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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 blockMust 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 buttonAllowed 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.
PropertyTypeDescription
titlestringDialog title
textstringConfirmation message
confirm_textstringText for the confirm button
deny_textstringText for the cancel button
​
disabled
boolean
default:"false"
required
When true, the button is rendered in a disabled state and cannot be clicked.

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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"
}

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Server Response

The server can respond with one of these action types:
Response TypeDescription
replaceReplace the entire block with new BlockKit content
updateUpdate specific properties of the block
appendAppend new blocks after the current block
errorsDisplay 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