Quick answer
MCP 2026-07-28 marks Roots, Sampling, Logging, HTTP+SSE, two includeContext values, and OAuth Dynamic Client Registration as deprecated. Deprecated does not mean removed: the changelog says these features remain available during their transition window, but new implementations should not adopt them.
The formal lifecycle uses Active, Deprecated, and Removed states with a minimum twelve-month deprecation window.
Migration map
| Deprecated surface | Official direction |
|---|---|
| Roots | Pass directories or files through tool parameters, resource URIs, or server configuration |
| Sampling | Integrate directly with the selected LLM provider API |
| Logging | Use stderr for stdio or OpenTelemetry for structured cloud observability |
| HTTP+SSE | Migrate to Streamable HTTP |
includeContext: "thisServer" or "allServers" | Omit the field or use "none" |
| OAuth Dynamic Client Registration | Prefer Client ID Metadata Documents; retain compatibility only where authorization servers require it |
These replacements change authority and data flow. Direct provider access, explicit file parameters, and telemetry export each need their own permission and security review.
Staged migration
- Measure which deprecated features are actually in use.
- Pin the current protocol and SDK behavior.
- Design the replacement with equivalent or narrower permissions.
- Add compatibility tests for old and new clients.
- Canary one server and verify results, auth, logs, and rollback.
- Stop adding new dependencies on deprecated features.
- Remove legacy support only after the registry marks the feature removed and local traffic is clear.
Use the stateless migration guide for the broader revision and the MRTR and Tasks guide for server-to-client workflow changes.
Frequently asked questions
Are these features already removed?
No. They remain functional during deprecation, but should not be added to new implementations.
What replaces Logging?
The changelog recommends stderr for stdio and OpenTelemetry for structured cloud observability.
What replaces HTTP+SSE?
Streamable HTTP.
Official sources
Source check: August 6, 2026. Verify lifecycle state, removal dates, compatibility requirements, and SDK migration guidance before removal.