agui-dotnet-streaming-chat

Getting started with AG-UI .NET — streaming chat

Goal: install the packages, stand up an AG-UI endpoint, connect a client, and stream a multi-turn conversation. You are done when you run the client and it prints a streamed reply.

The two agent types (read this first)

How you keep a conversation going depends on who owns the history:

• Stateless agent (the default). The server keeps nothing between turns — it is a pure function of the request. The client owns the history and resends the full message list every turn. This is where you start.
• Hosted / conversation-holding agent. A server (or runtime) persists the conversation in a session keyed by the thread id, so it can recall history. The client sends the new turn under a stable thread id. Covered below.

AGUIChatClient is a Microsoft.Extensions.AI.IChatClient, so you consume it with the ordinary GetStreamingResponseAsync(messages, options, ct) API.

Thread id. Every conversation has one — it is the stable identifier for the whole exchange. Keep it stable across turns by reusing the same ChatOptions instance: AGUIChatClient pins the resolved thread id onto it after the first turn. (The SDK never surfaces it as ConversationId — update.ConversationId is always null by design, issue #4869 — so don't use ConversationId to track a conversation.)

Install the packages

Client app:

dotnet add package AGUI.Client

Server app:

dotnet add package AGUI.Server      # RunAgentInput adaptation + event-stream conversion
dotnet add package AGUI.Formatting  # SseEventStreamFormatter (writes the SSE wire format)

dotnet add package installs the latest stable version. To discover versions or pin one:

dotnet package search AGUI.Client --exact-match   # show the latest version on nuget.org
dotnet add package AGUI.Client --prerelease        # install latest, including prereleases
dotnet add package AGUI.Client --version <x.y.z>   # pin a specific version