Jev migration: move from TypeSafe Jev to Laya Studio

The open-source Laya package implements TypeSafe Jev's /v1/systemone wire protocol, and Laya Studio exposes it unchanged. In plain terms: your existing Jev code keeps working after you change two values, the address and the key. Laya Studio is an independent service, not affiliated with TypeSafe.

Before and after

Toggle between your Jev client and the same client on Laya Studio. Only the highlighted lines change.

the same client on Laya Studio2 lines changed

const BASE = "https://api.laya.studio";const KEY = process.env.LAYA_API_KEY; // lsk_live_… const res = await fetch(`${BASE}/v1/systemone`, {  method: "POST",  headers: { Authorization: `Bearer ${KEY}`, "Content-Type": "application/json" },  body: JSON.stringify({ state, questions, model: "jev-latest" }),});const { answers } = await res.json();route(answers.intent.choice, answers.intent.confidence);

The request body, the question types and the answer fields stay the same. A Jev model id such as jev-latest is accepted and ignored.

Migration checklist

Tick items off as you go. Your progress is remembered in this browser.

0 of 8 done

1. Create a Laya Studio API keyDashboard → API keys → Create key. Store it as LAYA_API_KEY; it is shown once.
2. Change the base URLhttps://api.typesafe.ai → https://api.laya.studio. The path stays /v1/systemone.
3. Swap the key in the Authorization headerAuthorization: Bearer lsk_live_…
4. Check long statesLaya reads the first 512 (English) or 1,024 (multilingual) tokens per question. Put the decisive text first, or trim.
5. Split large label setsJev is much stronger on many-label questions (Banking77: 0.870 vs 0.425). Use a coarse and a fine question.
6. Shadow production traffic for a weekSend a sample to both and compare answers and confidence.
7. Re-derive your confidence thresholdsConfidence is computed differently. Measure accuracy against confidence on your own labelled data.
8. Flip the defaultPoint production at Laya Studio and keep the Jev path for rollback until you are sure.

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1. Point your client at Laya Studio

diffbash

- base URL: https://api.typesafe.ai
+ base URL: https://api.laya.studio
- Authorization: Bearer <your Jev key>
+ Authorization: Bearer lsk_live_…   # dashboard → API keys

The request body is the same: state, questions with choice / score / noul types, and model. A Jev model id such as jev-latest is accepted and ignored — Laya routes to its own checkpoint automatically.

2. Check what differs

Area	Meaning
`Context`	Jev accepts up to 32k tokens of state; Laya reads the first 512 (English) or 1,024 (multilingual) tokens per question. Trim or summarise long states.
`Confidence`	Both return a confidence, computed differently. Laya: 1 − normalised entropy (choice/score), max(p, 1−p) for noul. Re-derive thresholds on your own labelled data.
`Large label sets`	Jev is much stronger on many-label questions (Banking77: 0.870 vs 0.425). Split large taxonomies before migrating them.
`Extra fields`	Laya adds routing and action.act_probability; Jev clients ignore unknown fields.
`Pricing`	Both bill input tokens, in the same unit: Jev lists $0.042 per 1M input tokens, Laya Studio $0.0294 per 1M input tokens (30% less). 1 credit = 1 input token; 5 free runs per new workspace.

3. Shadow before you switch

Send a sample of production traffic to both for a week and compare answers and confidence before flipping the default.

TypeScriptts

const body = { state, questions, model: "jev-latest" };
const [jev, laya] = await Promise.all([
  fetch("https://api.typesafe.ai/v1/systemone", { method: "POST", headers: { Authorization: `Bearer ${JEV_KEY}`, "Content-Type": "application/json" }, body: JSON.stringify(body) }).then(r => r.json()),
  fetch("https://api.laya.studio/v1/systemone", { method: "POST", headers: { Authorization: `Bearer ${LAYA_KEY}`, "Content-Type": "application/json" }, body: JSON.stringify(body) }).then(r => r.json()),
]);
for (const id of Object.keys(questions)) log(id, jev.answers[id], laya.answers[id]);

The full, sourced comparison is at Laya vs Jev.