Agent Orchestration

As a multi-agent system grows larger, the need grows for a clearer management layer that determines what gets done, in what order, and by which agent. That responsibility falls to the orchestrator.

What Is Orchestration?

Orchestration means coordinating the execution of several agents to reach a shared goal — a concept similar to an orchestra conductor scheduling which musician plays when. Unlike architecture patterns, which describe the communication structure, orchestration is about the behavior and decision logic of that management layer.

The Orchestrator's Core Responsibilities

Task Decomposition

The first step is breaking a user's complex request into smaller, well-defined sub-tasks. For example, "buy me the best phone under $500" gets split into sub-tasks like "search phones in this price range," "check each one's stock," and "complete the purchase of the selected option."

Routing

For each sub-task, the orchestrator has to decide which agent (or which tool) is responsible for it. This decision can be rule-based (deterministic routing) or made by a language model itself (smart/dynamic routing).

Result Aggregation

When several agents return separate results, the orchestrator has to turn them into one coherent, final answer for the user — including resolving any potential conflict between results (e.g. if two agents give contradictory stock information).

Error Handling

If a sub-agent fails or doesn't respond, the orchestrator has to decide: retry, fall back to an alternate agent, or clearly inform the user that part of the request couldn't be fulfilled — instead of a complete, silent failure of the whole process.

Observability, Tracing & Human-in-the-loop

When the routing decision is delegated to a language model (instead of fixed, predictable rules), the system's behavior is no longer fully deterministic — which is why a real-world orchestrator needs two additional layers beyond pure routing logic:

• Tracing — a complete record of every orchestrator decision: which sub-task was delegated to which agent, what input/output was exchanged, and how long it took. Without this tracing, finding the root cause of a wrong answer in a multi-agent system is practically impossible.
• Human-in-the-loop — for sensitive sub-tasks (like large financial transactions), the orchestrator can deliberately pause before execution and wait for human approval; this pattern is implemented in frameworks like LangGraph via checkpointing.

Common Implementation Tools

LangGraph is one of the most common tools for implementing orchestration logic, since its shared State and conditional branches cover exactly this need. For communicating with agents outside the organization, the orchestration layer usually uses the A2A protocol.

FAQ