import { initClient } from 'messagebird'; const mbClient = initClient(''); mbClient.messages.read('', ( // $ExpectType Error | null err, // $ExpectType Message | null message ) => {}); mbClient.messages.create( { originator: '', recipients: [3161234567, '3161234567'], body: '' }, ( // $ExpectType Error | null err, // $ExpectType Message | null message ) => {} );