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claude-code

Kabot canvas

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

Canvas Skill

Display HTML content on connected Kabot nodes (Mac app, iOS, Android).

Overview

The canvas tool lets you present web content on any connected node's canvas view. Great for:

  • Displaying games, visualizations, dashboards
  • Showing generated HTML content
  • Interactive demos

How It Works

Architecture

┌─────────────────┐     ┌──────────────────┐     ┌─────────────┐
│  Canvas Host    │────▶│   Node Bridge    │────▶│  Node App   │
│  (HTTP Server)  │     │  (TCP Server)    │     │ (Mac/iOS/   │
│  Port 18793     │     │  Port 18790      │     │  Android)   │
└─────────────────┘     └──────────────────┘     └─────────────┘
  1. Canvas Host Server: Serves static HTML/CSS/JS files from 
    canvasHost.root
    directory
  2. Node Bridge: Communicates canvas URLs to connected nodes
  3. Node Apps: Render the content in a WebView

Tailscale Integration

The canvas host server binds based on 

gateway.bind
setting:

Bind ModeServer Binds ToCanvas URL Uses
loopback
127.0.0.1localhost (local only)
lan
LAN interfaceLAN IP address
tailnet
Tailscale interfaceTailscale hostname
auto
Best availableTailscale > LAN > loopback

Key insight: The 

canvasHostHostForBridge
is derived from 
bridgeHost
. When bound to Tailscale, nodes receive URLs like:

http://<tailscale-hostname>:18793/__kabot__/canvas/<file>.html

This is why localhost URLs don't work - the node receives the Tailscale hostname from the bridge!

Actions

ActionDescription
present
Show canvas with optional target URL
hide
Hide the canvas
navigate
Navigate to a new URL
eval
Execute JavaScript in the canvas
snapshot
Capture screenshot of canvas

Configuration

In 

~/.kabot/kabot.json
:

{
  "canvasHost": {
    "enabled": true,
    "port": 18793,
    "root": "/Users/you/clawd/canvas",
    "liveReload": true
  },
  "gateway": {
    "bind": "auto"
  }
}

Live Reload

When 

liveReload: true
(default), the canvas host:

  • Watches the root directory for changes (via chokidar)
  • Injects a WebSocket client into HTML files
  • Automatically reloads connected canvases when files change

Great for development!

Workflow

1. Create HTML content

Place files in the canvas root directory (default 

~/clawd/canvas/
):

cat > ~/clawd/canvas/my-game.html << 'HTML'
<!DOCTYPE html>
<html>
<head><title>My Game</title></head>
<body>
  <h1>Hello Canvas!</h1>
</body>
</html>
HTML

2. Find your canvas host URL

Check how your gateway is bound:

cat ~/.kabot/kabot.json | jq '.gateway.bind'

Then construct the URL:

  • loopback: 
    http://127.0.0.1:18793/__kabot__/canvas/<file>.html
  • lan/tailnet/auto: 
    http://<hostname>:18793/__kabot__/canvas/<file>.html

Find your Tailscale hostname:

tailscale status --json | jq -r '.Self.DNSName' | sed 's/\.$//'

3. Find connected nodes

kabot nodes list

Look for Mac/iOS/Android nodes with canvas capability.

4. Present content

canvas action:present node:<node-id> target:<full-url>

Example:

canvas action:present node:mac-63599bc4-b54d-4392-9048-b97abd58343a target:http://peters-mac-studio-1.sheep-coho.ts.net:18793/__kabot__/canvas/snake.html

5. Navigate, snapshot, or hide

canvas action:navigate node:<node-id> url:<new-url>
canvas action:snapshot node:<node-id>
canvas action:hide node:<node-id>

Debugging

White screen / content not loading

Cause: URL mismatch between server bind and node expectation.

Debug steps:

  1. Check server bind: 
    cat ~/.kabot/kabot.json | jq '.gateway.bind'
  2. Check what port canvas is on: 
    lsof -i :18793
  3. Test URL directly: 
    curl http://<hostname>:18793/__kabot__/canvas/<file>.html

Solution: Use the full hostname matching your bind mode, not localhost.

"node required" error

Always specify 

node:<node-id>
parameter.

"node not connected" error

Node is offline. Use 

kabot nodes list
to find online nodes.

Content not updating

If live reload isn't working:

  1. Check 
    liveReload: true
    in config
  2. Ensure file is in the canvas root directory
  3. Check for watcher errors in logs

URL Path Structure

The canvas host serves from 

/__kabot__/canvas/
prefix:

http://<host>:18793/__kabot__/canvas/index.html  → ~/clawd/canvas/index.html
http://<host>:18793/__kabot__/canvas/games/snake.html → ~/clawd/canvas/games/snake.html

The 

/__kabot__/canvas/
prefix is defined by 
CANVAS_HOST_PATH
constant.

Tips

  • Keep HTML self-contained (inline CSS/JS) for best results
  • Use the default index.html as a test page (has bridge diagnostics)
  • The canvas persists until you 
    hide
    it or navigate away
  • Live reload makes development fast - just save and it updates!
  • A2UI JSON push is WIP - use HTML files for now