One method that suggests values as a user fills in an argument, and the context field that scopes those suggestions to what is already filled

The third server primitive and the one people misread: templates the user selects, rendered into messages that can embed a server's own resources

The primitive for data the model reads, the counterpart to tools, with URI templates for whole families and live notifications when something changes

Every shape a tool result can take: the five content types, structured output validated against a schema, and the difference between a failed tool and a failed protocol

What the model actually receives when it lists a server's tools, how the schema is built from a Go type, and why a tool's annotations cannot be trusted

A single HTTP path carries the protocol. In 2025-11-25 a session id is optional. In 2026-07-28 it is gone.

The simplest MCP transport, built by hand on both sides with no SDK, plus the stderr rule that silently breaks servers

Vector Search Without the Vector Database, Part 1

The 2025-11-25 initialize exchange, hand-rolled in Go against a real server. Later revisions dropped it from the protocol core.

Three message shapes, one error object, and a hundred and fifty lines of Go that every MCP transport is built on

The same tool built both ways: what discovery, schemas, and the callback direction actually cost

The Go SDK never prints the protocol. This post does.

A Case Study in Agent Psychology

Context has always been the hard problem. MCP forces you to solve it.

Building composable MCP servers for object storage

Building composable MCP servers for enterprise data

The complete guide to kubefwd's new features

Let your AI assistant manage cluster connections