Use cases· Last updated 2026-09-21

Routing decision workflow with Jev

Not every request deserves the same handler. Jev classifies cheaply; code sends work to a lookup, a specialist LLM, a costlier model, or a human.

This unofficial page is the decision workflow slice of the intent and model routing pack. Intent: apply the Jev (TypeSafe System One) decision model to intent and model routing decision workflow. Primary search language: Routing Jev decision workflow. Confirm patterns on docs.typesafe.ai. This site does not sell, issue, or proxy TypeSafe keys. Use a credential you already have from the console or a documented gateway.

Independent angle (cover ≠ clone): Routing glossary + compare vs rules/queues; ranked-route floors. Not a clone of a rival intent-routing glossary page.

Routing use-case context

Intent and model routing is a workflow, not a chat. Assemble a narrow state, ask the primitives below, and let the front-door router branch. TypeSafe’s docs say a good question is a snap decision a knowledgeable person could make in a few seconds — not an open-ended analysis of the latest user request.

Hub: Intent routing. Compare, when the other tool is the real job: rules and queues.

Decision Workflow inputs

Keep only fields the questions name:

{
  "user": { "message": "Where is order 8831?", "locale": "en" },
  "session": { "authenticated": true, "plan": "free" },
  "catalog": { "handlers": ["order_status", "product_question", "return_exchange", "complaint", "other"] }
}

Point instructions at user.message, session.authenticated. Drop full order-line JSON when the intent might be a product question; every historical session turn.

Decision signals and actions

All of these share state and run in parallel. Code owns the graph:

def route(ans):
    intent = ans["intent"]
    if intent.confidence < FLOOR:
        return "human"
    if intent.choice == "order_status":
        return "sql_lookup"
    if intent.choice == "complaint":
        c = ans["complexity"]
        if c.score > 1 or c.confidence < FLOOR:
            return "human"
        return "complaint_llm"
    if intent.choice == "other":
        return "human"
    return f"llm:{intent.choice}"

Do not treat a Noul of 0.5 as a “medium” intent and model routing score — it means yes and no are equally likely. Conjunctions stay in your code.

Guardrails and escalation

TypeSafe’s confidence-gated examples use a lower bar for recoverable reads than for irreversible actions. Those numbers are illustrations. For intent and model routing, treat complaint_auto_llm as the high bar (opening a refund/complaint LLM path or jumping to a costly model). Tune on labels — see offline evaluation.

Low confidence, intent == other, or a policy miss → human or safe default; do not open a refund path or jump to a costly model.

Evaluation and rollout notes

Shadow: Record selected handler next to the current rules engine; serve the old route.

Canary: Auto-act order_status only; keep complaint on the old path.

Pin jev-1.13.0 (the versioned id) after you fit thresholds. jev-latest and the marketing line jev-1.13 can move. Log the response model. TypeSafe’s published list price for jev-1.13 is $0.042 per million input tokens (vendor claim — confirm on the models page); output tokens are free on that same page. Unused distractors still bill as input.

Official Python and JavaScript SDKs read TYPESAFE_API_KEY and retry documented 429/529. This site does not sell, issue, or proxy TypeSafe keys. Use a credential you already have from the console or a documented gateway.

Pack map

FAQ

Does Jev execute the front-door router action? No. It returns typed answers. Your front-door router code calls queues, models, or humans.

Why several questions in one request? TypeSafe’s fan-out pattern: extra questions are cheap versus another HTTP call. Intent + complexity (+ optional model_class) belong in one request. Do not pay a second System One call just to pick the specialist prompt.

Where is the rest of the Routing pack? Start with Routing input contracts and Routing confidence thresholds. Cluster hub: Use cases.

Is intent a reserved API field? No. You name the key. See glossary: intent.

When do rules beat Jev? When the route is already in structured data. Compare traditional routing.

What this page does not claim

• No claimed win-rate versus regex routers.
• LangChain ModelRouterMiddleware APIs are LangChain’s — believe their docs if they move.
• Not official TypeSafe.
• Official TypeSafe status, or that jev.pro issues API keys.
• That a schema-constrained answer is automatically factually correct.

Disclaimer

This is an independent unofficial site and is not affiliated with TypeSafe AI; official documentation is available at https://docs.typesafe.ai.

Primary documentation: https://docs.typesafe.ai. Hub: Use cases.