Button

An interactive button that triggers an action when clicked

Basic Example

{
  "type": "button",
  "text": "Submit",
  "action_id": "submit_btn",
  "style": "primary"
}

Complete Example

Example Code

[
  {
    "type": "actions",
    "action_url": "https://api.example.com/actions",
    "elements": [
      {
        "type": "button",
        "text": "Approve",
        "action_id": "approve_btn",
        "value": "approved",
        "style": "primary"
      },
      {
        "type": "button",
        "text": "Reject",
        "action_id": "reject_btn",
        "value": "rejected",
        "style": "danger",
        "confirm": {
          "title": "Are you sure?",
          "text": "This action cannot be undone.",
          "confirm_text": "Yes, reject",
          "deny_text": "Cancel"
        }
      },
      {
        "type": "button",
        "text": "View Details",
        "action_id": "view_btn",
        "url": "https://example.com/details"
      }
    ]
  }
]

Properties

type · string · required

Identifies this as a button block

Must be button

text · string · required

The visible label text displayed on the button

action_id · string · required

A unique identifier for the button action. Included in the action payload when the button is clicked.

value · string · required

An optional value sent with the action payload when clicked. Useful for passing data to the action handler.

style · string · default: "default" · required

The visual style of the button

Allowed values: primary, danger, default

url · string · required

A URL to open when the button is clicked. When set, the button acts as a link instead of triggering an action POST.

action_url · string · required

The endpoint URL to POST the action payload to when clicked. If not set, the parent actions block’s action_url is used.

confirm · object · required

An optional confirmation dialog shown before the action is executed.

Property	Type	Description
title	string	Dialog title
text	string	Confirmation message
confirm_text	string	Text for the confirm button
deny_text	string	Text for the cancel button

disabled · boolean · default: "false" · required

When true, the button is rendered in a disabled state and cannot be clicked.

Action Payload

When a button is clicked, the following payload is POSTed to the action_url:

{
  "type": "button_click",
  "action_id": "approve_btn",
  "value": "approved",
  "block_id": "actions_123"
}

Server Response

The server can respond with one of these action types:

Response Type	Description
replace	Replace the entire block with new BlockKit content
update	Update specific properties of the block
append	Append new blocks after the current block
errors	Display validation errors

{
  "action": "replace",
  "blocks": [
    {
      "type": "alert",
      "severity": "success",
      "text": "Request approved successfully!"
    }
  ]
}

Usage Notes

• Buttons are typically placed inside an Actions block
• Buttons can also be placed inside Section and Column Layout blocks
• When url is set, the button opens the URL instead of sending an action POST
• The confirm dialog provides a safety net for destructive or irreversible actions