Companion

Companion is a utility for testing and debugging your MCP servers on macOS, iOS, and visionOS. It's built using the official Swift SDK.

[!IMPORTANT]
Companion is in early development and is still missing some important features, including authentication, roots, and sampling.

For a more complete MCP debugging experience, check out the MCP Inspector.

Features

• Connect to local and remote MCP servers
• Easily browse available prompts, resources, and tools
• Call tools, generate prompts with arguments, and download resources

Getting Started

First, download the Companion app (requires macOS 15 or later).

Or, if you have Homebrew installed, you can run the following command:

brew install --cask mattt/tap/Companion

When you open the app, you'll see a sidebar on the left and a placeholder view on the right. Click the + button in the toolbar to add an MCP server.

[!TIP] Looking for a fun MCP server? Check out iMCP, which gives models access to your Messages, Contacts, Reminders and more.

Click on the iMCP menubar icon, select "Copy server command to clipboard", and paste that into the "Command" field for your STDIO server.

Once you add a server, it'll automatically connect. When it does, it'll show available prompts, resources, and tools. Click on one of those sections to see a list, and drill into whatever you're interested in. Or, select the parent item in the sidebar to get information about the server.

Requirements

• Xcode 16.3+
• macOS Sequoia 15+
• iOS / iPadOS 16+
• visionOS 2+

License

This project is available under the MIT license. See the LICENSE file for more info.

Legal

The app icon is a playful nod to Finder and Henohenomoheji (へのへのもへじ), a face drawn by Japanese schoolchildren using hiragana characters. Finder® is a trademark of Apple Inc.

This project is not affiliated with, endorsed, or sponsored by Apple Inc.