Reference: Block actions payloads

A block_actions payload is received when a user interacts with a Block Kit interactive component.

Read our guide to handling payloads from user interactions to learn how your app should process and respond to these payloads.


Timing of payload dispatch

Different interactive components will cause an interaction payload to be sent at different moments:

Component Payload sent
button When the button is clicked.
checkboxes When a checkbox is ticked or unticked.
datepicker When a date is chosen and the date picker closes.
multi_*_select Each time an item is chosen from the multi-select menu.
overflow When an item from the overflow menu is clicked.
plain_text_input Determined by the dispatch_action_config field in the element.
radio When the selected radio in a group of radio buttons is changed.
*_select When an item is chosen from the select menu.
rich_text_input Determined by the dispatch_action_config field in the element.

Deselecting the currently selected option of a Block Kit static option will return a null value. For more information about select menu elements, refer to select menu of static options.

To send this block_actions payload for interactive components used within input blocks, you can set dispatch_action to true in those input blocks. They are included in view_submission payloads as well.

Properties

This is a list of some properties that can be encountered in this type of interaction payload:

Properties received in a block_actions event may differ based on the source of the interactive elements. A check in the column means that property is included in a block_actions event sent to a function, a non-function, or both. Functions refer to workflow apps.

Property Functions Non-Functions Description Required?
type βœ“ βœ“ Helps identify which type of interactive component sent the payload; An interactive element in a block will have a type of block_actions, whereas an interactive element in a message attachment will have a type of interactive_message. Yes
trigger_id βœ“ βœ“ A short-lived ID that can be used to open modals. Yes
user βœ“ βœ“ The user who interacted to trigger this request. Yes
team βœ“ βœ“ The workspace the app is installed on. Null if the app is org-installed. Yes
container βœ“ βœ“ The container where this block action took place. Yes
api_app_id βœ“ βœ“ A string representing the app ID. Yes
actions.block_id βœ“ βœ“ Identifies the block within a surface that contained the interactive component that was used. See the reference guide for the block you're using for more info on the block_id field. Yes
actions.action_id βœ“ βœ“ Identifies the interactive component itself. Some blocks can contain multiple interactive components, so the block_id alone may not be specific enough to identify the source component. See the reference guide for the interactive element you're using for more info on the action_id field. Yes
actions.value βœ“ βœ“ Set by your app when you composed the blocks, this is the value that was specified in the interactive component when an interaction happened. For example, a select menu will have multiple possible values depending on what the user picks from the menu, and value will identify the chosen option. See the reference guide for the interactive element you're using for more info on the value field. Yes
token βœ“ Represents a deprecated verification token feature. You should validate the request payload, however, and the best way to do so is to use the signing secret provided to your app. Yes
hash βœ“ βœ“ A unique value that is optionally accepted in views.update and views.publish API calls. When provided to those APIs, the hash is validated such that only the most recent view can be updated. This should be used to ensure the correct view is being updated when updates are happening asynchronously. Yes
function_data βœ“ Metadata about the function execution that generated the block where this block action took place. Yes
interactivity βœ“ An interactivity object generated as a result of the block action. Yes
bot_access_token βœ“ A workflow (just-in-time) token generated for this block action. Yes
enterprise βœ“ βœ“ The enterprise the installed app is part of, if the app is either workspace-installed on an org, or org-installed. No
channel βœ“ βœ“ The channel where this block action took place. No
message βœ“ βœ“ The message where this block action took place, if the block was contained in a message. No
view βœ“ βœ“ The view where this block action took place, if the block was contained in a view. No
actions βœ“ βœ“ Contains data from the specific interactive component that was used. App surfaces can contain blocks with multiple interactive components, and each of those components can have multiple values selected by users. No
state βœ“ βœ“ A property including all stateful elements, not just input blocks. No
response_url βœ“ (Deprecated for workflow apps) A short-lived webhook that can be used to send messages in response to interactions. No

If a user doesn't interact with a form field β€” for example, they don't select a value from a drop-down field on a modal β€” the value of that field is returned as None.

Examples

A payload from an interactive component used in a message:

{
  "type": "block_actions",
  "team": {
    "id": "T9TK3CUKW",
    "domain": "example"
  },
  "user": {
    "id": "UA8RXUSPL",
    "username": "jtorrance",
    "team_id": "T9TK3CUKW"
  },
  "api_app_id": "AABA1ABCD",
  "token": "9s8d9as89d8as9d8as989",
  "container": {
    "type": "message_attachment",
    "message_ts": "1548261231.000200",
    "attachment_id": 1,
    "channel_id": "CBR2V3XEX",
    "is_ephemeral": false,
    "is_app_unfurl": false
  },
  "trigger_id": "12321423423.333649436676.d8c1bb837935619ccad0f624c448ffb3",
  "channel": {
    "id": "CBR2V3XEX",
    "name": "review-updates"
  },
  "message": {
    "bot_id": "BAH5CA16Z",
    "type": "message",
    "text": "This content can't be displayed.",
    "user": "UAJ2RU415",
    "ts": "1548261231.000200",
    ...
  },
  "response_url": "https://hooks.slack.com/actions/AABA1ABCD/1232321423432/D09sSasdasdAS9091209",
  "actions": [
    {
      "action_id": "WaXA",
      "block_id": "=qXel",
      "text": {
        "type": "plain_text",
        "text": "View",
        "emoji": true
      },
      "value": "click_me_123",
      "type": "button",
      "action_ts": "1548426417.840180"
    }
  ]
}

A payload from an interactive component used in a Home tab:

{
    "type":"block_actions",
    "team":{
        "id": "T9TK3CUKW",
        "domain": "example"
    },
    "user":{
        "id": "UA8RXUSPL",
        "username": "jtorrance",
        "name": "jtorrance",
        "team_id": "T9TK3CUKW"
    },
    "api_app_id":"AABA1ABCD",
    "token":"9s8d9as89d8as9d8as989",
    "container":{
        "type":"view",
        "view_id":"V0PKB1ZFV"
    },
    "trigger_id":"24571818370.22717085937.b9c7ca14b87be6b44ff5864edba8306f",
    "view":{
      "id":"V0PKB1ZFV",
      "team_id":"T9TK3CUKW",
      "type":"home",
      "blocks":[
          {
            "type":"section",
            "block_id":"8ZG",
            "text":{
                "type":"mrkdwn",
                "text":"A stack of blocks for the sample Block Kit Home tab.",
                "verbatim":false
            }
          },
          {
            "type":"actions",
            "block_id":"7fhg",
            "elements":[
                {
                  "type":"button",
                  "action_id":"XRX",
                  "text":{
                      "type":"plain_text",
                      "text":"Action A",
                      "emoji":true
                  }
                },
                {
                  "type":"button",
                  "action_id":"GFBew",
                  "text":{
                      "type":"plain_text",
                      "text":"Action B",
                      "emoji":true
                  }
                }
            ]
          },
          {
            "type":"section",
            "block_id":"6evU",
            "text":{
                "type":"mrkdwn",
                "text":"And now it's slightly more complex.",
                "verbatim":false
            }
          }
      ],
      "private_metadata":"",
      "callback_id":"",
      "state":{
          "values":{}
      },
      "hash":"1571318366.2468e46f",
      "clear_on_close":false,
      "notify_on_close":false,
      "close":null,
      "submit":null,
      "previous_view_id":null,
      "root_view_id":"V0PKB1ZFV",
      "app_id":"AABA1ABCD",
      "external_id":"",
      "app_installed_team_id":"T9TK3CUKW",
      "bot_id":"B0B00B00"
    },
    "actions":[
      {
          "type":"button",
          "block_id":"7fhg",
          "action_id":"XRX",
          "text":{
            "type":"plain_text",
            "text":"Action A",
            "emoji":true
          },
          "action_ts":"1571318425.267782"
      }
    ]
}