Block Kit is a Slack framework to create complex interactions with the chatbot (panels, buttons, UI elements), the “Block” can be visually composed using the Block Kit Builder.

When the Block is ready, just copy and paste the JSON in the Slack Blocks node, for example:

{  
	"text": "Fallback text",
  "blocks": [    
		{      
			"type": "section",      
			"text": { 
				"type": "mrkdwn",        
				"text": "Hello *{{firstName}}*"      
			}    
		},    
		{      
			"type": "actions",      
			"block_id": "my_block_id",      
			"elements": [        
				{          
					"type": "button",          
					"text": {            
						"type": "plain_text",            
						"text": "Say Hello",            
						"emoji": true          
					},          
					"value": "the_value"        
				}      
			]    
		}  
	]
}

In any part of the JSON is also possible to use the chat context variables.

For interactive Blocks the result of the user interactions is sent to the chatbot as a response type message (like Slack Dialog node ), the payload is an hash object that contains the block_id of the UI element (a button, a dropdown, etc) and related value. If the block_id is not specified in the JSON, it will be auto-generated one.

For example clicking the button in the example above will send the following message to the chatbot

{  
	type: 'response',  
	content: {    
		my_block_id: 'the_value'  
	}
}

A response type message can be chained directly to a [[Context node|Context-node]] to store the results directly in the current user chat context.

Example Slack Blocks

The JSON can be passed through the payload by the upstream node:

msg.payload = {  
	blocks: '[{ ... }]'
};

Available parameters for the msg.payload