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Welcome to TheMCPGuy

The definitive learning resource for Model Context Protocol, the open standard that connects AI to the real world.

Version Baseline (as of 2026-07)

Code, API references, and version pins across this site target:

  • MCP spec: 2026-07-28 is the current stable revision, ratified 28 July 2026. The code on this site targets 2025-11-25, because the Java MCP SDK 2.0.0 implements that revision and has not yet shipped 2026-07-28 support. This is a deliberate choice: we pin to what the SDK can actually run. 2026-07-28 is a large revision, it removes protocol-level sessions and the initialize handshake, replaces server-initiated requests with the Multi Round-Trip Requests pattern, and deprecates Roots, Sampling and Logging. Courses are being revised against it; lessons that teach a changed mechanism will say so.
  • Java MCP SDK: io.modelcontextprotocol.sdk:mcp 2.0.0 GA (released 2026-06-11; tracks the 2025-11-25 spec). The previous 1.1.x line is still patched (latest 1.1.3) and 1.0.x still receives fixes (latest 1.0.2). The SDK follows SemVer; the project does not officially designate any "LTS" line.
  • Spring AI: 2.0.0 GA (the 2.x line targets Spring Boot 4.x). The previous 1.1.x line is still maintained (latest 1.1.8) and 1.0.x still supported (latest 1.0.9).
  • Spring Boot: 4.1.0 GA; this is the line the GA Spring AI 2.0.0 and Java MCP SDK 2.0.0 build on. Spring Boot 4 means Spring Framework 7, Jakarta EE 11 (Servlet 6.1), Spring Security 7, Jackson 3, and a Java 17+ baseline. Spring Boot 3.5.x is still patched (latest 3.5.16) for projects staying on the previous 1.1.x stack.
  • Spring Security: 7.x (was 6.5.x on the Boot 3.5 stack)
  • Java: 17 minimum, 21 recommended
  • Anthropic Claude models: Sonnet 4.6, Haiku 4.5, Opus 4.8 (current flagship; Opus 4.7 is now legacy)

MCP, Spring AI, and the LLM ecosystem move fast. Before starting a project, sanity-check Maven Central / docs.spring.io / docs.anthropic.com for current versions and rerun any version-pinned snippets against them.

Why TheMCPGuy?​

MCP is moving fast. Anthropic published the spec. GitHub, Cursor (an AI code editor), and Zed (a modern code editor) adopted it. Hundreds of community servers appeared overnight. But the educational resources? Scattered, shallow, and usually missing the why.

This site exists to fix that. You'll find:

Courses That Explain the Why​

Every tutorial here covers why a design decision exists, not just how to implement it. Protocol design involves trade-offs. Understanding them makes you a better MCP server author, and a better engineer.

Technology-Agnostic Foundations​

Before you touch code, understand the protocol. The MCP Fundamentals course is language-agnostic: it teaches the spec, the architecture, and the primitives. Come back to it every time you're confused about why something works the way it does.

Java-First Practical Courses​

The Java ecosystem is underrepresented in the MCP world. Most examples are Python or TypeScript. We're changing that. Our Java SDK course covers everything from Hello, MCP to production deployment, with Spring Boot, real tooling, and tests.

Who Is This For?​

This site is for you if:
  • You're a backend developer curious about AI integration
  • You want to understand MCP before you start writing servers
  • You're a Java developer tired of Python-only examples
  • You want depth, not just copy-paste code snippets

Available Now​

1. MCP Fundamentals (Start Here)​

Technology-agnostic. Eight modules covering the protocol spec from first principles, what problem MCP solves, how the architecture works, what Tools/Resources/Prompts really mean, how transports work, and how the security model is designed.

→ Start MCP Fundamentals

2. Building MCP Servers in Java​

Nine hands-on modules. You'll build real MCP servers using the official Java SDK, implement all three primitives, handle errors properly, write tests, and deploy to production.

→ Start the Java SDK Course

3. Spring AI + MCP Integration​

Eight hands-on modules. Build AI agents that consume MCP servers with Spring AI's ChatClient, expose Spring services as MCP tools with @McpTool, and ship production-grade Spring Boot deployments.

→ Start the Spring AI + MCP Course

In Preparation​

These courses are written and are being re-verified against the current spec and SDK releases before they go live. They will be published one at a time.

4. MCP Architecture Patterns​

Eight design-focused modules for senior engineers. Server composition, tool granularity, primitive selection, multi-tenant architecture, caching, versioning, and resilience. The patterns that separate "writing an MCP server" from "designing an MCP system".

Coming soon.

5. Remote MCP Servers​

Eight modules on taking MCP beyond stdio. Streamable HTTP transport in depth, OAuth 2.1 with PKCE and RFC 8707, permission models, rate limiting, Kubernetes deployment, and operating remote MCP in production.

Coming soon.

6. Securing Production MCP​

Eight security-focused modules. The MCP threat model, authentication beyond OAuth, authorisation patterns (RBAC/ABAC/ReBAC), sandboxing, prompt injection defenses, supply chain controls, and audit/incident response.

Coming soon.

7. Testing & Observability​

Eight modules on testing AI applications without burning API credits and observing them once they ship. Unit tests, Testcontainers, protocol-level testing, ChatModel mocking, contract testing, structured observability, and production debugging.

Coming soon.

8. MCP in Agentic Workflows​

Eight modules on building genuine agents on top of MCP. Planning, memory, tool composition, human-in-the-loop approval, multi-agent orchestration, evaluation, and the cost levers that make agents affordable in production.

Coming soon.

9. Context Engineering for MCP​

Seven modules on the token economics of MCP. Why your context window fills up before the user even types, how code execution and progressive disclosure shrink it by an order of magnitude, and how to measure the savings honestly. Backed by a runnable Java project.

Coming soon.

10. MCP Client & Host Development​

Eight modules on building the other half of MCP: the host and client that negotiate capabilities, drive sampling and elicitation, render MCP Apps, and discover servers. Includes a runnable Java host capstone.

Coming soon.

11. Building MCP Apps (Interactive UI)​

Eight modules on MCP's first official extension. Build sandboxed widgets that render inside the chat and talk back to the host through the consent path. Java server, web widget, and the security model that makes the whole thing safe.

Coming soon.

12. Authorization for MCP (OAuth 2.1 / OIDC)​

Seven modules on the 2025-11-25 authorization overhaul. OIDC Discovery, Protected Resource Metadata, Client ID Metadata Documents, incremental scope consent, and stateless JWT validation, implemented with Spring Security.

Coming soon.

13. MCP at Scale: Stateless & Horizontal Scaling​

Eight modules on running remote MCP servers behind a load balancer without the session pain. Stateless transport, explicit state handles, horizontal scaling patterns, and Streamable HTTP. Protocol-level session removal is ratified in the 2026-07-28 spec; the Java SDK is still catching up.

Coming soon.

The MCP Spec​

Everything taught here aligns with the official MCP specification at modelcontextprotocol.io/specification. When in doubt, the spec is authoritative. This site provides the context that makes the spec readable.

Let's build things that actually work.