--- title: Announcing v2.0 of the official MCP C# SDK | daily.dev description: MCP C# SDK v2.0 implements the 2026-07-28 MCP specification, the largest protocol revision since launch. Key changes include stateless-by-default HTTP... canonical: https://daily.dev/posts/announcing-v2-0-of-the-official-mcp-c-sdk-m9sxlnn8t twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Announcing v2.0 of the official MCP C# SDK | daily.dev og:description: MCP C# SDK v2.0 implements the 2026-07-28 MCP specification, the largest protocol revision since launch. Key changes include stateless-by-default HTTP... og:url: https://daily.dev/posts/announcing-v2-0-of-the-official-mcp-c-sdk-m9sxlnn8t og:image: https://api.daily.dev/og/posts/M9sxLnn8T.png og:image:alt: Announcing v2.0 of the official MCP C# SDK og:image:width: 1200 og:image:height: 630 og:locale: en --- [.NET Blog](https://daily.dev/sources/dotnet) [Read post](https://api.daily.dev/r/M9sxLnn8T) # [Announcing v2.0 of the official MCP C# SDK](https://api.daily.dev/r/M9sxLnn8T "Go to post") MCP C# SDK v2.0 implements the 2026-07-28 MCP specification, the largest protocol revision since launch. Key changes include stateless-by-default HTTP transport (eliminating sticky sessions and enabling horizontal scaling), standardized HTTP headers (Mcp-Method, Mcp-Name, Mcp-Param-\*) for routing MCP traffic without body inspection, and Multi Round-Trip Requests (MRTR) that allow interactive tools to request user input without persistent sessions. MRTR replaces the old server-initiated elicitation, sampling, and roots patterns. The release is backward compatible — v1 code continues to compile, old clients/servers still work, and deprecated APIs emit warnings rather than errors. The SDK targets net8.0, net9.0, net10.0, and netstandard2.0, and ships as composable NuGet packages. Extensions for long-running Tasks and server-delivered Apps are opt-in separate packages. Next focus is end-to-end authentication and authorization. [#.net](/tags/.net "Check all #.net posts")[#c#](/tags/c%23 "Check all #c# posts")[#mcp](/tags/mcp "Check all #mcp posts")[#aspnet](/tags/aspnet "Check all #aspnet posts") Jul 28•18m read time•From [devblogs.microsoft.com](https://api.daily.dev/r/M9sxLnn8T "devblogs.microsoft.com") [](https://api.daily.dev/r/M9sxLnn8T "Go to post") Table of contents [Stateless by default Copy link](https://api.daily.dev/r/M9sxLnn8T?a=stateless-by-default "Stateless by default Copy link")[Built to scale on plain HTTP Copy link](https://api.daily.dev/r/M9sxLnn8T?a=built-to-scale-on-plain-http "Built to scale on plain HTTP Copy link")[Requesting user input Copy link](https://api.daily.dev/r/M9sxLnn8T?a=requesting-user-input "Requesting user input Copy link")[Backward compatible by design Copy link](https://api.daily.dev/r/M9sxLnn8T?a=backward-compatible-by-design "Backward compatible by design Copy link")[Packages and target frameworks Copy link](https://api.daily.dev/r/M9sxLnn8T?a=packages-and-target-frameworks "Packages and target frameworks Copy link")[Extensions: Apps and Tasks Copy link](https://api.daily.dev/r/M9sxLnn8T?a=extensions:-apps-and-tasks "Extensions: Apps and Tasks Copy link")[What’s next Copy link](https://api.daily.dev/r/M9sxLnn8T?a=what’s-next "What’s next Copy link")[Summary Copy link](https://api.daily.dev/r/M9sxLnn8T?a=summary "Summary Copy link") 17 Impressions Comment Bookmark Copy Share your thoughtsPost [](https://daily.dev/sources/dotnet) [.NET Blog](https://daily.dev/sources/dotnet "https://daily.dev/sources/dotnet") dotnet offers insights into .NET development, C# programming language, and cross-platform applicatio... 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