Agent Orchestration - how to provide chat history?

[adrianzailic]

Hello,

Is there any way to pass the previous chat history to the Agent Orchestration when invoking it?

My use case is that I have a REST API with a chat completion endpoint that uses the Semantic Kernel Agent Orchestration to reply to the user’s prompt. The problem is that I want to support scenarios where the task is spread across multiple prompts, as in the example below:

User: What transactions do we have about X?
Assistant: The Data Retrieval agent replies with a list of transactions.
User: Tell me more about the second one.

In this scenario, the chat history is crucial. It would be stored in the frontend app and sent with each request to my chat completion endpoint.

I would have a list of agents and would like to use the Handoff Orchestration to route the prompt to the correct agent. However, it seems there is no way to provide the entire chat history within an orchestration:

string task = "Tell me more about the second one.";
var result = await orchestration.InvokeAsync(task, runtime);

Here I can only provide a single string, not the entire chat history.

I tried creating a longer prompt that includes both the chat history and the current user prompt, like this:

Based on the previous conversation {list of conversations}, answer the current request/prompt: {task}

But this approach is never as effective as providing the actual chat history.

On the other hand, if I do the triage separately in a chat completion call and then invoke the selected agent directly, I can pass the entire chat history:

selectedAgent.InvokeAsync(chatHistory, cancellationToken)

Could you please help me understand if this is possible within an orchestration, or if it’s not yet supported by the framework?

[KuCoolCan]

Si lo pudieras traducir al español con gusto te resuelvo El mié, 3 de sept de 2025 07:28, Adrian Zailic ***@***.***> escribió:

…

Hello, Is there any way to pass the previous chat history to the Agent Orchestration when invoking it? My use case is that I have a REST API with a chat completion endpoint that uses the Semantic Kernel Agent Orchestration to reply to the user’s prompt. The problem is that I want to support scenarios where the task is spread across multiple prompts, as in the example below: User: What transactions do we have about X? Assistant: The Data Retrieval agent replies with a list of transactions. User: Tell me more about the second one. In this scenario, the chat history is crucial. It would be stored in the frontend app and sent with each request to my chat completion endpoint. I would have a list of agents and would like to use the Handoff Orchestration to route the prompt to the correct agent. However, it seems there is no way to provide the entire chat history within an orchestration: string task = "Tell me more about the second one."; var result = await orchestration.InvokeAsync(task, runtime); Here I can only provide a single string, not the entire chat history. I tried creating a longer prompt that includes both the chat history and the current user prompt, like this: *Based on the previous conversation {list of conversations}, answer the current request/prompt: {task}* But this approach is never as effective as providing the actual chat history. On the other hand, if I do the triage separately in a chat completion call and then invoke the selected agent directly, I can pass the entire chat history: selectedAgent.InvokeAsync(chatHistory, cancellationToken) Could you please help me understand if this is possible within an orchestration, or if it’s not yet supported by the framework? — Reply to this email directly, view it on GitHub <#13059>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A6UAQV7WXKN6XZXI4IG5DRL3Q3UHFAVCNFSM6AAAAACFQT3U3GVHI2DSMVQWIX3LMV43ERDJONRXK43TNFXW4OZYHAZTKNZVHE> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[justinbarias]

You gotta provide a callback and build it yourself:

ChatHistory history = [];

ValueTask responseCallback(ChatMessageContent response)
{
    history.Add(response);
    return ValueTask.CompletedTask;
}

Then, instanciate your orchestrator:

MagenticOrchestration orchestration = new MagenticOrchestration(
    manager,
    researchAgent,
    coderAgent)
{
    ResponseCallback = responseCallback,
};

That will populate the chat history you provide.

[adrianzailic]

I already tried this, but it’s not working as expected. Even though I can see all the previous messages in the history object when the callback is invoked (triggered by an agent response), the final message is completely wrong. It seems that the history is not being passed when the call to the LLM is made.

There’s a night-and-day difference compared to calling an agent directly, where the chat history is passed in agent.InvokeAsync(chatHistory). In that case, the responses are clearly based on the entire chat history.