Claude Desktop

Claude Desktop supports servers through a JSON config file. The file location depends on your operating system.

Claude Desktop must be fully restarted (quit and reopen, not just start a new conversation) after any config change. This is the most common setup issue.

Setup

Open the config file

The config file location depends on your OS:

macOS
Windows
Linux

~/Library/Application Support/Claude/claude_desktop_config.json

Open it in your editor, or run:

open ~/Library/Application\ Support/Claude/claude_desktop_config.json

%APPDATA%\Claude\claude_desktop_config.json

Open it in your editor, or press Win+R and paste the path above.

~/.config/Claude/claude_desktop_config.json

If the file doesn’t exist, create it.

Add the OpenCX server

Paste this into your config file:

{
  "mcpServers": {
    "opencx": {
      "command": "npx",
      "args": ["-y", "@opencx/mcp"],
      "env": {
        "OPENCX_API_KEY": "your-api-key-here"
      }
    }
  }
}

Replace your-api-key-here with your OpenCX API key.

To use the hosted endpoint instead of running the server locally, bridge it with mcp-remote (Claude Desktop’s connector UI doesn’t support custom auth headers):

{
  "mcpServers": {
    "opencx": {
      "command": "npx",
      "args": [
        "-y",
        "mcp-remote",
        "https://api.open.cx/mcp",
        "--header",
        "Authorization: Bearer your-api-key-here"
      ]
    }
  }
}

Restart Claude Desktop

Fully quit Claude Desktop (not just close the window) and reopen it. On macOS, use Cmd+Q. On Windows, right-click the system tray icon and select Quit.

Verify

Look for the hammer icon in the chat input area. Click it to see connected MCP servers and available tools. Then ask: “List my recent chat sessions.”

The MCP Indicator

Once connected, a hammer icon appears next to the chat input. Click it to see:

Which MCP servers are connected
How many tools are available
Individual tool names (click to expand)

If the hammer icon doesn’t appear, the config file isn’t being read. Double-check the file path and restart Claude Desktop.

Multiple MCP Servers

Add other MCP servers alongside OpenCX in the same mcpServers object:

{
  "mcpServers": {
    "opencx": {
      "command": "npx",
      "args": ["-y", "@opencx/mcp"],
      "env": {
        "OPENCX_API_KEY": "your-opencx-key"
      }
    },
    "another-server": {
      "command": "npx",
      "args": ["-y", "@another/mcp-server"],
      "env": {
        "API_KEY": "your-other-key"
      }
    }
  }
}

Each server runs as a separate process. Claude Desktop makes tools from all connected servers available in every conversation.

Common Issues

Symptom	Fix
Hammer icon missing	Check config file path and JSON syntax. Restart Claude Desktop fully.
Tools appear but fail with 401	API key is invalid or revoked. Generate a new one in your dashboard.
”Server disconnected” after idle	Claude Desktop may stop idle MCP servers. Start a new conversation to reconnect.

Claude Code

CLI-based MCP setup in the same Claude family

Get Started

API key setup and all client configs

Prompt Library

Ready-to-use prompts by domain

Troubleshooting

Common issues and fixes

Overview

Client Guides

Reference

Setup

The MCP Indicator

Multiple MCP Servers

Common Issues

Claude Code

Get Started

Prompt Library

Troubleshooting

​Setup

​The MCP Indicator

​Multiple MCP Servers

​Common Issues

​Related Documentation

Claude Code

Get Started

Prompt Library

Troubleshooting

Setup

The MCP Indicator

Multiple MCP Servers

Common Issues

Related Documentation