JSON Canvas Skill

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