101 · 15 canons

MCP

The protocol's original motivation, current architecture, secure transport and the maintainer decisions that turned a connector format into shared infrastructure.

TL;DR MCP standardizes how AI hosts connect to tools, resources and prompts. Read the architecture and transport specs first; then study authorization, client behavior and governance before copying a demo server into production.

Curated by Ali Abouelatta

Cofounder of Lazyweb (a16z Speedrun). Previously grew subscriptions and built native ads at Duolingo. Writes First1000 (90,000+ subscribers).

Voices in this 101

Reading path 1

Understand the protocol

These sources establish MCP's original problem and its current host-client-server model before implementation details obscure the point.

01
Introducing the Model Context Protocol ↗
Alex Albert
Anthropic developer-relations leader and early public voice for MCP.
TL;DR
MCP was introduced as an open standard that replaces one-off data integrations with a common connection between AI applications and external systems.
What you'll read
The launch thesis, early architecture, initial SDKs and the ecosystem problem Anthropic intended the protocol to solve.
02
MCP architecture ↗
David Soria Parra
MCP co-inventor and lead maintainer.
TL;DR
A host owns user experience and security boundaries, clients maintain one server connection each, and servers expose focused context and capabilities.
What you'll read
The authoritative host-client-server roles, isolation boundaries, capability negotiation and design principles.
03
MCP base protocol ↗
Justin Spahr-Summers
MCP co-inventor and lead maintainer emeritus.
TL;DR
MCP is a stateful JSON-RPC protocol with initialization, negotiated capabilities, notifications and explicit lifecycle behavior.
What you'll read
Message shapes, request and notification rules, initialization, capability exchange and the primitives every SDK must preserve.
04
MCP transports ↗
David Soria Parra
MCP co-inventor and lead maintainer.
TL;DR
Local stdio and remote Streamable HTTP solve different connection problems while carrying the same protocol messages.
What you'll read
Transport requirements, session handling, origin checks, protocol-version headers and why old HTTP+SSE assumptions no longer define remote MCP.
05
MCP server primitives ↗
Justin Spahr-Summers
MCP co-inventor and lead maintainer emeritus.
TL;DR
Servers can expose prompts, resources and tools; treating all three as interchangeable functions throws away useful protocol semantics.
What you'll read
The server capability model and the distinct jobs of prompts, resources, tools and utility features.

Reading path 2

Build reliable servers

A production server is mostly boundaries: transport, authorization, validation, cancellation, discovery and recovery.

06
Build an MCP server ↗
David Soria Parra
MCP co-inventor and lead maintainer.
TL;DR
Start with one useful capability and a supported SDK, then prove the server through an inspector or real host before adding breadth.
What you'll read
A working server walkthrough and the minimum concepts needed to expose tools without hand-rolling the protocol.
07
MCP tools specification ↗
Justin Spahr-Summers
MCP co-inventor and lead maintainer emeritus.
TL;DR
Tool schemas describe inputs and outputs, but the client still owns consent, presentation and safety around invocation.
What you'll read
Discovery and call methods, schema contracts, structured output, errors, annotations and the user-interaction principles around tools.
08
MCP authorization ↗
David Soria Parra
MCP co-inventor and lead maintainer.
TL;DR
Remote MCP authorization builds on OAuth while keeping resource servers, authorization servers, clients and protected resources explicit.
What you'll read
Discovery, metadata, audience binding, protected-resource behavior and the flow a conforming remote client should follow.
09
MCP authorization security considerations ↗
David Soria Parra
MCP co-inventor and lead maintainer.
TL;DR
Token passthrough, confused deputies, open redirects and excessive scopes turn a convenient connector into an account-compromise path.
What you'll read
Concrete attack classes and mitigations for audience validation, consent, redirect handling, least privilege and secure token use.
10
MCP client best practices ↗
Justin Spahr-Summers
MCP co-inventor and lead maintainer emeritus.
TL;DR
Clients must treat servers as untrusted capability providers, preserve user control and make tool state and failures understandable.
What you'll read
Operational guidance for permissions, confirmations, capability changes, errors, timeouts, cancellation and safe user experience.

Reading path 3

Learn from the maintainers

The spec tells you what MCP is. The roadmap, registry and governance posts explain why it changes and who is accountable for that change.

11
MCP's first anniversary ↗
David Soria Parra
MCP co-inventor and lead maintainer.
TL;DR
MCP's first year moved the protocol from an Anthropic launch to broad infrastructure with a community process and a much larger compatibility burden.
What you'll read
A maintainer retrospective on adoption, specification evolution, ecosystem growth and the problems still unsolved after year one.
12
Introducing the MCP Registry ↗
David Soria Parra
MCP co-inventor and lead maintainer.
TL;DR
A shared registry standardizes discovery metadata; it does not certify server quality, safety, uptime or real tool execution.
What you'll read
Why the registry exists, how publishers and aggregators interact with it, and what canonical metadata can and cannot prove.
13
Governance and stewardship ↗
Justin Spahr-Summers
MCP co-inventor and lead maintainer emeritus.
TL;DR
MCP uses named maintainers, decision roles and public processes rather than letting protocol direction hide inside one vendor's product roadmap.
What you'll read
Maintainer roles, decision authority, working groups, escalation and the public structure behind specification changes.
14
The MCP roadmap ↗
David Soria Parra
MCP co-inventor and lead maintainer.
TL;DR
The roadmap identifies the protocol's active pressure points so builders can avoid treating current gaps as permanent architecture.
What you'll read
Maintainer priorities across transport, authorization, discovery, enterprise use, agents and extension mechanisms.
15
MCP joins the Agentic AI Foundation ↗
Anthropic
Builder of Claude, MCP and Claude Managed Agents.
TL;DR
Moving stewardship into a neutral foundation makes MCP less dependent on Anthropic while creating a formal home for ecosystem governance.
What you'll read
The institutional transition, founding projects and what neutral stewardship changes—and does not change—for implementers.