canvas

name	canvas
description	Present, navigate, snapshot, and hide HTML content on connected OpenClaw nodes (Mac, iOS, Android) via the canvas tool. Use when displaying games, visualizations, dashboards, or interactive demos on remote node canvas views, or when debugging canvas URL routing across loopback, LAN, and Tailscale bind modes.

Canvas

Display HTML content on connected OpenClaw nodes via the canvas host server (port 18793) and node bridge (port 18790).

Workflow

1. Place HTML files in the configured canvas root directory. ~/clawd/canvas/ is a common default, but verify the actual canvasHost.root on the target host before assuming it.
2. Verify the canvas host is running on the target host:

   lsof -i :18793
   

3. Check gateway bind mode and construct the canvas URL:

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

   • loopback: http://127.0.0.1:18793/__openclaw__/canvas/<file>.html
   • lan/tailnet/auto: http://<hostname>:18793/__openclaw__/canvas/<file>.html
4. Find connected nodes with canvas capability:

   openclaw nodes list
   

5. Present content on a node:

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

6. Verify content loaded. If the canvas shows a white screen, check that the URL hostname matches the bind mode and the actual host surface you are targeting; do not assume localhost or a Unix-style path layout on every machine.

Actions

Action	Description
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 ~/.openclaw/openclaw.json, enable canvasHost with a root directory and optional liveReload (auto-refreshes connected canvases on file change). The gateway.bind setting (loopback, lan, tailnet, auto) controls which interface the server binds to and which hostname nodes receive.

Treat the path and shell commands in this doc as OpenClaw-oriented examples, not a universal host contract.

Debugging

See references/canvas-debugging.md for common issues: white screen (URL mismatch), "node required" errors, "node not connected", and live reload failures.

Guardrails

• Keep HTML self-contained (inline CSS/JS) for best cross-node results.
• Use local or trusted tools only; avoid untrusted install pipelines.
• Do not paste secrets/tokens into chat output.