Routing

This interface is experimental — no production implementation exists yet. The API surface may change.

Overview

The Routing workflow classifies an incoming prompt and delegates it to a single specialized workflow based on the classification result. It is the simplest multi-agent pattern — it routes but does not aggregate results across multiple branches. The design follows Anthropic's routing building block from "Building Effective Agents."

Pattern

TypeScript API

Import from osprotocol/workflows/routing. The base Workflow interface is available from osprotocol/workflows.

RouteConfig

Describes when a route should be selected and provides optional examples for few-shot classification.

interface RouteConfig {
  description: string
  whenToUse: string[]
  examples?: string[]
}

RoutingWorkflow

Extends the base Workflow interface with a classify method that returns the key of the matched route.

interface RoutingWorkflow<Output> extends Workflow<Output> {
  classify(prompt: string): Promise<string>
}

RoutingWorkflowConfig

Top-level configuration object. workflows is a record keyed by route name, each value being a RoutingWorkflowEntry.

interface RoutingWorkflowConfig<Output> {
  model?: string
  workflows: Record<string, RoutingWorkflowEntry<Output>>
}

RoutingWorkflowEntry

Pairs a concrete Workflow with its RouteConfig. Set markAsDefault to true on one entry to use it as the fallback when no route matches.

interface RoutingWorkflowEntry<Output> {
  workflow: Workflow<Output>
  route: RouteConfig
  markAsDefault?: boolean
}

Usage Examples

Configure a routing workflow with multiple routes

const config: RoutingWorkflowConfig<string> = {
  model: "claude-opus-4-6",
  workflows: {
    billing: {
      workflow: billingWorkflow,
      route: {
        description: "Handles billing, invoices, and payment questions.",
        whenToUse: [
          "User asks about an invoice",
          "User wants to update payment method",
          "User reports a charge they do not recognize",
        ],
        examples: [
          "Why was I charged twice this month?",
          "How do I cancel my subscription?",
        ],
      },
    },
    technical: {
      workflow: technicalWorkflow,
      route: {
        description: "Handles technical support and troubleshooting.",
        whenToUse: [
          "User reports a bug or error",
          "User needs help integrating the API",
          "User asks how a feature works",
        ],
      },
    },
    general: {
      workflow: generalWorkflow,
      route: {
        description: "Handles all other questions.",
        whenToUse: ["Input does not match any other route"],
      },
      markAsDefault: true,
    },
  },
}

Classify a prompt to determine the route

const routeKey = await router.classify("I was charged twice last week.")
// routeKey === "billing"

Run the full routing workflow

const run = await router.run("I was charged twice last week.")
const result = await run.output()

The run method internally calls classify, selects the matching RoutingWorkflowEntry, and delegates execution to its workflow. If no route matches, the entry with markAsDefault: true is used.

Integration

Orchestrator-Workers — plan, delegate to multiple workers, and synthesize results
Parallelization — split a task across concurrent workflows
Evaluator-Optimizer — generate, evaluate, and refine output in a loop
Runs — timeout, retry, cancel, and approval controls for any workflow

On this page