PopUI MCP server

PopUI is a companion desktop app for macOS that enhances Claude Desktop with collaborative user interface capabilities. It creates a bi-directional bridge between Claude and visual interfaces, allowing Claude to create and display UIs, read user changes, update the interface visually, and receive events and text back without keyboard input.

Installation

Simply download the latest release of PopUI and launch the application.

Setting Up with Claude Desktop

When you first launch PopUI, you'll be prompted to install it into Claude Desktop. After installation:

1. PopUI will automatically launch when you open Claude Desktop
2. It will connect as an MCP (Model Context Protocol) server
3. All user interfaces created during your conversations will be accessible through:
   • The settings window
   • The menubar icon

Using PopUI

PopUI enables several powerful interaction modes with Claude Desktop:

Collaborative UI Experiences

Unlike standard Claude Artifacts, PopUI creates a complete interaction loop where:

• Claude can generate interactive UI elements
• Claude can monitor changes made in the UI
• Claude can update the UI in response to conversation
• The UI can send events and text back to the chat conversation

Visual Context Capabilities

PopUI enables shared visual contexts between you and Claude, allowing for:

• Control panels for tweaking values during conversations
• Color pickers with swatches for visual design discussions
• Physical layout visualization and manipulation
• Turn-based games on a shared gameboard
• Real-time elements like clocks
• Expressive interfaces for emotional context

Accessing Created Interfaces

You can view and interact with all interfaces created during your conversations through:

• The PopUI settings window
• The PopUI menubar icon in macOS

The interface panel allows you to manage and switch between different visual contexts created during your conversations with Claude.

Technical Details

PopUI functions as an MCP gateway for Claude Desktop, providing all necessary dependencies automatically. Once installed, it creates a seamless connection between Claude's reasoning capabilities and interactive visual elements.

How to install this MCP server

For Claude Code

To add this MCP server to Claude Code, run this command in your terminal:

claude mcp add-json "popui" '{"command":"open","args":["-a","PopUI"]}'

See the official Claude Code MCP documentation for more details.

For Cursor

There are two ways to add an MCP server to Cursor. The most common way is to add the server globally in the ~/.cursor/mcp.json file so that it is available in all of your projects.

If you only need the server in a single project, you can add it to the project instead by creating or adding it to the .cursor/mcp.json file.

Adding an MCP server to Cursor globally

To add a global MCP server go to Cursor Settings > Tools & Integrations and click "New MCP Server".

When you click that button the ~/.cursor/mcp.json file will be opened and you can add your server like this:

{
    "mcpServers": {
        "popui": {
            "command": "open",
            "args": [
                "-a",
                "PopUI"
            ]
        }
    }
}

Adding an MCP server to a project

To add an MCP server to a project you can create a new .cursor/mcp.json file or add it to the existing one. This will look exactly the same as the global MCP server example above.

How to use the MCP server

Once the server is installed, you might need to head back to Settings > MCP and click the refresh button.

The Cursor agent will then be able to see the available tools the added MCP server has available and will call them when it needs to.

You can also explicitly ask the agent to use the tool by mentioning the tool name and describing what the function does.

For Claude Desktop

To add this MCP server to Claude Desktop:

1. Find your configuration file:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json
• Linux: ~/.config/Claude/claude_desktop_config.json

2. Add this to your configuration file:

{
    "mcpServers": {
        "popui": {
            "command": "open",
            "args": [
                "-a",
                "PopUI"
            ]
        }
    }
}

3. Restart Claude Desktop for the changes to take effect