MCP Gets a Formal Deprecation Policy — Roots, Sampling, Logging, and HTTP+SSE All Start a 12-Month Clock
Model Context Protocol Blog·medium signal
For the first time MCP defines Active / Deprecated / Removed lifecycles with a minimum 12-month deprecation window (SEP-2577 for Roots, Sampling, and Logging; SEP-2596 for the HTTP+SSE transport). Anything deprecated in the 2026-07-28 revision stays in the spec until at least July 2027, and expedited removal requires 90 days' notice. If your server leans on Sampling to call back into the client's model, you now have a dated migration deadline rather than an open-ended one.