modelcontextprotocol/csharp-sdk

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

4,521

stars

785

commits

C#

primary language

Sep 11, 2026

updated

csharp.sdk.modelcontextprotocol.io/
csharp
dotnet
mcp
mcp-client
mcp-server
modelcontextprotocol
Browse cluster: Model Context Protocol (MCP) SDKs

README

MCP C# SDK

NuGet version

The official C# SDK for the Model Context Protocol, enabling .NET applications, services, and libraries to implement and interact with MCP clients and servers. Please visit the API documentation for more details on available functionality.

Packages

The SDK packages are:

  • ModelContextProtocol.Core NuGet version - For projects that only need to use the client or low-level server APIs and want the minimum number of dependencies.

  • ModelContextProtocol NuGet version - The main package with hosting and dependency injection extensions. References ModelContextProtocol.Core. This is the right fit for most projects that don't need HTTP server capabilities.

  • ModelContextProtocol.AspNetCore NuGet version - The library for HTTP-based MCP servers. References ModelContextProtocol.

  • ModelContextProtocol.Extensions.Apps NuGet version - MCP Apps extension for building interactive UI applications that render inside MCP hosts.

  • ModelContextProtocol.Extensions.Tasks NuGet version - MCP Tasks extension for running long-running tool invocations asynchronously with status polling and input requests.

Getting Started

To get started, see the Getting Started guide in the conceptual documentation for installation instructions, package-selection guidance, and complete examples for both clients and servers.

You can also browse the samples directory and the API documentation for more details on available functionality.

About MCP

The Model Context Protocol (MCP) is an open protocol that standardizes how applications provide context to Large Language Models (LLMs). It enables secure integration between LLMs and various data sources and tools.

For more information about MCP:

Cross-Application Access (Identity Assertion Authorization Grant flow)

The SDK provides support for the Identity Assertion Authorization Grant flow via IdentityAssertionGrantProvider. See the Cross-Application Access section in the transport docs for full usage details.

License

This project is licensed under the Apache License 2.0.

Contributors

(top 30 of 86)

Copilot

152 commits

stephentoub

121 commits

dependabot[bot]

100 commits

halter73

91 commits

modelcontextprotocol/csharp-sdk

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

4,521

stars

785

commits

C#

primary language

Sep 11, 2026

updated

csharp.sdk.modelcontextprotocol.io/
csharp
dotnet
mcp
mcp-client
mcp-server
modelcontextprotocol
Browse cluster: Model Context Protocol (MCP) SDKs

README

MCP C# SDK

NuGet version

The official C# SDK for the Model Context Protocol, enabling .NET applications, services, and libraries to implement and interact with MCP clients and servers. Please visit the API documentation for more details on available functionality.

Packages

The SDK packages are:

  • ModelContextProtocol.Core NuGet version - For projects that only need to use the client or low-level server APIs and want the minimum number of dependencies.

  • ModelContextProtocol NuGet version - The main package with hosting and dependency injection extensions. References ModelContextProtocol.Core. This is the right fit for most projects that don't need HTTP server capabilities.

  • ModelContextProtocol.AspNetCore NuGet version - The library for HTTP-based MCP servers. References ModelContextProtocol.

  • ModelContextProtocol.Extensions.Apps NuGet version - MCP Apps extension for building interactive UI applications that render inside MCP hosts.

  • ModelContextProtocol.Extensions.Tasks NuGet version - MCP Tasks extension for running long-running tool invocations asynchronously with status polling and input requests.

Getting Started

To get started, see the Getting Started guide in the conceptual documentation for installation instructions, package-selection guidance, and complete examples for both clients and servers.

You can also browse the samples directory and the API documentation for more details on available functionality.

About MCP

The Model Context Protocol (MCP) is an open protocol that standardizes how applications provide context to Large Language Models (LLMs). It enables secure integration between LLMs and various data sources and tools.

For more information about MCP:

Cross-Application Access (Identity Assertion Authorization Grant flow)

The SDK provides support for the Identity Assertion Authorization Grant flow via IdentityAssertionGrantProvider. See the Cross-Application Access section in the transport docs for full usage details.

License

This project is licensed under the Apache License 2.0.

Contributors

(top 30 of 86)

Copilot

152 commits

stephentoub

121 commits

dependabot[bot]

100 commits

halter73

91 commits

Languages

C#

99.8%