Slack Reactions API

Slack's Reactions API lets apps programmatically manage emoji reactions on messages and files, making it easy to capture lightweight feedback like approvals, acknowledgments, or votes. Through Web API methods (reactions.add, reactions.remove, reactions.get, reactions.list) and the Events API (reaction_added and reaction_removed), apps can add or delete reactions, read which reactions are on an item, and monitor reaction activity in real time.