咧 is a modal particle (语气词) placed at the end of a sentence to express exclamation, enthusiasm, or a casual confirmatory tone. It is similar to 啊 or 啦 but with a slightly more rustic or cheerful feel, often appearing in informal or dialectal speech. You'll encounter it in phrases like 好咧 (okay! / alright!) and 对咧 (that's right!).