Deprecated Features - Model Context Protocol Documentation Index Fetch the complete documentation index at: /llms.txt Use this file to discover all available pages before exploring further. Skip to main content Model Context Protocol home page Version 2026-07-28 (latest) Search... ⌘ K Ask Assistant ⌘ I * Blog * GitHub Search... Navigation Deprecated Features Documentation Specification Extensions Registry SEPs Community * Specification * Key Changes * Deprecated Features * Architecture Base Protocol * Overview * Versioning and Compatibility * Message Patterns * Transports * Authorization Client Features * Roots * Sampling * Elicitation Server Features * Overview * Discovery * Prompts * Resources * Tools * Utilities * Schema Reference On this page * Deprecated * Removed Deprecated Features Copy page Copy page Copy page Copy page This page is the registry of specification features that are currently in the Deprecated state under the feature lifecycle and deprecation policy ( SEP-2596 ). A Deprecated feature remains part of the specification but is scheduled for removal: new implementations SHOULD NOT adopt it, and existing implementations SHOULD migrate before the feature’s earliest removal. The earliest removal marks when a feature becomes eligible for removal; the actual removal is a Core Maintainer decision taken during release preparation and may happen later. This registry is a derived view kept consistent with the per-feature deprecation notices and changelog entries, which are the normative records. ​ Deprecated Feature Deprecation SEP Deprecated in Migration path Earliest removal Roots SEP-2577 2026-07-28 Pass directories or files via tool parameters, resource URIs, or server configuration First revision released on or after 2027-07-28 Sampling SEP-2577 2026-07-28 Integrate directly with LLM provider APIs First revision released on or after 2027-07-28 Logging SEP-2577 2026-07-28 Log to stderr for stdio transports; use OpenTelemetry for observability First revision released on or after 2027-07-28 Dynamic Client Registration PR #2858 2026-07-28 Client ID Metadata Documents First revision released on or after 2027-07-28 includeContext: "thisServer" / "allServers" ( Sampling ) SEP-2596 2025-11-25 Omit the field or use "none" Follows Sampling ( SEP-2577 ) HTTP+SSE transport SEP-2596 2025-03-26 Streamable HTTP Three months after SEP-2596 reaches Final The HTTP+SSE transport and the includeContext values were already described as deprecated before the lifecycle policy existed; SEP-2596 reclassifies them as Deprecated under its transition provisions . ​ Removed No features have been removed under this policy yet. When a Deprecated feature is removed, its row moves to this section with a link to the changelog entry recording the removal. Was this page helpful? Yes No Key Changes Architecture github Assistant Responses are generated using AI and may contain mistakes.