React to statuses

createSdk({ onStatus }) maps a status to a handler. It is the place for the reactions that belong to the whole application and not to one call: log out on a 401, redirect on a 403, report a 5xx.

import { createSdk } from 'nexdk'

const sdk = createSdk({
  drivers: { lomkit },
  onStatus: {
    401: async () => {
      await session.logout()
      await router.push('/login')
    },
    403: () => router.push('/forbidden'),
    '5xx': ({ error, resource }) => report(`${resource}: ${error.message}`),
  },
})

Keys

• An exact status (401, 403, 409…).
• A family: '4xx' or '5xx'.

The exact status wins over the family: with { 403: a, '4xx': b }, a 403 calls a and a 404 calls b. A status without a handler does nothing. A network failure (status 0) and an error without a numeric status never match.

The handler

It receives one object:

Field	Value
error	The error of the call (an SdkError with status, errors and data).
driver	The driver name, for example lomkit.
resource	The resource key of the call, for example users.
method	The driver method, for example get.

Rules

• It runs once per failed call, after notify and the per-call onEvent have received the error event.
• It may be asynchronous. The call waits for it before resolving { data: undefined, error } (or rejecting with throw: true), so a logout is finished when you read error.
• It never hides the failure: error is still the original error.
• If it throws (or rejects), the exception is dropped. The notification and the original error are not affected.
• There is no retry and no token refresh. The handler observes the failure, it does not replay the call.

In an OSDD app

Declare the handlers once, in the technical layer that builds the SDK, so functional layers only see { data, error }.

import { createSdk } from 'nexdk'
import { LomkitDriver } from '@nexdk/driver-lomkit'

export function createApiSdk(session: Session, router: Router) {
  return createSdk({
    drivers: { lomkit: new LomkitDriver({ baseUrl: '/api', headers: () => session.headers() }) },
    onStatus: {
      401: async () => {
        await session.logout()
        await router.push('/login')
      },
      403: () => router.push('/forbidden'),
    },
  })
}

Per-call messages stay with events: onStatus is for application-wide reactions.