How do you build a reliable router?

Three rules. First, define the routing categories crisply with examples—routers fail most often when categories overlap. Second, ship a fallback (an "unclear—escalate to human" route) so the router never has to force a bad classification. Third, log every routing decision and review weekly during rollout; the misroutes are where the categories need tightening.

Is a router itself an agent?

Yes, in the technical sense—it uses an LLM to make a decision. But it's a single-turn, single-decision agent with no tools, so it's the simplest possible kind. Most teams build it as a stateless classifier rather than a full looping agent. The exception is when routing requires lookups ("check this customer's tier first")—then it becomes a small two-step agent.

Agent Router

Written by Max Zeshut

Founder at Agentmelt · Last updated Jul 8, 2026

A classification layer in front of a multi-agent system that decides which specialized agent should handle each incoming request. Routers replace brittle keyword matching with LLM-based classification, allowing more nuanced routing ("this looks like a billing question with a churn signal—send to retention, not generic support"). Router design is a load-bearing component of any [[multi-agent-systems]] deployment: weak routing wastes the specialization advantage.

Example

A B2B SaaS company runs four specialized agents: a billing agent (refunds, plan changes), a technical agent (API errors, integration help), a sales agent (upgrade questions), and a retention agent (cancellation requests). The router reads each incoming ticket and routes it to the right agent based on intent + customer tier + recent activity. Routing accuracy of 92% means each specialized agent stays focused on its domain rather than handling the long tail badly.

Frequently asked questions

How do you build a reliable router?: Three rules. First, define the routing categories crisply with examples—routers fail most often when categories overlap. Second, ship a fallback (an "unclear—escalate to human" route) so the router never has to force a bad classification. Third, log every routing decision and review weekly during rollout; the misroutes are where the categories need tightening.
Is a router itself an agent?: Yes, in the technical sense—it uses an LLM to make a decision. But it's a single-turn, single-decision agent with no tools, so it's the simplest possible kind. Most teams build it as a stateless classifier rather than a full looping agent. The exception is when routing requires lookups ("check this customer's tier first")—then it becomes a small two-step agent.

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