Release v2.2.0

[jeffhandley]

Release v2.2.0

This release adds hybrid stateful/stateless HTTP serving so legacy initialize clients and modern sessionless clients can share an endpoint, and fixes a malformed header-decoding edge case.

Release Notes

What’s Changed

• Fix McpHeaderEncoder.DecodeValue throwing on the degenerate base64 wrapper Fix McpHeaderEncoder.DecodeValue throwing on the degenerate base64 wrapper #1805 by @latent-9
• Add HttpServerSessionMode for hybrid stateful/stateless HTTP serving Add HttpServerSessionMode for hybrid stateful/stateless HTTP serving #1796 by @saicharanpardhu (co-authored by @copilot @jeffhandley)

Test Improvements

• Fix duplicated word in test comment Fix duplicated word in test comment #1809 by @latent-9

Repository Infrastructure Updates

• Enable package validation for the MCP extension packages Enable package validation for the MCP extension packages #1793 by @jeffhandley (co-authored by @copilot)
• Add a release-manager agent that orchestrates the release skills Add a release-manager agent that orchestrates the release skills #1794 by @jeffhandley (co-authored by @copilot)
• Bump Anthropic from 12.39.0 to 12.40.0 Bump Anthropic from 12.39.0 to 12.40.0 #1808
• Bump @hono/node-server from 1.19.14 to 2.1.0 in the npm_and_yarn group across 1 directory Bump @hono/node-server from 1.19.14 to 2.1.0 in the npm_and_yarn group across 1 directory #1812
• Fix dead relative link to versioning docs in bump-version skill Fix dead relative link to versioning docs in bump-version skill #1807 by @latent-9

Acknowledgements

• @latent-9 made their first contribution in Fix dead relative link to versioning docs in bump-version skill #1807
• @saicharanpardhu made their first contribution in Add HttpServerSessionMode for hybrid stateful/stateless HTTP serving #1796
• @saicharanpardhu submitted issue Support hybrid MCP server serving both stateful legacy clients and session less 2026-07-28 clients simultaneously #1777 (resolved by Add HttpServerSessionMode for hybrid stateful/stateless HTTP serving #1796)
• @jeffhandley @tarekgh @halter73 reviewed pull requests

Full Changelog: v2.1.0...v2.2.0

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API Compatibility Report

All five packages pass against baseline v2.0.0. No suppressions were generated, retained, removed, or modified.

Package	Baseline	Generated	Retained / removed	Release pack
ModelContextProtocol.Core	2.0.0	0	0 / 0	✅
ModelContextProtocol	2.0.0	0	0 / 0	✅
ModelContextProtocol.AspNetCore	2.0.0	0	0 / 0	✅
ModelContextProtocol.Extensions.Apps	2.0.0	0	0 / 0	✅
ModelContextProtocol.Extensions.Tasks	2.0.0	0	0 / 0	✅

API Diff Report

ModelContextProtocol.Core

No public API differences from v2.1.0.

ModelContextProtocol

No public API differences from v2.1.0.

ModelContextProtocol.AspNetCore

  namespace ModelContextProtocol.AspNetCore
  {
      public class HttpServerTransportOptions
      {
+         public ModelContextProtocol.AspNetCore.HttpServerSessionMode? SessionMode { get; set; }
      }
+     public sealed class HttpServerSessionMode
+     {
+         public const ModelContextProtocol.AspNetCore.HttpServerSessionMode Stateful = 1;
+         public const ModelContextProtocol.AspNetCore.HttpServerSessionMode StatefulForInitializeClients = 2;
+         public const ModelContextProtocol.AspNetCore.HttpServerSessionMode Stateless = 0;
+         public int value__;
+     }
  }

Note

This release-preparation content was generated with GitHub Copilot.