Skip to main content
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

1

Open the config file

The config file location depends on your OS:
~/Library/Application Support/Claude/claude_desktop_config.json
Open it in your editor, or run:
open ~/Library/Application\ Support/Claude/claude_desktop_config.json
If the file doesn’t exist, create it.
2

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.
3

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.
4

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

SymptomFix
Hammer icon missingCheck config file path and JSON syntax. Restart Claude Desktop fully.
Tools appear but fail with 401API key is invalid or revoked. Generate a new one in your dashboard.
”Server disconnected” after idleClaude 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