Chapter 8: Production Deployment and Upgrade Strategy

Welcome to Chapter 8: Production Deployment and Upgrade Strategy. In this part of MCP Ruby SDK Tutorial: Building MCP Servers and Clients in Ruby, you will build an intuitive mental model first, then move into concrete implementation details and practical production tradeoffs.

This chapter defines practical production controls for Ruby MCP services and clients.

Learning Goals

• choose deployment topology by transport/session requirements
• operate rolling upgrades with compatibility checks
• keep logging, notifications, and resource limits production-safe
• maintain protocol alignment across multi-service environments

Production Controls

1. separate local stdio tooling from public HTTP deployment boundaries
2. set request/session timeouts and payload guardrails
3. monitor notification backlog and transport error rates
4. validate protocol compatibility before gem upgrades
5. run canary rollout steps before full fleet updates

Source References

• Ruby SDK README
• Ruby Examples
• Ruby SDK Changelog
• MCP Specification

Summary

You now have a production rollout and upgrade strategy for Ruby MCP implementations.

Return to the MCP Ruby SDK Tutorial index.

Source Code Walkthrough

.rubocop.yml

The .rubocop module in .rubocop.yml handles a key part of this chapter's functionality:

inherit_gem:
  rubocop-shopify: rubocop.yml

plugins:
  - rubocop-minitest
  - rubocop-rake

AllCops:
  TargetRubyVersion: 2.7

Gemspec/DevelopmentDependencies:
  Enabled: true

Lint/IncompatibleIoSelectWithFiberScheduler:
  Enabled: true

Minitest/LiteralAsActualArgument:
  Enabled: true

This module is important because it defines how MCP Ruby SDK Tutorial: Building MCP Servers and Clients in Ruby implements the patterns covered in this chapter.

conformance/server.rb

The server module in conformance/server.rb handles a key part of this chapter's functionality:

# frozen_string_literal: true

require "rackup"
require "json"
require "uri"
require_relative "../lib/mcp"

module Conformance
  # 1x1 red PNG pixel (matches TypeScript SDK and Python SDK)
  BASE64_1X1_PNG = "iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8z8DwHwAFBQIAX8jx0gAAAABJRU5ErkJggg=="

  # Minimal WAV file (matches TypeScript SDK and Python SDK)
  BASE64_MINIMAL_WAV = "UklGRiYAAABXQVZFZm10IBAAAAABAAEAQB8AAAB9AAACABAAZGF0YQIAAAA="

  module Tools
    class TestSimpleText < MCP::Tool
      tool_name "test_simple_text"
      description "A tool that returns simple text content"

      class << self
        def call(**_args)
          MCP::Tool::Response.new([MCP::Content::Text.new("This is a simple text response for testing.").to_h])
        end
      end
    end

    class TestImageContent < MCP::Tool
      tool_name "test_image_content"
      description "A tool that returns image content"

      class << self
        def call(**_args)
          MCP::Tool::Response.new([MCP::Content::Image.new(BASE64_1X1_PNG, "image/png").to_h])
        end
      end

This module is important because it defines how MCP Ruby SDK Tutorial: Building MCP Servers and Clients in Ruby implements the patterns covered in this chapter.

lib/json_rpc_handler.rb

The json_rpc_handler module in lib/json_rpc_handler.rb handles a key part of this chapter's functionality:

# frozen_string_literal: true

require "json"

module JsonRpcHandler
  class Version
    V1_0 = "1.0"
    V2_0 = "2.0"
  end

  class ErrorCode
    INVALID_REQUEST = -32600
    METHOD_NOT_FOUND = -32601
    INVALID_PARAMS = -32602
    INTERNAL_ERROR = -32603
    PARSE_ERROR = -32700
  end

  DEFAULT_ALLOWED_ID_CHARACTERS = /\A[a-zA-Z0-9_-]+\z/

  extend self

  def handle(request, id_validation_pattern: DEFAULT_ALLOWED_ID_CHARACTERS, &method_finder)
    if request.is_a?(Array)
      return error_response(id: :unknown_id, id_validation_pattern: id_validation_pattern, error: {
        code: ErrorCode::INVALID_REQUEST,
        message: "Invalid Request",
        data: "Request is an empty array",
      }) if request.empty?

      # Handle batch requests
      responses = request.map { |req| process_request(req, id_validation_pattern: id_validation_pattern, &method_finder) }.compact

      # A single item is hoisted out of the array
      return responses.first if responses.one?

This module is important because it defines how MCP Ruby SDK Tutorial: Building MCP Servers and Clients in Ruby implements the patterns covered in this chapter.

How These Components Connect

flowchart TD
    A[.rubocop]
    B[server]
    C[json_rpc_handler]
    A --> B
    B --> C