SEP-2596: Specification Feature Lifecycle and Deprecation Policy - #2596
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Requires any named replacement to already be Active when the deprecation lands (not just at removal time), adds an SDK-side deprecation-marking expectation, and rewrites the Tier-1 SDK removal gate to say "users can complete the migration" rather than the ambiguous "no longer required for protocol conformance." Also drops the angle-bracket email from the Author line, which was breaking MDX generation. :house: Remote-Dev: homespace
Anchors every clock to a knowable date (deprecation SEP reaching Final and revisions being "released as Current") so the twelve-month and ninety-day floors can be computed without guessing a future publication date. Points all decision steps at the governance Decision Process section rather than SEP-932, which has no such section. Reframes §Transition as an explicit grandfathering clause for the two pre-existing deprecations, with their migration targets recorded so the removal procedure has something to check. Also: replacements must be Active in a Current revision (not just draft), expedited shortening can be approved post-Final via the removal SEP, the §Roles table now covers restoration and the SDK waiver, the states table uses capital-C Current consistently, RFC 2026 swapped for RFC 8996, and the Reference Implementation no longer promises schema.ts tags for transport types that do not exist. :house: Remote-Dev: homespace
…cycle-and-deprecation # Conflicts: # docs/docs.json # docs/seps/index.mdx :house: Remote-Dev: homespace
States explicitly that a feature is Deprecated from the moment its SEP reaches Final rather than waiting for the next spec revision, and explains why a feature may remain Deprecated indefinitely. Points the roots/sampling motivation bullet at SEP-2577 instead of meeting notes, notes Lead Maintainer veto in the Roles table, and switches three British spellings to American. :house: Remote-Dev: homespace
localden
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April 24, 2026 18:15
CaitieM20
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Apr 24, 2026
…tifacts Adds an explicit Relocating-to-extension subsection for low-usage features moving out of core (the SEP-2577 case), and replaces the undefined "stable, generally available release" bar with the concrete SEP-2133 artifacts a sponsor can check: Extensions Track SEP at Final and publication in an ext-* (not experimental-ext-*) repository. Also fixes the includeContext reference-implementation note (it is a string union, not an enum) and removes section-sign prefixes from cross-references. :house: Remote-Dev: homespace
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Co-authored-by: Paul Carleton <paulcarletonjr@gmail.com>
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This was referenced Aug 10, 2026
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Establishes a formal lifecycle for individual features within the MCP specification (Active, Deprecated, Removed), with a minimum twelve-month window between deprecation and earliest removal, required
@deprecatedschema annotations and changelog entries, and a two-SEP procedure where deprecation and removal are each their own proposal.This is the mechanics follow-up to the direction recorded in the April 1, 2026 Core Maintainer meeting ("formal versioning status and SDK deprecation cycle: direction agreed, mechanics TBD") and the support-window model floated at the NYC maintainer meeting. It reclassifies the two existing informal deprecations (the HTTP+SSE transport and the
includeContextvaluesthisServer/allServers) under the new policy and notes its relationship to SEP-1400 (semantic versioning) as complementary rather than overlapping.