add_reaction
Add an emoji reaction to a Slack message by specifying the channel, message timestamp, and emoji name.
Instructions
Add a reaction emoji to a message.
Args: channel: Channel ID where the message exists timestamp: Timestamp of the message emoji_name: Name of the emoji (without colons)
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| channel | Yes | ||
| timestamp | Yes | ||
| emoji_name | Yes |
Output Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Implementation Reference
- slack_mcp/server.py:410-425 (handler)MCP tool handler function for 'add_reaction' that wraps the SlackClient method and handles JSON serialization/error response.
@mcp.tool() async def add_reaction(channel: str, timestamp: str, emoji_name: str) -> str: """ Add a reaction emoji to a message. Args: channel: Channel ID where the message exists timestamp: Timestamp of the message emoji_name: Name of the emoji (without colons) """ try: client = SlackClient() result = await client.add_reaction(channel, timestamp, emoji_name) return json.dumps(result, indent=2) except Exception as e: return json.dumps({"error": str(e)}, indent=2) - slack_mcp/server.py:177-180 (helper)SlackClient helper method that makes the actual Slack API POST request to the 'reactions.add' endpoint.
async def add_reaction(self, channel: str, timestamp: str, name: str) -> Dict[str, Any]: """Add a reaction to a message.""" data = {"channel": channel, "timestamp": timestamp, "name": name} return await self._make_request("POST", "reactions.add", json_data=data)