get-quota-token.ts

export const getQuotaToken = functions.https.onCall(async ({ id }, context) => {
  if (!context.auth) {
    throw new functions.https
      .HttpsError('failed-precondition', 'The function must be called while authenticated.');
  }

  const { uid } = context.auth;
  const usage = await getUsage(uid);
  const quota = context.auth.token.quota || DEFAULT_QUOTA;
  const remaining = quota - usage;

  const path = `${uid}/${id}`;
  const token = await admin.auth().createCustomToken(uid, { remaining, path });
  return { token, quota, usage, remaining };
});