The defaultRouter option in createNetwork defines how agents are coordinated within a Network. It can be either a Function Router or a Routing Agent.

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Function Router

A function router is provided to the defaultRouter option in createNetwork.

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Example

const network = createNetwork({
  agents: [classifier, writer],
  router: ({ lastResult, callCount, network, stack, input }) => {
    // First call: use the classifier
    if (callCount === 0) {
      return classifier;
    }

    // Get the last message from the output
    const lastMessage = lastResult?.output[lastResult?.output.length - 1];
    const content =
      lastMessage?.type === "text" ? (lastMessage?.content as string) : "";

    // Second call: if it's a question, use the writer
    if (callCount === 1 && content.includes("question")) {
      return writer;
    }

    // Otherwise, we're done!
    return undefined;
  },
});

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Parameters

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input
string
The original input provided to the network.
​
network
Network
The network instance, including its state and history.See Network.State for more details.
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stack
Agent[]
The list of future agents to be called. (internal read-only value)
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callCount
number
The number of agent calls that have been made.
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lastResult
InferenceResult
The result from the previously called agent.See InferenceResult for more details.

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Return Values

Return TypeDescription
AgentSingle agent to execute next
Agent[]Multiple agents to execute in sequence
RoutingAgentDelegate routing decision to another routing agent
undefinedStop network execution

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createRoutingAgent()

Creates a new routing agent that can be used as a defaultRouter in a network.

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Example

import { createRoutingAgent, createNetwork } from "@inngest/agent-kit";

const routingAgent = createRoutingAgent({
  name: "Custom routing agent",
  description: "Selects agents based on the current state and request",
  lifecycle: {
    onRoute: ({ result, network }) => {
      // Get the agent names from the result
      const agentNames = result.output
        .filter((m) => m.type === "text")
        .map((m) => m.content as string);

      // Validate that the agents exist
      return agentNames.filter((name) => network.agents.has(name));
    },
  },
});

// classifier and writer Agents definition...

const network = createNetwork({
  agents: [classifier, writer],
  router: routingAgent,
});

​
Parameters

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name
string
required
The name of the routing agent.
​
description
string
Optional description of the routing agent’s purpose.
​
lifecycle
object
required
​
model
AiAdapter.Any
Optional model to use for routing decisions. If not provided, uses the network’s defaultModel.

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Returns

Returns a RoutingAgent instance that can be used as a network’s defaultRouter.