Composable workflows?

[jooooel]

Hi,
I'm trying to build a composable workflow in a way.

My idea is to have an initial triage agent, that just hands off the work to someone with a matching description. I've got that working fine when someone is a ChatClientAgent.

But I would like to find a way of that someone being a workflow.
For example. The triage agent can choose to hand off the work to simpleAgent which is just a ChatClientAgent, or it could hand off to workflowAgent which is a workflow exposed as an agent (AsAgent()). Ideally, I don't want the triage agent to know if it's an agent or a workflow, it should just hand off to the one that matches the description.

But I haven't gotten it to work. I'm getting an exception like this from the Workflow agent System.InvalidOperationException: Workflow does not support ChatProtocol: At least List<ChatMessage> and TurnToken must be supported as input.

I don't know if this is enough info, or if I need to create a repro to show it. But is there a way of getting this to work?

var workflow = AgentWorkflowBuilder.CreateHandoffBuilderWith(triageAgent)
    .WithHandoffs(triageAgent, [simpleAgent, workflowAgent])
    .Build();

chatMessages.Add(new(ChatRole.User, query));

var run = await InProcessExecution.StreamAsync(workflow, chatMessages);
await run.TrySendMessageAsync(new TurnToken(emitEvents: true));

await foreach (var evt in run.WatchStreamAsync())
{
    ...

---

// This is kind of how workflowAgent is built
WorkflowBuilder builder = new(queryStartExecutor);
builder
    .AddEdge(source: queryStartExecutor, target: queryAnalysisAgent)
    .WithOutputFrom(queryAnalysisAgent)
    .Build()
    .AsAgent();

[moonbox3]

Adding @lokitoth to help.

[lokitoth]

Hi @jooooel, in order for you to use a workflow as an agent, its starting executor needs to implement the "Turn Take Chat Protocol", by supporting at least List<ChatMessage and TurnToken (and you will also need to ensure that it outputs both ChatMessages and the TurnToken that you want to feed back to the parent).

The other issue you'll encounter if you try to use it with HandoffsWorkflowBuilder is the need for the workflow to be able to use the provided tools to invoke the handoff. This is not currently supported, and it is not entirely clear how to make the tools available to the workflow / how to have the subworkflow communicate the following handoff to the parent workflow without tools. This may not be an issue if you can simply terminate once the simpleAgent / workflowAgent are done.