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typescript · 2026-09-23

REST Jev Review Gate

Call the Jev System One endpoint without an SDK, using bounded retries and explicit response checks.

Use cases

  • Edge services
  • Small server handlers
  • SDK evaluation

Dependencies and versions

  • Node.js 20+

Expected behavior

The request returns a validated choice or human_review after at most three attempts.

Failure behavior

Permanent HTTP failures, timeouts after the retry budget, and malformed payloads stop the workflow.

Code template
const API_URL = 'https://api.typesafe.ai/v1/systemone';
const MAX_RETRIES = 2;
const apiKey = process.env.TYPESAFE_API_KEY;

if (!apiKey) throw new Error('TYPESAFE_API_KEY is required');

const requestBody = {
  model: 'jev-latest',
  state: { ticket: 'I was charged twice. Please fix this ASAP.' },
  questions: {
    route: {
      type: 'choice',
      instructions: 'Choose the support queue.',
      criteria: { billing: null, technical: null, other: null },
    },
  },
};

const retryable = (status) =>
  status === 408 || status === 429 || status >= 500;

let response;
for (let attempt = 0; attempt <= MAX_RETRIES; attempt += 1) {
  response = await fetch(API_URL, {
    method: 'POST',
    headers: {
      Authorization: `Bearer ${apiKey}`,
      'Content-Type': 'application/json',
    },
    body: JSON.stringify(requestBody),
    signal: AbortSignal.timeout(10_000),
  });

  if (response.ok || !retryable(response.status) || attempt === MAX_RETRIES) {
    break;
  }
  await new Promise((resolve) => setTimeout(resolve, 500 * 2 ** attempt));
}

if (!response?.ok) {
  throw new Error(`TypeSafe request failed with HTTP ${response?.status}`);
}

const payload = await response.json();
const decision = payload?.answers?.route;
if (
  typeof decision?.choice !== 'string' ||
  !Number.isFinite(decision?.confidence) ||
  decision.confidence < 0 ||
  decision.confidence > 1
) {
  throw new Error('Unexpected decision response');
}

const action = decision.confidence < 0.8 ? 'human_review' : decision.choice;
console.log({ action, confidence: decision.confidence, model: payload.model });

Sources

This example calls a third-party service. Before copying it, verify the current API, dependency version, cost, privacy requirements, and service terms.