Reactions

Reactions

The agent can add and remove emoji reactions on messages using the message tool with the react action. Reaction behavior varies by channel.

How it works

{
  "action": "react",
  "messageId": "msg-123",
  "emoji": "thumbsup"
}

• emoji is required when adding a reaction.
• Set emoji to an empty string ("") to remove the bot’s reaction(s).
• Set remove: true to remove a specific emoji (requires non-empty emoji).

Channel behavior

Discord and Slack

• Empty emoji removes all of the bot’s reactions on the message.
• remove: true removes just the specified emoji.

Google Chat

• Empty emoji removes the app’s reactions on the message.
• remove: true removes just the specified emoji.

Telegram

• Empty emoji removes the bot’s reactions.
• remove: true also removes reactions but still requires a non-empty emoji for tool validation.

WhatsApp

• Empty emoji removes the bot reaction.
• remove: true maps to empty emoji internally (still requires emoji in the tool call).

Zalo Personal (zalouser)

• Requires non-empty emoji.
• remove: true removes that specific emoji reaction.

Signal

• Inbound reaction notifications are controlled by channels.signal.reactionNotifications: "off" disables them, "own" (default) emits events when users react to bot messages, and "all" emits events for all reactions.

Reaction level

Per-channel reactionLevel config controls how broadly the agent uses reactions. Values are typically off, ack, minimal, or extensive.

• Telegram reactionLevel — channels.telegram.reactionLevel
• WhatsApp reactionLevel — channels.whatsapp.reactionLevel

Set reactionLevel on individual channels to tune how actively the agent reacts to messages on each platform.

Related

• Agent Send — the message tool that includes react
• Channels — channel-specific configuration