OpGen Password Generator MCP server

The opgen MCP Server is an implementation of the Model Context Protocol for password generation based on 1Password's SPG tool. It allows you to generate strong passwords that are automatically copied to your clipboard, making it easy to create secure passwords for your various accounts and services.

Installation

You can install the opgen MCP server using Go's install command:

go install github.com/syumai/opgen-mcp-server@latest

Configuration

To use the opgen MCP server, you need to configure it in your MCP client configuration file. There are two ways to set it up:

Direct Command Configuration

{
    "opgen": {
        "command": "opgen-mcp-server",
    }
}

Alternative Configuration using Go Run

{
    "opgen": {
        "command": "go",
        "args": ["run", "github.com/syumai/opgen-mcp-server@latest"],
    }
}

Available Tools

The opgen MCP server provides two main password generation tools:

Character-Based Password Generation

The generate_password_characters tool creates passwords based on character sets.

Configurable Options

• Password length: Define how long the password should be
• Allowed character sets: Which types of characters can be included
• Required character sets: Which types of characters must be included
• Excluded character sets: Which types of characters should not be used

Available Character Sets

• uppercase: Capital letters (A-Z)
• lowercase: Small letters (a-z)
• digits: Numbers (0-9)
• symbols: Special characters
• ambiguous: Characters that might be confused with others

Word-Based Password Generation

The generate_password_words tool creates passwords using words or syllables.

Configurable Options

• Number of words: How many words to include in the password

• Word list selection: Choose between:

  • words: Full words
  • syllables: Word parts

• Word separator type: Choose from:

  • hyphen: Words separated by -
  • space: Words separated by spaces
  • comma: Words separated by commas
  • period: Words separated by periods
  • underscore: Words separated by _
  • digit: Words separated by digits
  • none: No separators between words

• Capitalization scheme: Choose from:

  • none: No capitalization
  • first: First letter of each word capitalized
  • all: All letters capitalized
  • random: Random capitalization
  • one: One word fully capitalized

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 "opgen" '{"command":"opgen-mcp-server"}'

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": {
        "opgen": {
            "command": "opgen-mcp-server"
        }
    }
}

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": {
        "opgen": {
            "command": "opgen-mcp-server"
        }
    }
}

3. Restart Claude Desktop for the changes to take effect