# Microsoft releases .NET SDK for AG-UI agent-user interaction protocol

> Source: <https://www.infoworld.com/article/4227233/microsoft-releases-net-sdk-for-ag-ui-agent-user-interaction-protocol.html>
> Published: 2026-09-27 15:52:47+00:00

Microsoft on [September 25 announced](https://devblogs.microsoft.com/dotnet/ag-ui-dotnet-sdk/) a .NET SDK for AG-UI (Agent-User Interaction). Created in collaboration with [CopilotKit](https://www.copilotkit.ai/), the new SDK allows C# developers to work with the protocol that standardizes how agents communicate with user-facing applications.

The .NET SDK for AG-UI lives in the [AG-UI repository](https://github.com/ag-ui-protocol/ag-ui/tree/main/sdks/dotnet) alongside the [TypeScript](https://www.infoworld.com/article/2257305/what-is-typescript-strongly-typed-javascript.html) and [Python](https://www.infoworld.com/article/4020500/python-powered-ai-agents-are-here.html) SDKs, and is published on NuGet under the MIT license. Its C# implementation of AG-UI is usable from any .NET service, Microsoft said. AG-UI support for .NET in the Microsoft Agent Framework (MAF) is now based on the .NET SDK for AG-UI, the company added.

AG-UI is an event-based protocol that allows AI agents to interact with front-end applications. A back end emits AG-UI events natively, and a client consumes them from an agent written in any supported language. The protocol includes events in eight different categories, according to the [documentation](https://docs.ag-ui.com/concepts/events): 

The .NET SDK for AG-UI works in both directions, Microsoft said. `AGUI.Server` turns an agent into an AG-UI endpoint and `AGUI.Client` enables a .NET application to consume an AG-UI endpoint.`AGUI.Server` and `AGUI.Client` are built on a common set of AG-UI primitives. 

The .NET SDK for AG-UI ships as [five packages on NuGet](https://www.nuget.org/packages/AGUI.Abstractions): 

`AGUI.Abstractions` — protocol events, messages, tools, capabilities, and JSON serialization. `AGUI.Formatting` — event stream formatter abstractions and Server-Sent Events support. `AGUI.Protobuf` — protobuf codec and binary event stream formatting. `AGUI.Client` — AG-UI HTTP client and `IChatClient` integration. `AGUI.Server` — server-side adapter from `ChatResponseUpdate` streams to AG-UI events.
Microsoft offered the following links for getting started:

The company welcomes questions and feedback about the SDK in the [AG-UI repository](https://github.com/ag-ui-protocol/ag-ui). It asks that questions about Microsoft Agent Framework integration be directed to the [Microsoft Agent Framework discussion boards](https://github.com/microsoft/agent-framework/discussions).