Class: LanguageOperator::Dsl::Adapter

Inherits:
Object
  • Object
show all
Defined in:
lib/language_operator/dsl/adapter.rb

Overview

Adapter to bridge our DSL to the official MCP Ruby SDK

Converts LanguageOperator::Dsl::ToolDefinition objects into MCP::Tool classes that can be used with the official MCP Ruby SDK.

Examples:

Convert a tool definition

tool_class = Adapter.tool_definition_to_mcp_tool(tool_def)
server = MCP::Server.new(tools: [tool_class])

Class Method Summary collapse

Class Method Details

.build_input_schema(parameters) ⇒ Object

Build MCP input schema from our parameter definitions



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# File 'lib/language_operator/dsl/adapter.rb', line 59

def self.build_input_schema(parameters)
  properties = {}
  required = []

  parameters.each do |name, param_def|
    properties[name.to_sym] = build_parameter_schema(param_def)
    required << name if param_def.required
  end

  schema = { properties: properties }
  schema[:required] = required unless required.empty?
  schema
end

.build_parameter_schema(param_def) ⇒ Object

Build schema for a single parameter



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# File 'lib/language_operator/dsl/adapter.rb', line 74

def self.build_parameter_schema(param_def)
  # Access instance variables directly since the DSL methods are setters
  param_type = param_def.instance_variable_get(:@type)
  param_desc = param_def.instance_variable_get(:@description)
  param_enum = param_def.instance_variable_get(:@enum)
  param_default = param_def.instance_variable_get(:@default)

  schema = {
    type: map_type(param_type),
    description: param_desc || '' # MCP requires description to be a string
  }

  schema[:enum] = param_enum if param_enum
  schema[:default] = param_default if param_default

  schema
end

.create_mcp_server(registry, server_name: 'langop-mcp', server_context: {}) ⇒ Object

Create an MCP::Server from our registry



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# File 'lib/language_operator/dsl/adapter.rb', line 112

def self.create_mcp_server(registry, server_name: 'langop-mcp', server_context: {})
  tools = registry_to_mcp_tools(registry)

  MCP::Server.new(
    name: server_name,
    version: LanguageOperator::VERSION,
    tools: tools,
    server_context: server_context
  )
end

.map_type(ruby_type) ⇒ Object

Map our type symbols to JSON schema types



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# File 'lib/language_operator/dsl/adapter.rb', line 93

def self.map_type(ruby_type)
  case ruby_type
  when :string then 'string'
  when :number, :integer then 'number'
  when :boolean then 'boolean'
  when :array then 'array'
  when :object then 'object'
  else 'string'
  end
end

.registry_to_mcp_tools(registry) ⇒ Object

Convert a registry of tools to MCP::Tool classes



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# File 'lib/language_operator/dsl/adapter.rb', line 105

def self.registry_to_mcp_tools(registry)
  registry.all.map do |tool_def|
    tool_definition_to_mcp_tool(tool_def)
  end
end

.tool_definition_to_mcp_tool(tool_def) ⇒ Object

Convert our ToolDefinition to an MCP::Tool class



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# File 'lib/language_operator/dsl/adapter.rb', line 17

def self.tool_definition_to_mcp_tool(tool_def)
  # Build input schema from our parameter definitions
  schema = build_input_schema(tool_def.parameters)

  # Create a dynamic class that extends MCP::Tool
  Class.new(MCP::Tool) do
    # Set the tool name using the MCP SDK's method
    tool_name tool_def.name

    # Set the description
    description tool_def.description

    # Set input schema
    input_schema(schema)

    # Define the call method
    define_singleton_method(:call) do |server_context: {}, **args|
      # Convert args to string keys to match our DSL expectations
      params = args.transform_keys(&:to_s)

      # Execute the tool using our DSL
      result = tool_def.call(params)

      # Convert result to MCP::Tool::Response
      MCP::Tool::Response.new([
                                { type: 'text', text: result.to_s }
                              ])
    rescue ArgumentError => e
      # Return error as text response
      MCP::Tool::Response.new([
                                { type: 'text', text: "Error: #{e.message}" }
                              ])
    rescue StandardError => e
      # Return error as text response
      MCP::Tool::Response.new([
                                { type: 'text', text: "Error: #{e.message}" }
                              ])
    end
  end
end