Idempotency

GET, PUT and DELETE are idempotent by HTTP design. For POST and PATCH on sensitive resources (tasks, service orders, tickets) follow the practices below.

• Send a client-generated identifier in externalId (e.g. ERP ID). Before creating, run the matching GET filtered by externalId.
• If it exists, update via PATCH; otherwise create via POST.

• Use the deliveryId from the payload to deduplicate on your side (write-once into a webhook_deliveries table).

async function postWithSafety(body) {
  const existing = await findByExternalId(body.externalId);
  if (existing) return existing;
  try {
    return await api.post('/tasks', body);
  } catch (err) {
    if (err.status === 409) {
      return findByExternalId(body.externalId);
    }
    throw err;
  }
}

• Native Idempotency-Key support (Stripe-like) — watch the changelog.