Connect your AI

dia connects to AI assistants through MCP. Once you register the connection URL with your AI, it can create diagrams in dia.

Connection URL

https://dia.rakudeji.com/mcp

The same URL and steps are shown under AI integration (AI 連携) in the dia sidebar. While you have no documents yet, they also appear on the Home (ホーム) screen.

Register dia with your AI

In Claude, open Settings, then Connectors.
Choose Add custom connector, enter dia as the name, paste the connection URL, and add it.
Connect the dia connector you added.
When the dia page opens, review it and choose Allow (許可する).

Run this command in your terminal:

claude mcp add --transport http dia https://dia.rakudeji.com/mcp

In Claude Code, open /mcp, select dia, and authenticate.
When the dia page opens, review it and choose Allow (許可する).

Add the following to Cursor’s config file, ~/.cursor/mcp.json:

{
  "mcpServers": {
    "dia": {
      "url": "https://dia.rakudeji.com/mcp"
    }
  }
}

In Cursor’s MCP settings, sign in to dia.
When the dia page opens, review it and choose Allow (許可する).

In your MCP-capable AI’s settings, register the connection URL as a remote MCP server (HTTP).
When the dia page opens, review it and choose Allow (許可する).

dia authenticates connections with OAuth, so your AI must support authentication for remote MCP servers.

Allow access

The first time your AI connects, a dia page opens in your browser.

If you’re not signed in to dia, sign in with Sign in with Google (Google でログイン).
The Allow access (アクセスの許可) page says that the app is requesting access to dia. Check the signed-in email address and the permissions listed.
Choose Allow (許可する). If you don’t recognize the request, choose Cancel (キャンセル).

Once allowed, the AI can:

Create, edit, and view diagrams
Keep working without signing in again

Check that it works

Ask your AI something like:

Create a service architecture diagram in dia with Web, API, and PostgreSQL.

When the AI creates a document, it appears on the Home (ホーム) screen. If you have no documents yet, Home shows a message that dia is waiting for your AI to connect, and it opens the first document automatically once the AI creates it.

The connected AI is listed under Connected apps (接続中のアプリ) on the AI integration (AI 連携) page, along with when it was connected and last used.

Disconnect an AI

To stop an AI from using dia, disconnect it.

Open AI integration (AI 連携) from the sidebar. You can also open Settings (設定) from the account menu and then AI integration (AI 連携).
Under Connected apps (接続中のアプリ), choose Disconnect (接続を解除) next to the app.
Confirm by choosing Disconnect (接続を解除).

A disconnected AI can no longer use dia. To use it again, reconnect and allow access.