kelvinmade✳Independent maker ↗
JEV USE CASE

Agent Tool Selection.

Choose the next tool or specialist agent from a bounded set, then let ordinary code validate and execute it.

THE DECISION CONTRACT
STATE

The user asks to compare today’s forecast with an event already on their calendar.

QUESTION

Which capability should handle this turn?

CHOICES

weather calendar general_reasoning ask_user

TYPESCRIPT EXAMPLE

Ask for one bounded answer

This Vercel AI SDK-shaped example is illustrative. Check the current provider documentation before shipping.

import { experimental_evaluate as evaluate } from 'ai';

const result = await evaluate({
  model: 'typesafe-ai/jev',
  state: "The user asks to compare today’s forecast with an event already on their calendar.",
  questions: {
    decision: {
      type: 'choice',
      instructions: "Which capability should handle this turn?",
      options: ["weather","calendar","general_reasoning","ask_user"]
    }
  }
});

// Validate permissions and thresholds before acting.
console.log(result.answers.decision);
SAFE IMPLEMENTATION

Keep the boundary clear

Guardrail

Jev should suggest a route—not receive credentials or execute the tool. Keep authorization and side effects in code.

  • Log the input, answer distribution, chosen threshold and resulting route.
  • Test on labelled examples from your own production distribution.
  • Send low-confidence, high-impact or out-of-distribution cases to a safer fallback.
  • Re-evaluate thresholds when the model or workflow changes.
PRIMARY SOURCES

Read before implementing

TypeSafe AI: Introducing System One Models and Jev ↗

Vercel: Jev available on AI Gateway ↗