Agent Router

What is an agent router?

An agent router is a component that examines a request or task and directs it to the most suitable agent, tool, or workflow. Routing reduces the need to expose every capability to every agent and helps specialized components receive the work they are designed to handle.

The router can use deterministic rules, a classifier, a language model, or a combination.

How routing works

A customer-support system may route billing questions to a billing agent, technical problems to a troubleshooting agent, and ambiguous requests to a general agent for clarification.

Routing decisions may consider:

• user intent and domain;
• required tools or permissions;
• language or modality;
• risk and approval requirements;
• agent availability, latency, and cost;
• confidence in the classification.

A low-confidence route should have a fallback rather than forcing a potentially wrong specialist.

Agent router versus supervisor agent

A supervisor agent manages ongoing work, assigns tasks, reviews results, and may request corrections. A router primarily chooses the destination.

The router may act once at the beginning or at selected branch points. It does not necessarily own the final outcome.

Agent router versus orchestrator

An orchestrator coordinates dependencies, state, retries, and execution across a broader process. Routing is one orchestration function.

An orchestrator may contain a router, but it also manages what happens before and after the route. A standalone router can be much simpler.

Common failures

Overlapping agent descriptions can make routing unstable. A model router may be persuaded by untrusted text or choose a specialist based on superficial wording. Hard routes can also hide multi-intent requests that require more than one capability.

Builders should use distinct routing criteria, confidence thresholds, representative evaluation sets, and safe default paths. Permission checks must occur after routing as well; selecting an agent does not authorize its actions.

Why it matters

Routing helps multi-agent systems stay modular and context-efficient. It can reduce unnecessary tool exposure and let each agent use focused instructions.

However, routing creates an early decision that can shape the entire task. Good systems record the selected route and reason, support re-routing when evidence changes, and distinguish classification from supervision. See [Single-Agent vs Multi-Agent Systems](/single-agent-vs-multi-agent-systems/) for when specialized agents are justified.