GroupChatManager.UpdateHistoryAsync Method
Definition
Important
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Filters the messages broadcast to participants for the current turn.
protected internal virtual System.Threading.Tasks.ValueTask<System.Collections.Generic.IEnumerable<Microsoft.Extensions.AI.ChatMessage>> UpdateHistoryAsync(System.Collections.Generic.IReadOnlyList<Microsoft.Extensions.AI.ChatMessage> history, System.Threading.CancellationToken cancellationToken = default);abstract member UpdateHistoryAsync : System.Collections.Generic.IReadOnlyList<Microsoft.Extensions.AI.ChatMessage> * System.Threading.CancellationToken -> System.Threading.Tasks.ValueTask<seq<Microsoft.Extensions.AI.ChatMessage>>
override this.UpdateHistoryAsync : System.Collections.Generic.IReadOnlyList<Microsoft.Extensions.AI.ChatMessage> * System.Threading.CancellationToken -> System.Threading.Tasks.ValueTask<seq<Microsoft.Extensions.AI.ChatMessage>>Protected Friend Overridable Function UpdateHistoryAsync (history As IReadOnlyList(Of ChatMessage), Optional cancellationToken As CancellationToken = Nothing) As ValueTask(Of IEnumerable(Of ChatMessage))Parameters
- history
- IReadOnlyList<ChatMessage>
The new messages about to be broadcast to participants this turn.
- cancellationToken
- CancellationToken
The CancellationToken to monitor for cancellation requests. The default is None.
Returns
The filtered message list to broadcast.
Remarks
Under the broadcast model, each participant maintains its own per-agent session (history) through its Microsoft.Agents.AI.Workflows.Specialized.AIAgentHostExecutor. The host distributes new messages (initial user input on the first turn, the most recent speaker's response on subsequent turns) to every participant — except the speaker that produced them — so every participant's session stays synchronized. This method lets the manager shape that broadcast payload (for example, to omit certain messages or to inject orchestrator-visible annotations). The full canonical conversation is still available to SelectNextAgentAsync(IReadOnlyList<ChatMessage>, CancellationToken) and ShouldTerminateAsync(IReadOnlyList<ChatMessage>, CancellationToken).