
      "x": 0,
      "y": 0,
      "width": 300,
      "height": 150,
      "text": "# Main Idea\n\nThis is the central concept."
    },
    {
      "id": "1a2b3c4d5e6f7a8b",
      "type": "text",
      "x": 400,
      "y": -100,
      "width": 250,
      "height": 100,
      "text": "## Supporting Point A\n\nDetails here."
    },
    {
      "id": "2b3c4d5e6f7a8b9c",
      "type": "text",
      "x": 400,
      "y": 100,
      "width": 250,
      "height": 100,
      "text": "## Supporting Point B\n\nMore details."
    }
  ],
  "edges": [
    {
      "id": "3c4d5e6f7a8b9c0d",
      "fromNode": "8a9b0c1d2e3f4a5b",
      "fromSide": "right",
      "toNode": "1a2b3c4d5e6f7a8b",
      "toSide": "left"
    },
    {
      "id": "4d5e6f7a8b9c0d1e",
      "fromNode": "8a9b0c1d2e3f4a5b",
      "fromSide": "right",
      "toNode": "2b3c4d5e6f7a8b9c",
      "toSide": "left"
    }
  ]
}

Project Board with Groups

{
  "nodes": [
    {
      "id": "5e6f7a8b9c0d1e2f",
      "type": "group",
      "x": 0,
      "y": 0,
      "width": 300,
      "height": 500,
      "label": "To Do",
      "color": "1"
    },
    {
      "id": "6f7a8b9c0d1e2f3a",
      "type": "group",
      "x": 350,
      "y": 0,
      "width": 300,
      "height": 500,
      "label": "In Progress",
      "color": "3"
    },
    {
      "id": "7a8b9c0d1e2f3a4b",
      "type": "group",
      "x": 700,
      "y": 0,
      "width": 300,
      "height": 500,
      "label": "Done",
      "color": "4"
    },
    {
      "id": "8b9c0d1e2f3a4b5c",
      "type": "text",
      "x": 20,
      "y": 50,
      "width": 260,
      "height": 80,
      "text": "## Task 1\n\nImplement feature X"
    },
    {
      "id": "9c0d1e2f3a4b5c6d",
      "type": "text",
      "x": 370,
      "y": 50,
      "width": 260,
      "height": 80,
      "text": "## Task 2\n\nReview PR #123",
      "color": "2"
    },
    {
      "id": "0d1e2f3a4b5c6d7e",
      "type": "text",
      "x": 720,
      "y": 50,
      "width": 260,
      "height": 80,
      "text": "## Task 3\n\n~~Setup CI/CD~~"
    }
  ],
  "edges": []
}

Research Canvas with Files and Links

{
  "nodes": [
    {
      "id": "1e2f3a4b5c6d7e8f",
      "type": "text",
      "x": 300,
      "y": 200,
      "width": 400,
      "height": 200,
      "text": "# Research Topic\n\n## Key Questions\n\n- How does X affect Y?\n- What are the implications?",
      "color": "5"
    },
    {
      "id": "2f3a4b5c6d7e8f9a",
      "type": "file",
      "x": 0,
      "y": 0,
      "width": 250,
      "height": 150,
      "file": "Literature/Paper A.pdf"
    },
    {
      "id": "3a4b5c6d7e8f9a0b",
      "type": "file",
      "x": 0,
      "y": 200,
      "width": 250,
      "height": 150,
      "file": "Notes/Meeting Notes.md",
      "subpath": "#Key Insights"
    },
    {
      "id": "4b5c6d7e8f9a0b1c",
      "type": "link",
      "x": 0,
      "y": 400,
      "width": 250,
      "height": 100,
      "url": "https://example.com/research"
    },
    {
      "id": "5c6d7e8f9a0b1c2d",
      "type": "file",
      "x": 750,
      "y": 150,
      "width": 300,
      "height": 250,
      "file": "Attachments/diagram.png"
    }
  ],
  "edges": [
    {
      "id": "6d7e8f9a0b1c2d3e",
      "fromNode": "2f3a4b5c6d7e8f9a",
      "fromSide": "right",
      "toNode": "1e2f3a4b5c6d7e8f",
      "toSide": "left",
      "label": "supports"
    },
    {
      "id": "7e8f9a0b1c2d3e4f",
      "fromNode": "3a4b5c6d7e8f9a0b",
      "fromSide": "right",
      "toNode": "1e2f3a4b5c6d7e8f",
      "toSide": "left",
      "label": "informs"
    },
    {
      "id": "8f9a0b1c2d3e4f5a",
      "fromNode": "4b5c6d7e8f9a0b1c",
      "fromSide": "right",
      "toNode": "1e2f3a4b5c6d7e8f",
      "toSide": "left",
      "toEnd": "arrow",
      "color": "6"
    },
    {
      "id": "9a0b1c2d3e4f5a6b",
      "fromNode": "1e2f3a4b5c6d7e8f",
      "fromSide": "right",
      "toNode": "5c6d7e8f9a0b1c2d",
      "toSide": "left",
      "label": "visualized by"
    }
  ]
}

Flowchart

{
  "nodes": [
    {
      "id": "a0b1c2d3e4f5a6b7",
      "type": "text",
      "x": 200,
      "y": 0,
      "width": 150,
      "height": 60,
      "text": "**Start**",
      "color": "4"
    },
    {
      "id": "b1c2d3e4f5a6b7c8",
      "type": "text",
      "x": 200,
      "y": 100,
      "width": 150,
      "height": 60,
      "text": "Step 1:\nGather data"
    },
    {
      "id": "c2d3e4f5a6b7c8d9",
      "type": "text",
      "x": 200,
      "y": 200,
      "width": 150,
      "height": 80,
      "text": "**Decision**\n\nIs data valid?",
      "color": "3"
    },
    {
      "id": "d3e4f5a6b7c8d9e0",
      "type": "text",
      "x": 400,
      "y": 200,
      "width": 150,
      "height": 60,
      "text": "Process data"
    },
    {
      "id": "e4f5a6b7c8d9e0f1",
      "type": "text",
      "x": 0,
      "y": 200,
      "width": 150,
      "height": 60,
      "text": "Request new data",
      "color": "1"
    },
    {
      "id": "f5a6b7c8d9e0f1a2",
      "type": "text",
      "x": 400,
      "y": 320,
      "width": 150,
      "height": 60,
      "text": "**End**",
      "color": "4"
    }
  ],
  "edges": [
    {
      "id": "a6b7c8d9e0f1a2b3",
      "fromNode": "a0b1c2d3e4f5a6b7",
      "fromSide": "bottom",
      "toNode": "b1c2d3e4f5a6b7c8",
      "toSide": "top"
    },
    {
      "id": "b7c8d9e0f1a2b3c4",
      "fromNode": "b1c2d3e4f5a6b7c8",
      "fromSide": "bottom",
      "toNode": "c2d3e4f5a6b7c8d9",
      "toSide": "top"
    },
    {
      "id": "c8d9e0f1a2b3c4d5",
      "fromNode": "c2d3e4f5a6b7c8d9",
      "fromSide": "right",
      "toNode": "d3e4f5a6b7c8d9e0",
      "toSide": "left",
      "label": "Yes",
      "color": "4"
    },
    {
      "id": "d9e0f1a2b3c4d5e6",
      "fromNode": "c2d3e4f5a6b7c8d9",
      "fromSide": "left",
      "toNode": "e4f5a6b7c8d9e0f1",
      "toSide": "right",
      "label": "No",
      "color": "1"
    },
    {
      "id": "e0f1a2b3c4d5e6f7",
      "fromNode": "e4f5a6b7c8d9e0f1",
      "fromSide": "top",
      "fromEnd": "none",
      "toNode": "b1c2d3e4f5a6b7c8",
      "toSide": "left",
      "toEnd": "arrow"
    },
    {
      "id": "f1a2b3c4d5e6f7a8",
      "fromNode": "d3e4f5a6b7c8d9e0",
      "fromSide": "bottom",
      "toNode": "f5a6b7c8d9e0f1a2",
      "toSide": "top"
    }
  ]
}

ID Generation

Node and edge IDs must be unique strings. Obsidian generates 16-character hexadecimal IDs:

"id": "6f0ad84f44ce9c17"
"id": "a3b2c1d0e9f8g7h6"
"id": "1234567890abcdef"

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

  • All id values must be unique across nodes and edges
  • fromNode and toNode must reference existing node IDs
  • Required fields must be present for each node type
  • type must be one of: text, file, link, group
  • backgroundStyle must be one of: cover, ratio, repeat
  • fromSide, toSide must be one of: top, right, bottom, left
  • fromEnd, toEnd must be one of: none, arrow
  • Color presets must be "1" through "6" or valid hex color

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How to use it

Copy the folder

Take anbeime/json-canvas from the repository into ~/.claude/skills for personal use, or into .claude/skills inside a project.

Check the name does not clash

The agent identifies a skill by the name field in its header. Two skills with the same name cannot sit side by side — one of them will be ignored.