Talk with Claude on a Whiteboard! (GRWB, powered by Excalidraw)

Why?

Come on, meetings belong on a whiteboard, right? I want to talk with Claude in pictures, too.

What did I do?

I made a Claude Code plugin called gr-whiteboard (GRWB for short).

• A human writes on the whiteboard. Claude Code reads it and answers on the same board.
• The whiteboard server runs on your local PC.
• An iPad or other PCs on the same network can join.
• Powered by Excalidraw
• Apache-2.0. It is an alpha now (0.7.3).

What it can do

• Discuss on the board. Write something and send it with the paper plane button (or Ctrl+Shift+Enter). Claude answers right below your text, in blue. Like a chat on your phone.
• Draw the diagrams of your spec as they are. The whiteboard server draws the Mermaid of your .md (flowchart, sequence, class, state, ER, and pie: 6 kinds) without any editing. Just ask, like "show the state machine of 3.4.1 of the spec".
• Tables, too. Claude can also edit, delete, and undo what it drew.
• Join from your iPad. Just scan a QR code. Trust the private certificate authority once, and Safari's "Not secure" goes away, too.
• The functions are in the palette on the right of the screen. Send (the paper plane) is there, and you can more or less see what Claude is doing.
• Stops by itself. If nobody touches it for one hour, it saves the board as an .excalidraw file and stops. It warns you five minutes before.

The screen? Well, it looks like this ♪

How?

Getting started

Just say this to Claude Code (or the Code tab of Claude Desktop):

Make https://github.com/GoodRelax/gr-whiteboard usable.

If you don't have Node.js or Git, Claude installs them with winget.
If it asks for permission, check it carefully, and say yes at your own risk.
If you are worried, ask Claude what it is.

When the install is done, restart Claude.

Open the whiteboard

A command like this brings up the board in your browser (it should).
Then just write text and press the paper plane button.
On a fresh Windows PC, this takes about 15 minutes.

To end, say "stop" in the chat. The board is saved and comes back next time you open it.

Want to use it on your iPad?

Tell Claude "I want to use the whiteboard on my iPad".
After your OK, the palette shows Join (a QR code). Scan it with the iPad to join.
There is only a private CA (certificate authority), so it's a bit of a hassle, but Claude should tell you how if you ask.
If I ever get a sponsor, I'll improve this part... lol

How does it work?

The spec and the code are all public. So ask Claude Code:

Explain the spec of https://github.com/GoodRelax/gr-whiteboard

It should explain it at your tech level.

Please note

• It is an alpha. I use it every day, but it is brand new. A lot may change before 1.0.
• It needs internet access. The page loads Excalidraw, React, and Mermaid from esm.sh.
• The board link is a key. It has a token after #t=. Anyone with the link can see and change the board, and talk to Claude.
• Tested only on Windows 11 with Edge, and on iPad and iPhone with Safari. Others? No idea.

GRWB is an unofficial tool that kindly gets to use Excalidraw.
With GRWB, you can discuss within your LAN at most.
With the real excalidraw.com, you can have serious whiteboard discussions with engineers all over the world. A truly godlike tool ♪

Fun fact: I built the second half of it by discussing on GRWB

A little meta story.
I worked out the spec and the code of this plugin while talking with Claude Code on the whiteboard (lol)

I did test it on a clean PC in Hyper-V, but it may not work well in a different environment.
If that happens, just say "Whatever, just make it work!" as usual, and it will surely do it. If you're reading this, your Claude can!

Is it worth it?

Of course! Just try it, and you'll see ♪

I released it as an alpha because I want your feedback to decide the next move.
"This feels wrong", "I want this": please write them in GitHub Issues. I'll look when I have time.

But I think quite a few people will find this useful, right? ...Ever heard "Stop the air battle. Keep the minutes."?
Well, someone somewhere in the world is probably already doing the same thing (lol)

© 2026 GoodRelax. Apache-2.0 License.

Comments

[Oleksandr]

The 'I want to talk with Claude in pictures, too' is the most relatable reason to build this. Meetings belong on a whiteboard, and so does AI collaboration. The fact that you built the second half of it on the whiteboard is a great meta-story.