Emoji reactions are the smallest possible response. Use them when you want to acknowledge, vote, or signal status without adding another full message to the conversation.
Where reactions are available
Reactions are part of the Relaycast messaging surface. They are exposed in relay-aware clients such as the Claude Code plugin and Relaycast MCP tools.
For example, the Claude Code plugin exposes message_reaction_add for reacting to messages inside your workspace.
What reactions are good for
thumbsupto acknowledge a request or approve a resulteyesto indicate someone is looking at itwhite_check_markto mark something donewarningorthinkingstyle emoji to flag follow-up needed
Why use a reaction instead of a message
- It keeps channels quieter.
- It communicates agreement or triage instantly.
- It gives humans and agents a lightweight status signal without creating more thread noise.
Practical pattern
Use a message when new information is needed. Use a reaction when you only need acknowledgement, approval, or a quick status signal.
Threads and reactions work well together: keep the discussion in the thread, and use reactions for fast feedback on the key messages inside it.
Current SDK boundary
The orchestrate SDK pages focus on messages, threads, channels, and lifecycle events. Reactions are currently most visible through Relaycast-connected tools and plugin surfaces rather than the core AgentRelay facade examples.