About
-----

**drawio-desktop-mcp** is a fork of [drawio-desktop](https://github.com/jgraph/drawio-desktop) with a built-in [MCP (Model Context Protocol)](https://modelcontextprotocol.io/) server that lets AI agents create and edit diagrams directly in the running desktop app.

**drawio-desktop** is a diagramming desktop app based on [Electron](https://electronjs.org/) that wraps the [core draw.io editor](https://github.com/jgraph/drawio).

MCP Server
----------

The app includes an embedded MCP server on `http://127.0.0.1:9100/mcp` (Streamable HTTP transport) that starts automatically. Multiple AI agents can connect simultaneously and manipulate diagrams in real time.

### Quick Start

```bash
# Clone (recursive for submodule)
git clone --recursive https://github.com/ArdaUzun/drawio-desktop-mcp.git
cd drawio-desktop-mcp

# Install and run
pnpm install
pnpm start
```

The MCP server starts automatically on port 9100.

### Connect Claude Code

```bash
claude mcp add drawio-desktop --transport http http://127.0.0.1:9100/mcp --scope user
```

Or add a `.mcp.json` to your project:

```json
{
  "mcpServers": {
    "drawio-desktop": {
      "type": "http",
      "url": "http://127.0.0.1:9100/mcp"
    }
  }
}
```

### Available Tools (20)

| Category | Tools |
|----------|-------|
| **Inspect** | `get-diagram-info`, `get-diagram-screenshot`, `get-selected-cell`, `list-paged-model` |
| **Shapes** | `add-rectangle`, `add-cell-of-shape`, `edit-cell`, `delete-cell-by-id` |
| **Edges** | `add-edge`, `edit-edge` |
| **Shape Library** | `get-shape-categories`, `get-shapes-in-category`, `get-shape-by-name`, `set-cell-shape` |
| **Layers** | `list-layers`, `get-active-layer`, `set-active-layer`, `create-layer`, `move-cell-to-layer` |
| **Data** | `set-cell-data` |

### Health Check

```bash
curl http://127.0.0.1:9100/health
# {"status":"ok","tools":20,"windows":1,"pending":0}
```

### Flatpak Install

```bash
# Build unpacked electron app
pnpm run build:dir
pnpm run build:flatpak-prep

# Build and install Flatpak (requires flatpak-builder + org.electronjs.Electron2.BaseApp//24.08)
flatpak-builder --user --install --force-clean build-flatpak flatpak/com.jgraph.drawio.desktop.yml
flatpak run com.jgraph.drawio.desktop//master
```

### Configuration

| Setting | CLI Flag | Env Var | Default |
|---------|----------|---------|---------|
| MCP Port | `--mcp-port <n>` | `DRAWIO_MCP_PORT` | `9100` |

### Updating from Upstream

```bash
git fetch upstream
git merge upstream/dev
git push origin dev
```

Download built binaries from the [releases section](https://github.com/jgraph/drawio-desktop/releases).

**Can I use this app for free?** Yes, under the apache 2.0 license. If you don't change the code and accept it is provided "as-is", you can use it for any purpose.

Security
--------

draw.io Desktop is designed to be completely isolated from the Internet, apart from the update process. This checks github.com at startup for a newer version and downloads it from an AWS S3 bucket owned by Github. All JavaScript files are self-contained, the Content Security Policy forbids running remotely loaded JavaScript.

No diagram data is ever sent externally, nor do we send any analytics about app usage externally. There is a Content Security Policy in place on the web part of the interface to ensure external transmission cannot happen, even by accident.

Security and isolating the app are the primarily objectives of draw.io desktop. If you ask for anything that involves external connections enabled in the app by default, the answer will be no.

Support
-------

Support is provided on a reasonable business constraints basis, but without anything contractually binding. All support is provided via this repo. There is no private ticketing support for non-paying users.

Purchasing draw.io for Confluence or Jira does not entitle you to commercial support for draw.io desktop.

Developing
----------

**draw.io** is a git submodule of **drawio-desktop**. To get both you need to clone recursively:

`git clone --recursive https://github.com/jgraph/drawio-desktop.git`

To run this:
1. `npm install` (in the root directory of this repo)
2. [internal use only] export DRAWIO_ENV=dev if you want to develop/debug in dev mode.
3. `npm start` _in the root directory of this repo_ runs the app. For debugging, use `npm start --enable-logging`.

Note: If a symlink is used to refer to drawio repo (instead of the submodule), then symlink the `node_modules` directory inside `drawio/src/main/webapp` also.

To release:
1. Update the draw.io sub-module and push the change. Add version tag before pushing to origin.
2. Wait for the builds to complete (https://travis-ci.org/jgraph/drawio-desktop and https://ci.appveyor.com/project/davidjgraph/drawio-desktop)
3. Go to https://github.com/jgraph/drawio-desktop/releases, edit the preview release.
4. Download the windows exe and windows portable, sign them using `signtool sign /a /tr http://rfc3161timestamp.globalsign.com/advanced /td SHA256 c:/path/to/your/file.exe`
5. Re-upload signed file as `draw.io-windows-installer-x.y.z.exe` and `draw.io-windows-no-installer-x.y.z.exe`
6. Add release notes
7. Publish release

*Note*: In Windows release, when using both x64 and is32 as arch, the result is one big file with both archs. This is why we split them.

Local Storage and Session Storage is stored in the AppData folder:

- macOS: `~/Library/Application Support/draw.io`
- Windows: `C:\Users\<USER-NAME>\AppData\Roaming\draw.io\`

Not open-contribution
---------------------

draw.io is closed to contributions (unless a maintainer permits it, which is extremely rare).

The level of complexity of this project means that even simple changes 
can break a _lot_ of other moving parts. The amount of testing required 
is far more than it first seems. If we were to receive a PR, we'd have 
to basically throw it away and write it how we want it to be implemented.

We are grateful for community involvement, bug reports, & feature requests. We do
not wish to come off as anything but welcoming, however, we've
made the decision to keep this project closed to contributions for 
the long term viability of the project.