I run a production remote MCP Server that generates invoice PDFs for agents and hat to migrate it for the jul 28th spec release--the largest revision since MCP launch: protocol session and the MCPSessionId header are removed, new mcp-* headers become mandatory, erro codes change, and sampling/logging/roots are deprecated.This gude is the writeup I wish existed when I started. It shows what breaks, why, and the exact migration step for each. The short version: If your server keys any state on session IDs it breaks at the cutover. Move state into explicit handles passed as tool arguments.My own server is the test bed. Everthing in the guide is verified against a live deployement . Happy to answer migration questions.