go-go-mcp

A Go implementation of the Model Context Protocol (MCP), providing a framework for building MCP servers and clients.

Installation

To install the go-go-mcp command line tool with homebrew, run:

brew tap go-go-golems/go-go-go
brew install go-go-golems/go-go-go/go-go-mcp

To install the go-go-mcp command using apt-get, run:

echo "deb [trusted=yes] https://apt.fury.io/go-go-golems/ /" >> /etc/apt/sources.list.d/fury.list
apt-get update
apt-get install go-go-mcp

To install using yum, run:

echo "
[fury]
name=Gemfury Private Repo
baseurl=https://yum.fury.io/go-go-golems/
enabled=1
gpgcheck=0
" >> /etc/yum.repos.d/fury.repo
yum install go-go-mcp

To install using go get, run:

go get -u github.com/go-go-golems/go-go-mcp/cmd/go-go-mcp

Finally, install by downloading the binaries straight from github.

Overview

This project implements the Model Context Protocol, which enables standardized communication between AI applications and language models. The implementation includes:

• MCP server and client

• Support for SSE and stdio transports

• Bridge to expose an SSE server as a stdio server

• Templated shell scripts as MCP tools

• Configuration files for profiles

• Core protocol message types and interfaces

• A modular registry system for managing prompts, resources, and tools

• Support for custom handlers and subscriptions

Supported Methods

The server implements the MCP specification methods:

• initialize - Protocol initialization and capability negotiation
• ping - Connection health check
• prompts/list - List available prompts
• prompts/get - Retrieve prompt content
• resources/list - List available resources
• resources/read - Read resource content
• tools/list - List available tools
• tools/call - Execute a tool

Not yet implemented:

• notifications
• resources/subscribe - Subscribe to resource updates

Running

Basic Usage

The binary can be run in a few different modes:

• Server mode: Run as an MCP server process
• Client mode: Use client commands to interact with an MCP server
• Bridge mode: Expose an SSE server as a stdio server

Server Mode

Start the server with either stdio or SSE transport:

# Start with stdio transport (default)
go-go-mcp server start --transport stdio

# Start with SSE transport
go-go-mcp server start --transport sse --port 3001

The server automatically watches configured repositories and files for changes, reloading tools when:

• Files are added or removed from watched directories
• Tool configuration files are modified
• Repository structure changes

This allows for dynamic tool updates without server restarts.

Server Tools

You can interact with tools directly without starting a server using the server tools commands:

# List available tools using the 'all' profile
go-go-mcp server tools list --profile all

# List only system monitoring tools
go-go-mcp server tools list --profile system

# Call a tool directly
go-go-mcp server tools call system-monitor --args format=json,metrics=cpu,memory

# Call a tool with JSON arguments
go-go-mcp server tools call calendar-event --json '{
  "title": "Team Meeting",
  "start_time": "2024-02-01 10:00",
  "duration": 60
}'

The available tools depend on the selected profile:

# System monitoring profile
go-go-mcp server tools list --profile system
# Shows: system-monitor, disk-usage, etc.

# Calendar profile
go-go-mcp server tools list --profile calendar
# Shows: calendar-event, calendar-availability, etc.

# Data analysis profile
go-go-mcp server tools list --profile data
# Shows: data-analyzer, data-visualizer, etc.

Client Mode

Use the client subcommand to interact with an MCP server:

# List available prompts (uses default server: go-go-mcp server start --transport stdio)
go-go-mcp client prompts list

# List available tools
go-go-mcp client tools list

# Execute a prompt with arguments
go-go-mcp client prompts execute hello --args '{"name":"World"}'

# Call a tool with arguments
go-go-mcp client tools call echo --args '{"message":"Hello, MCP!"}'

You can customize the server command and arguments if needed:

# Use a different server binary with custom arguments
go-go-mcp client --command custom-server,start,--debug,--port,8001 prompts list

# Use a server with a specific configuration
go-go-mcp client -c go-go-mcp,start,--config,config.yaml prompts list

Using go-go-mcp as a Bridge

go-go-mcp can be used as a bridge to expose an SSE server as a stdio server. This is useful when you need to connect a stdio-based client to an SSE server:

# Start an SSE server on port 3000
go-go-mcp server start --transport sse --port 3000

# In another terminal, start the bridge to expose the SSE server as stdio
go-go-mcp bridge --sse-url http://localhost:3000 --log-level debug

# Now you can use stdio-based clients to connect to the bridge

This is particularly useful when integrating with tools that only support stdio communication but need to connect to a web-based MCP server.

Debug Mode

Add the --debug flag to enable detailed logging:

go-go-mcp server start --debug 

Version Information

Check the version:

go-go-mcp -v

Configuration

go-go-mcp can be configured using YAML configuration files that allow you to:

• Define multiple profiles for different environments
• Configure tool and prompt sources
• Set parameter defaults and overrides
• Control access through blacklists/whitelists
• Manage security through parameter filtering

Command-Line Configuration Management

The config command group provides tools to manage your configuration:

# Create a new configuration file
go-go-mcp config init

# Edit configuration in your default editor
go-go-mcp config edit

# List available profiles
go-go-mcp config list-profiles

# Show details of a specific profile
go-go-mcp config show-profile default

# Add a tool directory to a profile
go-go-mcp config add-tool default --dir ./tools/system

# Add a specific tool file to a profile
go-go-mcp config add-tool default --file ./tools/special-tool.yaml

# Create a new profile
go-go-mcp config add-profile production "Production environment configuration"

# Duplicate an existing profile
go-go-mcp config duplicate-profile development staging "Staging environment configuration"

# Set the default profile
go-go-mcp config set-default-profile production

For detailed configuration documentation, use:

# View configuration file documentation
go-go-mcp help config-file

# View example configuration
go-go-mcp help config-file --example

Shell Commands

go-go-mcp supports defining custom shell commands in YAML files, providing:

• Template-based command generation with Go templates and Sprig functions
• Rich parameter type system
• Environment variable management
• Working directory control
• Error handling and output capture

Example Commands

The examples/ directory contains various ready-to-use commands. You can view the schema for any command using go-go-mcp schema <command.yaml>, which shows the full parameter documentation that is passed to the LLM:

go-go-mcp schema examples/github/list-github-issues.yaml

GitHub Integration

• examples/github/list-github-issues.yaml - List and filter GitHub issues
• examples/github/list-pull-requests.yaml - List and filter pull requests

Web Content Tools

• examples/shell-commands/fetch-url.yaml - Fetch and process web content
• examples/html-extract/pubmed.yaml - Search and extract data from PubMed

Research and Documentation

• examples/shell-commands/diary-append.yaml - Maintain a timestamped diary
• examples/shell-commands/fetch-transcript.yaml - Download YouTube video transcripts

For any command, you can view its full schema and documentation using:

# View the full parameter schema and documentation
go-go-mcp schema examples/github/list-github-issues.yaml

# View the command help
go-go-mcp run-command examples/github/list-github-issues.yaml --help

Running Shell Commands Directly

You can run shell commands directly using the run-command subcommand. This allows you to execute any shell command YAML file without loading it into a server first:

# View command help and available flags
go-go-mcp run-command examples/github/list-github-issues.yaml --help

# Run a command with specific parameters
go-go-mcp run-command examples/github/list-github-issues.yaml --author wesen

# Run a Google Calendar command
go-go-mcp run-command examples/google/get-calendar.yaml --start today --end "next week"

# Run a URL fetching command
go-go-mcp run-command examples/shell-commands/fetch-url.yaml --url https://example.com

This provides a simpler way to use shell commands as standalone command-line tools without setting up a server.

Generating Shell Commands with Pinocchio

You can use Pinocchio to generate shell commands for go-go-mcp. First, add your local go-go-mcp repository as a Pinocchio repository:

pinocchio config repositories add $(pwd)/pinocchio

Then generate a new command using:

pinocchio go-go-mcp create-command --description "A command description"

This will create a new shell command YAML file with the appropriate structure and configuration.

For detailed shell commands documentation, use:

# View shell commands documentation
go-go-mcp help shell-commands

# View example shell commands
go-go-mcp help shell-commands --example

Help System

go-go-mcp comes with comprehensive built-in documentation. To explore:

# List all available help topics
go-go-mcp help --all

# Get help on a specific topic
go-go-mcp help <topic>

# Show examples for a topic
go-go-mcp help <topic> --example

UI DSL

A simple YAML-based Domain Specific Language for defining user interfaces.

Components

The DSL supports the following basic components:

Button

• text: Button label
• type: primary, secondary, danger, success
• onclick: JavaScript event handler

Title

• content: Heading text content

Text

• content: Text content

Input

• type: text, email, password, number, tel
• placeholder: Placeholder text
• value: Default value
• required: Boolean

Textarea

• placeholder: Placeholder text
• rows: Number of rows
• cols: Number of columns
• value: Default value

Checkbox

• label: Checkbox label
• checked: Boolean
• required: Boolean
• name: Form field name

List

• type: ul or ol
• items: Array of items or nested components

Common Attributes

All components support these common attributes:

• id: Unique identifier
• style: Inline CSS
• disabled: Boolean
• data: Map of data attributes

Example

form:
  id: signup-form
  components:
    - title:
        content: Sign Up
    - text:
        content: Please fill in your details below.
    - input:
        type: email
        placeholder: Email address
    - button:
        text: Submit
        type: primary

See ui-dsl.yaml for more comprehensive examples.