Rubus for AI assistants

Let ChatGPT, Claude or Copilot draw clean business charts with Rubus. You connect once; then you ask for a chart in plain words and get it back as a picture and a file for PowerPoint.

1. Copy the Rubus address

https://rubus-mcp.ekuljanov.workers.dev/mcp

No account and no key: the address is all an assistant needs.

2. Add it to your assistant

Pick yours. Menu names change now and then; look for “connectors”, “tools” or “MCP”.

Claude (claude.ai, Claude Desktop)

Open Settings → Connectors and choose Add custom connector.
Name it Rubus, paste the address, and choose Add.
In a chat, open the tools menu (the + or the sliders button) and make sure Rubus is on.

Custom connectors need a paid Claude plan. On Team and Enterprise plans an owner adds them for everyone. Claude in Excel and PowerPoint uses the same connectors where your plan allows it.

ChatGPT

Open Settings → Apps & Connectors → Advanced settings and turn on Developer mode.
Back in Apps & Connectors, choose Create. Name it Rubus, paste the address, set authentication to No authentication, tick that you trust it, and choose Create.
In a chat, choose + → Developer mode and add Rubus.

Needs a plan with developer mode (Plus, Pro, Business, Enterprise or Edu).

Microsoft Copilot (Copilot Studio)

Open your agent in Copilot Studio and go to Tools → Add a tool → New tool.
Choose Model Context Protocol, name it Rubus, paste the address, and set authentication to None.
Create it, add it to the agent, and publish the agent to Microsoft 365 Copilot or Teams.

GitHub Copilot in VS Code

Add this to .vscode/mcp.json in your project (or run MCP: Add Server and choose HTTP):

{
  "servers": {
    "rubus": { "type": "http", "url": "https://rubus-mcp.ekuljanov.workers.dev/mcp" }
  }
}

Claude Code

claude mcp add --transport http rubus https://rubus-mcp.ekuljanov.workers.dev/mcp

Cursor and other MCP apps

Add a server with this address. In Cursor, ~/.cursor/mcp.json:

{
  "mcpServers": {
    "rubus": { "url": "https://rubus-mcp.ekuljanov.workers.dev/mcp" }
  }
}

3. Ask for a chart

Say what you want in plain words, with the numbers or a table. Mention Rubus the first time so the assistant uses it. For example:

“With Rubus, draw a stacked column chart of revenue by product line, 2022–2025: Products 24, 27, 31, 33; Services 12, 15, 19, 26. EUR m. Title: Services grew twice as fast.”
“Turn this table into a Rubus waterfall from 2024 EBIT to 2025 EBIT.” (and paste the table)
“Make it a bar chart, largest first, and highlight Germany.”

Rubus draws: stacked, 100% and clustered columns and bars, column + line, two axes, line, actual vs plan, indexed line, waterfall (upright or sideways), Mekko, scatter, bubble, quadrant and before → after.

4. Put it on a slide

The assistant shows the chart and gives you a link. Open it.
Choose Download SVG. In PowerPoint: Insert → Pictures → This Device, and pick the file. An SVG stays sharp at any size; right-click → Convert to Shape to recolour a part.
To keep editing in the Rubus add-in, choose Copy for Rubus on the chart page and paste into the table in the Rubus pane.

In Claude for Excel and PowerPoint

Claude's Excel and PowerPoint add-ins use the same connectors, so Rubus works there too. To get a chart you can keep editing, have both add-ins open: Claude and Rubus.

Ask Claude as above. Claude writes a small Rubus block: into cells in Excel, or into a text box on the slide in PowerPoint.
Click the block (in PowerPoint, select the text box). The Rubus pane says Found a Rubus chart block.
Press Draw this chart, check it, and press Insert. In PowerPoint the chart takes the text box's place.

Good to know

A chart and its numbers are kept for 30 days so its link works. Anyone with the link can open it; links are random and not listed anywhere. Send only numbers you would put in a shared link.
No sign-in, no tracking, nothing else stored.
If the numbers don’t fit (four values for three years), Rubus says what to fix and the assistant tries again.