Multi-Agent Workflows

Multi-agent workflows let multiple agents work together in a directed graph. Each agent handles one step and passes its output to the next. Use this when a task is too complex for a single agent, or when you want specialized agents for different parts of a pipeline.

Input
  │
  ▼
┌──────────┐     ┌──────────┐     ┌──────────┐
│ Triage   │────►│ Research │────►│ Writer   │
│ Agent    │     │ Agent    │     │ Agent    │
└──────────┘     └──────────┘     └──────────┘
                                       │
                                       ▼
                                    Output

When to Use Multi-Agent vs SubAgent

	SubAgent	Multi-Agent Workflow
Agents	One child agent	Many agents in a graph
Structure	Simple delegation	Directed pipeline or graph
Routing	None	Conditional edges, handoffs
Use when	One specialized task	Sequential or parallel pipeline

→ See 02.1.3 SubAgents.md for single agent delegation.

Quick Start

using HPD.MultiAgent;

var workflow = await AgentWorkflow.Create()
    .AddAgent("researcher", new AgentConfig
    {
        SystemInstructions = "Research the topic thoroughly."
    })
    .AddAgent("writer", new AgentConfig
    {
        SystemInstructions = "Write a clear, concise answer."
    })
    .From("researcher").To("writer")
    .BuildAsync();

var result = await workflow.RunAsync("Explain quantum entanglement");
Console.WriteLine(result.FinalAnswer);

Streaming

await foreach (var evt in workflow.ExecuteStreamingAsync(input))
{
    if (evt is TextDeltaEvent delta)
        Console.Write(delta.Text);
    if (evt is WorkflowCompletedEvent)
        Console.WriteLine("\nDone.");
}

In This Section

• 06.2 Building Workflows — fluent builder, adding agents, edges, JSON config, iteration options
• 06.3 Node Options — timeout, retry, concurrency, output modes, input/output keys, approval
• 06.4 Routing & Edges — conditional edges, router agents, type-based routing
• 06.5 As a Toolkit Capability — exposing workflows as tools with [MultiAgent]
• 06.6 Workflow Events — full event reference, streaming patterns, event order
• 06.7 Observability — MetricsObserver, TracingObserver, OpenTelemetry integration