mcpdotnet: A .NET client protocol implementation

[PederHP]

Pre-submission Checklist

• This post follows the MCP community guidelines

What would you like to share?

I'm excited to share mcpdotnet, a .NET client implementation of the Model Context Protocol. This library aims to provide a clean, specification-compliant implementation with minimal additional abstraction, making it easy for .NET developers to integrate MCP into their applications.

What we've built:

• Full implementation of the MCP client protocol
• Support for both stdio and SSE transports
• Implementation of all MCP capabilities (Tools, Resources, Prompts, Sampling, Roots)
• Comprehensive logging support
• Clean, async-first API design
• Thorough integration testing

How we built it:
The library was developed with a focus on staying close to the protocol specification while providing a natural .NET experience. We followed patterns established by the official SDKs where possible, particularly in transport implementations. The codebase emphasizes clean architecture and thorough testing, using xUnit for both unit and integration tests.

Challenges faced:

• Implementing SSE transport without official reference implementation
• Balancing protocol compliance with idiomatic .NET patterns
• Ensuring robust error handling across different transport types

What we learned:

• The MCP specification is well-thought-out and consistent
• The protocol's transport abstraction makes it highly flexible
• Integration testing is crucial for protocol implementations

The library is now available on NuGet and GitHub. While we're still adding more documentation and examples before a 1.0 release, it's already fully functional and being used in production environments.

We welcome contributions and feedback from the community, whether it's submitting PRs, reporting issues, or suggesting improvements!

Relevant Links

https://github.com/PederHP/mcpdotnet