modelcontextprotocol/csharp-sdk

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The official C# SDK for Model Context Protocol servers and clients. Maintained in collaboration with Microsoft.

Stars: 4.5k
Forks: 814
Open beginner issues: 1
Indexed issues: 126
Avg merge: 9d 19h
Merged PRs (30d): 4

Dominant language: C#
License: No license data
Last GitHub push: Sep 19, 2026
Latest indexed: Sep 20, 2026
Contributing guide: Contributing guide
Code of conduct: Code of conduct
Beginner labels: help wanted

Beginner friendly Everything

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126 open issues indexed

Not able to authenticate MCP Servers Open

area-auth bug needs confirmation P3

Difficulty 4/5 3-5 days Newbie friendliness 35/100

modelcontextprotocol/csharp-sdk#681 · 6 comments · 1 reaction · Opened Aug 6, 2025
Update ProtectedResourceMetadata to use IList/ISet instead of List Open

enhancement needs confirmation

Difficulty 2/5 1-3 hours Newbie friendliness 64/100

modelcontextprotocol/csharp-sdk#678 · 1 comment · Opened Aug 5, 2025
AspNetCore TestHost client transport Open

enhancement needs confirmation

Difficulty 4/5 3-5 days Newbie friendliness 42/100

modelcontextprotocol/csharp-sdk#659 · Opened Jul 30, 2025
Release signed binaries in nuget package Open

enhancement needs confirmation

Difficulty 4/5 3-5 days Newbie friendliness 45/100

modelcontextprotocol/csharp-sdk#657 · 1 reaction · Opened Jul 30, 2025
When Absolute Uri passed as McpAuthenticationOptions.ResourceMetadataUri, /.well-known/oauth-protected-resource endpoint returns 404 Open

area-auth bug help wanted needs confirmation P3

Difficulty 3/5 1-2 days Newbie friendliness 55/100

modelcontextprotocol/csharp-sdk#654 · 4 comments · Opened Jul 28, 2025
OAuth authentication request fails with MS Entra-ID Open

area-auth bug P2 ready for work

Difficulty 4/5 3-5 days Newbie friendliness 45/100

modelcontextprotocol/csharp-sdk#648 · 5 comments · 3 reactions · Opened Jul 25, 2025
Not able to customize the url '.well-known/oauth-protected-resource' behind AKS/nginx ingress Open

area-auth bug help wanted needs confirmation P3

Difficulty 4/5 3-5 days Newbie friendliness 45/100

modelcontextprotocol/csharp-sdk#643 · 7 comments · Opened Jul 23, 2025
Dictionary<string, JsonElement> overload for CallToolAsync Open

enhancement needs confirmation

Difficulty 2/5 1-3 hours Newbie friendliness 48/100

modelcontextprotocol/csharp-sdk#640 · Opened Jul 21, 2025
Cannot Configure JSON Serialization for MCPServer Open

enhancement needs confirmation

modelcontextprotocol/csharp-sdk#636 · 13 comments · 5 reactions · 2 assignees · Opened Jul 19, 2025
Allow tools to continue running when session is closed Open

enhancement needs confirmation

Difficulty 5/5 Over a week Newbie friendliness 45/100

modelcontextprotocol/csharp-sdk#623 · 1 comment · Opened Jul 14, 2025
Support for Runtime Tool Filtering and/or Multiple MCP Endpoints for Persona-Based Tool Sets in ASP.NET Core Open

enhancement needs confirmation

Difficulty 5/5 Over a week Newbie friendliness 35/100

modelcontextprotocol/csharp-sdk#612 · 10 comments · Opened Jul 11, 2025
Streamable HTTP server support under .NET Framework Open

enhancement needs confirmation P3

Difficulty 4/5 3-5 days Newbie friendliness 38/100

modelcontextprotocol/csharp-sdk#592 · 16 comments · 6 reactions · Opened Jul 7, 2025
Running ModelContextProtocol.Tests in net472 is causing VS test platform to hang Open

area-tests bug help wanted needs confirmation P3

Difficulty 4/5 3-5 days Newbie friendliness 25/100

modelcontextprotocol/csharp-sdk#587 · Opened Jul 4, 2025
Add support for multiple resources per MCP Authentication scheme Open

area-auth enhancement needs confirmation

Difficulty 5/5 Over a week Newbie friendliness 25/100

modelcontextprotocol/csharp-sdk#586 · Opened Jul 3, 2025
ModelContextProtocol.AspNetCore doesn't support .NET Standard? Open

enhancement needs confirmation

Difficulty 4/5 3-5 days Newbie friendliness 30/100

modelcontextprotocol/csharp-sdk#557 · 5 comments · Opened Jun 26, 2025
Support a non-SSE JSON-only mode similar to the TypeScript SDKs `enableJsonResponse: true` Open

enhancement needs confirmation P2 ready for work

Difficulty 4/5 3-5 days Newbie friendliness 35/100

modelcontextprotocol/csharp-sdk#545 · 5 comments · 4 reactions · Opened Jun 25, 2025
In the StreamableHttp mode MCP server, Scoped type dependencies are not properly injected into classes marked with [McpServerToolType]. Open

bug P2

Difficulty 4/5 3-5 days Newbie friendliness 48/100

modelcontextprotocol/csharp-sdk#544 · 7 comments · Opened Jun 25, 2025
Access to HttpContext within handler delegates like ListToolsHandler for authentication-aware logic Open

enhancement needs confirmation

Difficulty 5/5 Over a week Newbie friendliness 25/100

modelcontextprotocol/csharp-sdk#520 · 6 comments · 3 reactions · Opened Jun 15, 2025
`SseClientTransport.Endpoint` should be nullable when `HttpClient` is provided Open

enhancement needs confirmation P3 ready for work

Difficulty 2/5 1-3 hours Newbie friendliness 68/100

modelcontextprotocol/csharp-sdk#515 · 6 comments · 3 reactions · Opened Jun 13, 2025
Add Granular Authorization Support to SSE ServerTools Open

area-auth enhancement needs confirmation P2 ready for work

Difficulty 5/5 Over a week Newbie friendliness 35/100

modelcontextprotocol/csharp-sdk#483 · 7 comments · 4 reactions · Opened Jun 4, 2025
Resource-based authorization on tools Open

area-auth enhancement needs confirmation

Difficulty 4/5 3-5 days Newbie friendliness 35/100

modelcontextprotocol/csharp-sdk#450 · 1 reaction · Opened May 26, 2025
McpServerPrimitiveCollection needs transactions/updates Open

enhancement needs confirmation

Difficulty 3/5 1-2 days Newbie friendliness 48/100

modelcontextprotocol/csharp-sdk#433 · Opened May 18, 2025
Add SourceGenerator driven 'WithToolsFromAssembly' method Open

enhancement needs confirmation

Difficulty 4/5 3-5 days Newbie friendliness 35/100

modelcontextprotocol/csharp-sdk#317 · 6 comments · 2 reactions · Opened Apr 16, 2025
Support for dynamic tools Open

enhancement needs confirmation

Difficulty 5/5 Over a week Newbie friendliness 25/100

modelcontextprotocol/csharp-sdk#237 · 12 comments · Opened Apr 8, 2025
Pass context from request endpoint to message handler Open

enhancement needs confirmation

Difficulty 4/5 3-5 days Newbie friendliness 32/100

modelcontextprotocol/csharp-sdk#236 · 2 comments · 8 reactions · Opened Apr 8, 2025
Allow Integration with ASP.Net Core Open

enhancement needs confirmation P3

Difficulty 5/5 Over a week Newbie friendliness 35/100

modelcontextprotocol/csharp-sdk#119 · 10 comments · 5 reactions · Opened Mar 27, 2025

modelcontextprotocol/csharp-sdk

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