Beginner guideSpec 2026-07-28
What Is an MCP Server? A Beginner’s Guide to the Model Context Protocol
Learn what an MCP server is, how hosts, clients, tools, resources and transports work, and how local and remote MCP differ in the current protocol.
Independent Model Context Protocol research
Understand MCP.
Know the version.
The protocol moved fast—and a lot of explanations did not. MCP Blog traces every important claim to a source and separates today’s stateless core from yesterday’s session-based model.
Protocol statusCurrent
202607.28
Stateless core. Self-contained requests. Discovery before invocation. Tasks as an extension.
Read the annotated change guide248Evidence records
109Official MCP sources
5Published spec versions traced
25 Aug 2026Corpus last verified
01
Why this site exists
“MCP” no longer describes one fixed architecture. It describes a protocol that crossed a major compatibility boundary.
Before July 2026, an MCP connection began with initialization and capability negotiation. The current core is stateless: requests carry their own context, servers advertise operations through discovery, and formerly core features can live as extensions.
That distinction changes how you explain MCP, design a server, debug a client, and assess security. Every technical page here names the protocol version it covers.
Evidence before opinion
Guides built to stay current
Foundations, architecture, migration, and security—each tied to a protocol revision and a public source trail.
Architecture comparisonSpec 2026-07-28
MCP vs Function Calling: Architecture, Differences, and When to Use Each
Compare MCP with native function calling and tool use. Learn how they work together, where APIs fit, their security and latency trade-offs, and when to use each.
Current specificationSpec 2026-07-28
MCP 2026-07-28: What Changed and How to Migrate
A practical guide to MCP's stateless 2026 specification, including per-request metadata, version discovery, multi-round trips, subscriptions, extensions, and legacy compatibility.
Start hereSpec 2026-07-28
What Is the Model Context Protocol? A Practical 2026 Guide
A version-aware explanation of MCP: the problem it solves, its architecture and capabilities, and how the stateless 2026 core differs from legacy MCP.
Architecture guideSpec 2026-07-28
How MCP Works: Hosts, Clients, Servers, and Every Request
A version-aware explanation of MCP architecture, primitives, message patterns, transports, and trust boundaries under the 2026-07-28 specification.
Migration guideSpec 2026-07-28
MCP Stateful-to-Stateless Migration: The 2026 Protocol
A practical migration guide from MCP's initialize-and-session era to the stateless 2026-07-28 protocol, with compatibility and state-design patterns.
Security field guideSpec 2026-07-28
MCP Security: Threats, Vulnerabilities, and How to Secure MCP Servers
A technical guide to MCP security covering OAuth, prompt injection, tool poisoning, malicious servers, CVEs, supply-chain risks, and secure local and remote deployment.
Transport guideSpec 2026-07-28
MCP Transports: stdio, Streamable HTTP, and Legacy SSE
Compare MCP stdio and current Streamable HTTP, and distinguish the 2024 HTTP+SSE and 2025 session-based wire models.
Protocol timelineSpec 2026-07-28
The History of MCP: From Early Commits to an Open Standard
A primary-source timeline of MCP, from its pre-launch repository and November 2024 announcement through adoption, open governance, and the stateless 2026 core.
ComparisonSpec 2026-07-28
MCP vs. APIs: Why Most AI Systems Need Both
MCP does not replace REST, GraphQL, RPC, or vendor SDKs. Learn what it standardizes at the AI boundary and where direct APIs still win.
Protocol comparisonSpec 2026-07-28
MCP vs. A2A: Tool Access and Agent Collaboration Explained
MCP connects AI applications to tools and context; A2A connects independent agents. Compare their roles, objects, and how they work together.
Our standard
Freshness is a feature, not a footnote.
Current and legacy behavior stay separate
Every technical guide states the specification revision it describes and labels compatibility-era details.
Claims lead back to evidence
Our public source library includes specifications, commits, standards, advisories, research, and first-party announcements.
No protocol vendor owns the conclusion
MCP Blog is not an official MCP property. Vendor claims are treated as claims, not proof of adoption or quality.
The protocol in motion
From first public commit to stateless core
Specification and SDK history begin before the public launch.
A stateful, JSON-RPC-based protocol with tools, resources, prompts, and more.
Streamable HTTP and a protocol authorization framework arrive.
MCP joins the Agentic AI Foundation under the Linux Foundation.
Stateless core, discovery, MRTR, extensions, and explicit deprecations.
Check our work
248 sources. Public, searchable, and linked.
The research corpus spans the protocol specification, repository history, RFCs, governance, SDKs, vendor adoption, security advisories, and academic work.
Open the source library