Skip to main content

​
Claude Desktop Integration

This guide shows how to configure Overwatch with Claude Desktop to protect MCP server tool calls.

​
Prerequisites

  • Claude Desktop installed
  • Overwatch installed (npm install -g @dotsetlabs/overwatch)
  • An MCP server to protect

​
Quick Setup

​
1. Locate Config File

Claude Desktop’s configuration file:
PlatformPath
macOS~/Library/Application Support/Claude/claude_desktop_config.json
Windows%APPDATA%\Claude\claude_desktop_config.json
Linux~/.config/Claude/claude_desktop_config.json

​
2. Wrap MCP Servers

Instead of calling the MCP server directly, wrap it with Overwatch. Before: 
{
  "mcpServers": {
    "postgres": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-postgres"],
      "env": {
        "DATABASE_URL": "postgres://localhost/mydb"
      }
    }
  }
}
After: 
{
  "mcpServers": {
    "postgres": {
      "command": "npx",
      "args": [
        "-y", "@dotsetlabs/overwatch", "wrap",
        "npx", "-y", "@modelcontextprotocol/server-postgres"
      ],
      "env": {
        "DATABASE_URL": "postgres://localhost/mydb"
      }
    }
  }
}

​
3. Restart Claude Desktop

After saving the config, restart Claude Desktop for changes to take effect.

​
Example Configurations

​
Filesystem Server

{
  "mcpServers": {
    "filesystem": {
      "command": "npx",
      "args": [
        "-y", "@dotsetlabs/overwatch", "wrap",
        "npx", "-y", "@anthropic/mcp-server-filesystem", "./"
      ]
    }
  }
}

​
GitHub Server

{
  "mcpServers": {
    "github": {
      "command": "npx",
      "args": [
        "-y", "@dotsetlabs/overwatch", "wrap",
        "npx", "-y", "@anthropic/mcp-server-github"
      ],
      "env": {
        "GITHUB_TOKEN": "your-token"
      }
    }
  }
}

​
Multiple Servers

{
  "mcpServers": {
    "postgres": {
      "command": "npx",
      "args": [
        "-y", "@dotsetlabs/overwatch", "wrap",
        "npx", "-y", "@modelcontextprotocol/server-postgres"
      ],
      "env": {
        "DATABASE_URL": "postgres://localhost/mydb"
      }
    },
    "filesystem": {
      "command": "npx",
      "args": [
        "-y", "@dotsetlabs/overwatch", "wrap",
        "npx", "-y", "@anthropic/mcp-server-filesystem", "./"
      ]
    }
  }
}

​
Using a Config File

For more control, create overwatch.yaml and use overwatch start:

​
1. Create Config

# overwatch.yaml
version: 1

defaults:
  action: prompt

servers:
  postgres:
    command: npx
    args: ["-y", "@modelcontextprotocol/server-postgres"]
    env:
      DATABASE_URL: postgres://localhost/mydb
    policies:
      - tools: ["query", "select"]
        action: allow
      - tools: ["insert", "update"]
        action: prompt
      - tools: ["drop_*", "delete_*"]
        action: deny

  filesystem:
    command: npx
    args: ["-y", "@anthropic/mcp-server-filesystem", "./"]
    policies:
      - tools: ["read_*"]
        action: allow
      - tools: ["write_*", "delete_*"]
        action: prompt

toolShadowing:
  enabled: true
  checkDescriptions: true
  detectMutations: true

​
2. Update Claude Desktop Config

{
  "mcpServers": {
    "overwatch": {
      "command": "npx",
      "args": ["-y", "@dotsetlabs/overwatch", "start"]
    }
  }
}

​
Approval Flow

When Claude makes a tool call:
  1. Overwatch intercepts the call
  2. Checks for tool shadowing
  3. Applies policies
  4. If approval needed, prompts in terminal
  5. Claude waits for your decision
  6. Approved calls proceed; denied calls fail gracefully

​
Troubleshooting

​
Overwatch Not Prompting

Make sure Claude Desktop can access your terminal. Prompts appear in the terminal where Claude Desktop was started.

​
npx Cache Issues

If npx has cached an old version: 
npx clear-npx-cache

​
Config Syntax Errors

Validate JSON syntax: 
cat ~/Library/Application\ Support/Claude/claude_desktop_config.json | jq .

​
Logs

Check Overwatch logs: 
overwatch logs --since 1h