Json Canvas

What the source does

• FilesystemNone observedNo reads or writes in the source
• NetworkNone observedNo outbound calls in the source
• ShellNone observedNo commands run in the source
• DependenciesPinnedNothing floats
• SecretsNone foundNo keys in source

Five audit layers

Gates applied: no behavioural pass.

skills/brainstorming/scripts/node_modules/.bin/mime

skills/supabase-postgres-best-practices/CLAUDE.md

Audit 0.4.1 · source sha a5d8e1eb3451 · 21 Oct 2026Report an issue or request a re-scan

• Publisherguanyang GitHub userOwner of the repository this skill is read from
• Source folderguanyang/antigravity-skills/skills/json-canvasThe exact folder we audited
• LicenceMITAs the repository states it
• Commit pinned for this verdicta5d8e1eb3451A new audit runs when the source changes
• Repository statusNot archivedPushed today
• Sandboxed runNot runSkills are read, not executed; layer L4 is skipped

Its description: 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…

---
name: json-canvas
description: 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.
---

# JSON Canvas Skill

## File Structure

A canvas file (`.canvas`) contains two top-level arrays following the [JSON Canvas Spec 1.0](https://jsoncanvas.org/spec/1.0/):

```json
{
  "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

| Attribute | Required | Type | Description |
|-----------|----------|------|-------------|
| `id` | Yes | string | Unique 16-char hex identifier |
| `type` | Yes | string | `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 | Preset `"1"`-`"6"` or hex (e.g., `"#FF0000"`) |

### Text Nodes

| Attribute | Required | Type | Description |
|-----------|----------|------|-------------|
| `text` | Yes | string | Plain text with Markdown syntax |

```json
{
  "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 |
|-----------|----------|------|-------------|
| `file` | Yes | string | Path to file within the system |
| `subpath` | No | string | Link to heading or block (starts with `#`) |

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

### Link Nodes

| Attribute | Required | Type | Description |
|-----------|----------|------|-------------|
| `url` | Yes | string | External URL |

```json
{
  "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 |
|-----------|----------|------|-------------|
| `label` | No | string | Text label for the group |
| `background` | No | string | Path to background image |
| `backgroundStyle` | No | string | `cover`, `ratio`, or `repeat` |

```json
{
  "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 |
|-----------|----------|------|---------|-------------|
| `id` | Yes | string | - | Unique identifier |
| `fromNode` | Yes | string | - | Source node ID |
| `fromSide` | No | string | - | `top`, `right`, `bottom`, or `left` |
| `fromEnd` | No | string | `none` | `none` or `arrow` |
| `toNode` | Yes | string | - | Target node ID |
| `toSide` | No | string | - | `top`, `right`, `bottom`, or `left` |
| `toEnd` | No | string | `arrow` | `none` or `arrow` |
| `color` | No | canvasColor | - | Line color |
| `label` | No | string | - | Text label |

```json
{
  "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"
```

## Lay

Excerpt, first 6,000 characters of SKILL.md, verbatim from the audited commit. It is text from someone else’s repository, quoted so you can judge it before your agent reads it.

git clone https://github.com/guanyang/antigravity-skills
git -C antigravity-skills checkout a5d8e1eb3451

Works in

1. 2026-10-21
   ✓SAFE B 89 / 100

   first audit · source a5d8e1eb3451

Questions about Json Canvas

• github.com/guanyang/antigravity-skills/tree/main/skills/json-can — the audited source at commit a5d8e1eb3451 and every finding aboveObserved · 21 Oct 2026

Spotted something wrong? Report a correction · Methodology