https://github.com/funwarioisii/mcp-rb
A lightweight Ruby framework for building MCP servers with a Sinatra-like DSL
https://github.com/funwarioisii/mcp-rb
mcp-server modelcontextprotocol
Last synced: about 2 months ago
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A lightweight Ruby framework for building MCP servers with a Sinatra-like DSL
- Host: GitHub
- URL: https://github.com/funwarioisii/mcp-rb
- Owner: funwarioisii
- License: mit
- Created: 2025-02-12T15:07:13.000Z (3 months ago)
- Default Branch: master
- Last Pushed: 2025-03-12T04:03:12.000Z (about 2 months ago)
- Last Synced: 2025-03-12T05:18:41.242Z (about 2 months ago)
- Topics: mcp-server, modelcontextprotocol
- Language: Ruby
- Homepage: https://rubygems.org/gems/mcp-rb
- Size: 116 KB
- Stars: 31
- Watchers: 1
- Forks: 4
- Open Issues: 4
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE.txt
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README
# MCP-RB
A lightweight Ruby framework for implementing MCP (Model Context Protocol) servers with a Sinatra-like DSL.
## Installation
Add this line to your application's Gemfile:
```ruby
gem 'mcp-rb'
```
## Usage
Here's a simple example of how to create an MCP server:
```ruby
require 'mcp'
name "hello-world"
version "1.0.0"
# Define a resource
resource "hello://world" do
name "Hello World"
description "A simple hello world message"
call { "Hello, World!" }
end
# Define a resource template
resource_template "hello://{user_name}" do
name "Hello User"
description "A simple hello user message"
call { |args| "Hello, #{args[:user_name]}!" }
end
# Define a tool
tool "greet" do
description "Greet someone by name"
argument :name, String, required: true, description: "Name to greet"
call do |args|
"Hello, #{args[:name]}!"
end
end
# Define a tool with nested arguments
tool "greet_full_name" do
description "Greet someone by their full name"
argument :person, required: true, description: "Person to greet" do
argument :first_name, String, required: false, description: "First name"
argument :last_name, String, required: false, description: "Last name"
end
call do |args|
"Hello, First: #{args[:person][:first_name]} Last: #{args[:person][:last_name]}!"
end
end
# Define a tool with an Array argument
tool "group_greeting" do
description "Greet multiple people at once"
argument :people, Array, required: true, items: String, description: "People to greet"
call do |args|
args[:people].map { |person| "Hello, #{person}!" }.join(", ")
end
end
```
## Supported specifications
Reference: [MCP 2024-11-05](https://spec.modelcontextprotocol.io/specification/2024-11-05/)
- [Base Protocol](https://spec.modelcontextprotocol.io/specification/2024-11-05/basic/)
- ping
- stdio transport
- [Server features](https://spec.modelcontextprotocol.io/specification/2024-11-05/server/)
- Resources
- resources/read
- resources/list
- resources/templates/list
- Tools
- tools/list
- tools/call
Any capabilities are not supported yet.
## Testing
```bash
ruby -Ilib:test -e "Dir.glob('./test/**/*_test.rb').each { |f| require f }"
```
Test with MCP Inspector
```bash
bunx @modelcontextprotocol/inspector $(pwd)/examples/hello_world.rb
```
Find broken using `hello_world.rb`
```bash
./test/test_requests.sh
```
## Formatting
```bash
bundle exec standardrb --fix
```
## Release
To release a new version:
1. Update version in `lib/mcp/version.rb`
2. Update `CHANGELOG.md`
3. Create a git tag
```bash
git add .
git commit -m "Release vx.y.z"
git tag vx.y.z
git push --tags
```
1. Build and push to RubyGems
```bash
gem build mcp-rb.gemspec
gem push mcp-rb-*.gem
```
## Changelog
See [CHANGELOG.md](CHANGELOG.md)