The machine gate,
made passable.

import { createMaskinportenClient } from 'maskinporten';

// Describe your credentials once.
const client = createMaskinportenClient({
  env: 'test',
  clientId: process.env.MASKINPORTEN_CLIENT_ID!,
  scope: 'skatteetaten:formueinntekt/skattemelding',
  key: {
    pem: process.env.MASKINPORTEN_PRIVATE_KEY!,
    kid: process.env.MASKINPORTEN_KID!,
  },
});

// One call. The token is cached and auto-renewed for you.
const token = await client.getToken();

// getToken() caches and renews under the hood,
// so it is safe to call on every request.
const token = await client.getToken();

// Call the API your scope was granted for.
const response = await fetch('https://api.example.no/v1/resource', {
  headers: { Authorization: `Bearer ${token}` },
});

const data = await response.json();

// Add the organisation you act on behalf of...
const client = createMaskinportenClient({
  env: 'test',
  clientId: process.env.MASKINPORTEN_CLIENT_ID!,
  scope: 'altinn:instances.read',
  key: {
    pem: process.env.MASKINPORTEN_PRIVATE_KEY!,
    kid: process.env.MASKINPORTEN_KID!,
  },
  systemUserOrg: '991825827',
});

// ...and the two-step Maskinporten to Altinn exchange,
// with its own caching, is a single call.
const altinnToken = await client.exchangeToAltinnToken();

// Terminal:  npx maskinporten-mock   (listens on :6969)
import { createMaskinportenClient } from 'maskinporten';

const client = createMaskinportenClient({
  env: 'test',
  clientId: 'local-dev',
  scope: 'demo:scope',
  key: { pem: process.env.DEV_PRIVATE_KEY!, kid: 'dev' },
  // Point the client at the local mock. That is the only change.
  tokenEndpoint: 'http://localhost:6969/token',
});

// Real JWT-bearer flow, fake gate. No credentials, offline, CI-ready.
const token = await client.getToken();

import { createMaskinportenClient, MaskinportenError } from 'maskinporten';

try {
  const token = await client.getToken();
} catch (error) {
  if (error instanceof MaskinportenError) {
    // Opaque codes like AUTH-00004 arrive decoded and readable.
    console.error(error.code, error.description);
  }
  throw error;
}