// amplify/data/custom-authorizer.ts

// This is sample code. Update this to suite your needs
import type { AppSyncAuthorizerHandler } from 'aws-lambda'; // types imported from @types/aws-lambda

type ResolverContext = {
  userid: string;
  info: string;
  more_info: string;
};

export const handler: AppSyncAuthorizerHandler<ResolverContext> = async (
  event
) => {
  console.log(`EVENT: ${JSON.stringify(event)}`);
  const {
    authorizationToken,
    requestContext: { apiId, accountId }
  } = event;
  const response = {
    isAuthorized: authorizationToken === 'custom-authorized',
    resolverContext: {
      // eslint-disable-next-line spellcheck/spell-checker
      userid: 'user-id',
      info: 'contextual information A',
      more_info: 'contextual information B'
    },
    deniedFields: [
      "name", "address",
    ],
    ttlOverride: 300
  };
  console.log(`RESPONSE: ${JSON.stringify(response, null, 2)}`);
  return response;
};

Here is an example for simplicity. The lambda authorizer expects optional an deniedFields, where i can define all fields that i want to turn to null, however my data is big over 20 fields, and i actually just want to show for example 3 fields, that means i need to deny the rest, is it possible to somehow “allow” certain fields instead of denying?