Clawdis Canvas

Use Canvas to render HTML/JS or A2UI surfaces and capture snapshots.

Core commands

• Present: clawdis canvas present [--node <id>] [--target <path>]
• Hide: clawdis canvas hide
• Eval JS: clawdis canvas eval --js "..."
• Snapshot: clawdis canvas snapshot

A2UI

• Push JSONL: clawdis canvas a2ui push --jsonl /path/to/file.jsonl
• Reset: clawdis canvas a2ui reset

Notes

• Keep HTML under ~/clawd/canvas when targeting remote nodes.
• Use snapshot after renders to verify UI state.
• Treat A2UI as gateway-hosted at http(s)://<gateway-host>:18789/__clawdis__/a2ui/.
• Rely on canvas a2ui push/reset to auto-navigate the Canvas to the gateway-hosted A2UI page.
• Expect A2UI to fail if the Gateway does not advertise canvasHostUrl or is unreachable:
  • A2UI_HOST_NOT_CONFIGURED
  • A2UI_HOST_UNAVAILABLE

A2UI quick flow

1. Ensure the Gateway is running and reachable from the node.
2. Build JSONL with v0.8 server→client messages (beginRendering, surfaceUpdate, dataModelUpdate, deleteSurface).
   • Do not use v0.9 createSurface (unsupported).
3. Push JSONL and (optionally) snapshot the result.

Example JSONL (v0.8)

cat > /tmp/a2ui-v0.8.jsonl <<'EOF'
{"surfaceUpdate":{"surfaceId":"main","components":[{"id":"root","component":{"Column":{"children":{"explicitList":["title","content"]}}}},{"id":"title","component":{"Text":{"text":{"literalString":"A2UI (v0.8)"},"usageHint":"h1"}}},{"id":"content","component":{"Text":{"text":{"literalString":"If you can read this, A2UI is live."},"usageHint":"body"}}}]}}
{"beginRendering":{"surfaceId":"main","root":"root"}}
EOF

clawdis canvas a2ui push --jsonl /tmp/a2ui-v0.8.jsonl --node <id>

Action callbacks (A2UI → agent)

• A2UI user actions (buttons, etc.) are bridged from the WebView back to the node via clawdisCanvasA2UIAction.
• Handle them on the agent side as CANVAS_A2UI messages (node → gateway → agent).