ruby-sdk/lib/mcp/prompt.rb
2025-05-29 17:11:40 -04:00

82 lines
2 KiB
Ruby

# typed: strict
# frozen_string_literal: true
module MCP
class Prompt
class << self
NOT_SET = Object.new
attr_reader :description_value
attr_reader :arguments_value
def template(args, server_context:)
raise NotImplementedError, "Subclasses must implement template"
end
def to_h
{ name: name_value, description: description_value, arguments: arguments_value.map(&:to_h) }.compact
end
def inherited(subclass)
super
subclass.instance_variable_set(:@name_value, nil)
subclass.instance_variable_set(:@description_value, nil)
subclass.instance_variable_set(:@arguments_value, nil)
end
def prompt_name(value = NOT_SET)
if value == NOT_SET
@name_value
else
@name_value = value
end
end
def name_value
@name_value || StringUtils.handle_from_class_name(name)
end
def description(value = NOT_SET)
if value == NOT_SET
@description_value
else
@description_value = value
end
end
def arguments(value = NOT_SET)
if value == NOT_SET
@arguments_value
else
@arguments_value = value
end
end
def define(name: nil, description: nil, arguments: [], &block)
Class.new(self) do
prompt_name name
description description
arguments arguments
define_singleton_method(:template) do |args, server_context:|
instance_exec(args, server_context:, &block)
end
end
end
def validate_arguments!(args)
missing = required_args - args.keys
return if missing.empty?
raise MCP::Server::RequestHandlerError.new(
"Missing required arguments: #{missing.join(", ")}", nil, error_type: :missing_required_arguments
)
end
private
def required_args
arguments_value.filter_map { |arg| arg.name.to_sym if arg.required }
end
end
end
end