pi-canvas

Use your phone or tablet as a drawing/photo input for Pi.

Run /canvas in any Pi session, open the Pi Canvas page on your iPhone or iPad over Tailscale, draw something or pick a photo, hit send, and it shows up in your Pi conversation — image and all.

| iPhone canvas | Pi receives the drawing | |---|---| | | |

Install

pi install https://github.com/swairshah/pi-canvas

Or from a local checkout:

cd pi-canvas
pi install .

Setup

Your Mac and phone/tablet need to be on the same Tailscale network.

1. Start a Pi session (the extension loads automatically).

2. Run /canvas status — it prints your Canvas URL, something like:

   http://100.119.70.61:18120/

3. Open that URL on your iPhone/iPad in Safari.

4. Save it to your Home Screen — now you have a one-tap shortcut.

That's it. The URL stays the same across Pi sessions.

Usage

In Pi, run:

/canvas

Then open the Pi Canvas shortcut on your phone. You'll see the pending request — tap Open, draw or pick a photo, and tap send.

The drawing is delivered directly into your Pi conversation as an inline image with the local file path, so the model can see and reason about it.

Modes

/canvas                            let the device choose (draw / photo / annotate)
/canvas draw                       open a blank drawing canvas
/canvas photo                      pick or capture a photo
/canvas annotate                   pick a photo, then draw on top of it
/canvas draw sketch the layout     include a prompt shown on the device

Other commands

/canvas status     show the Home Screen URL and broker info
/canvas open       open the canvas page locally on your Mac

How it works

• The extension starts a small HTTP server on your Mac (port 18120, bound to 0.0.0.0).
• /canvas creates a pending request tied to your current Pi session.
• Any device on your Tailscale network can open the page, claim the request, and submit.
• Submitted images are saved locally under ~/.pi/agent/pi-canvas-media/.
• The image is injected back into the requesting Pi session as a user message with both the image attachment and the file path.
• No tokens, no cloud, no accounts. Just Tailscale.

Input modes

Draw — freehand canvas with colors (black, red, green, blue, white/eraser), brush sizes (S/M/L), undo, and clear. Works great with finger or Apple Pencil.

Photo — pick from your photo library or take a picture with the camera.

Annotate — pick a photo first, then draw annotations on top of it before submitting.

All modes include an optional note field you can type into before sending.

Config (optional)

PI_CANVAS_PORT=18120              # default port
PI_CANVAS_BIND=0.0.0.0            # default; use 127.0.0.1 for Mac-only
PI_CANVAS_TOKEN=mysecret          # optional token auth (off by default)
PI_CANVAS_PUBLIC_URL=http://...   # override the URL shown by /canvas status

License

MIT