Module: McpHelper

Defined in:
lib/stack-service-base/mcp/mcp_helper.rb

Constant Summary collapse

VALID_TRANSPORTS = 
[:sse, :json].freeze

Class Method Summary collapse

Class Method Details

.included(base) ⇒ Object 



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# File 'lib/stack-service-base/mcp/mcp_helper.rb', line 22

def self.included(base)
  base.class_eval do

    error McpProcessor::ParseError do |err|
      status err.status
      err.body
    end

    get '/mcp' do
      content_type :json
      MCP_PROCESSOR.root_endpoint
    end

    post '/mcp' do
      request.body&.rewind

      response_body =
        begin
          MCP_PROCESSOR.rpc_endpoint(request.body.read.to_s)
        rescue McpProcessor::ParseError => e
          status e.status
          e.body
        end

      if response_body.nil?
        status 202
        headers 'Content-Length' => '0'
        ''
      elsif McpHelper.transport == :json
        content_type :json
        response_body
      else
        content_type 'text/event-stream'
        headers['Cache-Control'] = 'no-cache'
        headers['X-Accel-Buffering'] = 'no'
        headers['mcp-session-id'] = SecureRandom.uuid

        stream true do |s|
          s.callback { LOGGER.debug "stream closed: #{s}" }
          s << "event: message\ndata: #{response_body}\n\n"
          s.close
        end
      end
    end
  end
end

.transport ⇒ Object 



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# File 'lib/stack-service-base/mcp/mcp_helper.rb', line 10

def transport
  @transport ||= :sse
end

.transport=(value) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/stack-service-base/mcp/mcp_helper.rb', line 14

def transport=(value)
  value = value.to_sym
  raise ArgumentError, "Unknown MCP transport: #{value}" unless VALID_TRANSPORTS.include?(value)

  @transport = value
end