Issues

• stdio client never closes the server's stdin, so every client dispose burns the full ShutdownTimeout (5s by default)

  modelcontextprotocol/csharp-sdk#1836 · Filter by author FrancescoCrecchi opened on Aug 25, 2026
  1

• 2.2.0: binary content blocks (ImageContentBlock, BlobResourceContents) serialize invalid base64 - client-side CallToolResult deserialization throws (regression of #1340)

  modelcontextprotocol/csharp-sdk#1835 · Filter by author marcfreiheit opened on Aug 25, 2026
  1

• Interactive OAuth flow is aborted by DiscoverProbeTimeout during dual-path connect, then fails with an authorization state mismatch

  area-authbugP2
  modelcontextprotocol/csharp-sdk#1830 · Filter by author PederHP opened on Aug 20, 2026 · 2.x
  2

  

• Add a stable server-side MCP Task execution extension point

  enhancementP2ready for work
  modelcontextprotocol/csharp-sdk#1820 · Filter by author cecilphillip opened on Aug 16, 2026
  5

• Support the OAuth 2.0 Device Authorization Grant (RFC 8628) for headless clients

  area-authenhancement
  modelcontextprotocol/csharp-sdk#1811 · Filter by author Aaronontheweb opened on Aug 11, 2026
  1

• Flaky on windows-latest: OAuth metadata fetch times out in in-memory tests (same class as #1701, not covered by #1702)

  area-testsbughelp wantedP3ready for work
  modelcontextprotocol/csharp-sdk#1806 · Filter by author AkbarDizaji opened on Aug 9, 2026 · 2.x
  6

• Tool Call Failed: Request timed out

  bughelp wantedneeds reproP3
  modelcontextprotocol/csharp-sdk#1785 · Filter by author khteh opened on Aug 3, 2026 · 2.x
  9

• Streaming HTTP MCP server integration tests

  documentationhelp wantedP3ready for work
  modelcontextprotocol/csharp-sdk#1781 · Filter by author khteh opened on Aug 2, 2026 · 2.x
  1

• Wire up the three new auth conformance scenarios from

  area-authenhancementP3ready for work
  modelcontextprotocol/csharp-sdk#1770 · Filter by author AkbarDizaji opened on Jul 29, 2026 · 2.x
  2

  

• Bad Request of "Missing Session Id" from a stateful MCP server

  needs repro
  modelcontextprotocol/csharp-sdk#1759 · Filter by author jzhouw opened on Jul 28, 2026
  3

• Define handling for protocol-incompatible result properties set by applications

  enhancementP2ready for work
  modelcontextprotocol/csharp-sdk#1754 · Filter by author halter73 opened on Jul 27, 2026 · 2.x
  1

• Document the Windows cmd.exe /c interposition as a security-relevant property, not just a quoting bug

  documentationenhancementP2ready for work
  modelcontextprotocol/csharp-sdk#1751 · Filter by author anorboev opened on Jul 27, 2026 · 2.x
  2

  

• Provide extensions for calling McpClientTools as tasks

  enhancementP3ready for work
  modelcontextprotocol/csharp-sdk#1730 · Filter by author KubaZ2 opened on Jul 24, 2026 · 2.x
  3

• Deterministically cancel background task-store runners on server disposal via a server-lifetime CTS

  bugenhancementP2ready for work
  modelcontextprotocol/csharp-sdk#1707 · Filter by author PranavSenthilnathan opened on Jul 16, 2026 · 2.x
  1

  

• Make server extension handlers composable with filters and subscriptions

  enhancementP2ready for work
  modelcontextprotocol/csharp-sdk#1704 · Filter by author halter73 opened on Jul 14, 2026 · 2.x
  4

  

• Flaky test host hang on Windows Debug CI: TaskCancellationIntegrationTests.TaskTool_CancellationToken_GetTaskShowsWorkingBeforeCancel

  area-testsbugP3ready for work
  modelcontextprotocol/csharp-sdk#1701 · Filter by author PranavSenthilnathan opened on Jul 13, 2026 · 2.x
  2

• Add prior-knowledge connection path for modern protocol clients

  enhancementneeds confirmationP2
  modelcontextprotocol/csharp-sdk#1696 · Filter by author halter73 opened on Jul 8, 2026 · 2.x

• Optional exception summarization for server-side logging

  enhancementP3ready for work
  modelcontextprotocol/csharp-sdk#1690 · Filter by author crhaglun opened on Jul 6, 2026 · 2.x
  4

• Tool annotation default values are not applied

  bugneeds confirmationP3
  modelcontextprotocol/csharp-sdk#1673 · Filter by author Kumima opened on Jun 27, 2026 · 2.x
  1

• Conformance Track B: stateful HTTP/stdio modes, SEP-2549 absence-assert, remaining MRTR scenarios

  area-testsenhancementP2
  modelcontextprotocol/csharp-sdk#1653 · Filter by author halter73 opened on Jun 16, 2026 · 2026-07-28 Spec Compliance
  

• MCP Apps: Add [McpAppResource] attribute and resource-collection processing in WithMcpApps()

  enhancementP3ready for work
  modelcontextprotocol/csharp-sdk#1636 · Filter by author mikekistler opened on Jun 9, 2026 · 2.x
  1

• Restore [McpServerTool] composability with MRTR input requests + tasks

  enhancementP2ready for work
  modelcontextprotocol/csharp-sdk#1635 · Filter by author halter73 opened on Jun 8, 2026 · 2.x
  1

• Identity Assertion Grant flow only supports OIDC ID tokens, not SAML 2.0 assertions

  area-authenhancementP3ready for work
  modelcontextprotocol/csharp-sdk#1618 · Filter by author halter73 opened on Jun 1, 2026 · 2.x
  1

• Identity Assertion Grant uses raw authorization server URL as token-exchange audience

  area-authbugP2
  modelcontextprotocol/csharp-sdk#1617 · Filter by author halter73 opened on Jun 1, 2026 · 2.x
  

• Can't implement a CIMD client if auth provider doesn't put "none" first in it's list of supported token auth methods

  area-authbugP2
  modelcontextprotocol/csharp-sdk#1612 · Filter by author mikeholczer opened on May 29, 2026 · 2.x
  1