Overview

The for expression is a foreach loop that iterates over an iterable (array/list from the data bank), binding each item to an each & index variable. It executes steps sequentially per iteration, then aggregate outputs into the output_key as a list of dicts. It is Ideal for bulk actions like user notifications.

❗️

Output Aggregation Deep Dive

The for expression outputs a clean list of objects, where one object contains the results of an iteration. An example loop with two actions,incident_manager_profile and updated_manager_profile, expect:

JSON

"for_expression_output_result": [
  {
    "incident_manager_profile": { "id": "12345", "status": "INACTIVE" },
    "updated_manager_profile": { "id": "67890", "status": "ON_CALL" }
  },
  {
    "incident_manager_profile": { "id": "1a2b3c", "status": "INACTIVE" },
    "updated_manager_profile": { "id": "4d5e6f", "status": "ON_CALL" }
  }
]

You can access the variables the same way you access any others in the data bank; e.g., data.for_expression_output_result[0].incident_manager_profile.status will yield INACTIVE

Low-Code Editor

Add a For Loop Step, bind iterable, define loop variables, and add expressions inside.

⚠️

You can only bind an iterable in in, you cannot create a list on the fly using DSL such as ["a", "b"], only data bank variables work.

You can create a precursor script action to output a list and pass it to in .

1. Bind the Iterable (in): Only data bank variables work, inline lists like ["a","b"] will fail.
2. Define each & index: Set each for item (e.g., user) and index (e.g., user_index), these are only scoped to the for loop.
3. Add expression & Set output_key: Add expressions to each step. Make sure to add readable output keys.

Syntax Reference

Schema

for:
  each: ITEM_VAR_NAME*      # str: Current item (e.g., 'user')-scoped to steps
  index: INDEX_VAR_NAME*    # str: Optional position (e.g., 'user_index')—use for ordering
  in: DATA_BANK_ITERABLE*   # str: Ref to array var (e.g., 'data.users')—no inline literals!
  output_key: RESULTS_VAR*  # str: Aggregates as list[dict] of step outputs
  steps:                    # list: Expressions per iteration (optional, but useful)
    - EXPRESSION_1          # e.g., action with {{each.record_id}}
    - EXPRESSION_2

Fields

Practical Examples

Example 1: Actions in Batch

Run actions for each user in a list

Compound Action

steps:
  - action:
      action_name: mw.batch_get_users_by_email
      output_key: user_results
      input_args:
        user_emails:
          - '"[email protected]"'
          - '"[email protected]"'
          - '"[email protected]"'
  - for:
      each: user
      index: user_index
      in: data.user_results.user_records  # From upstream fetch
      output_key: requested_for_notifications
      steps:
        - action:
            action_name: mw.send_plaintext_chat_notification
            output_key: notification_output
            input_args:
              user_record_id: user.lookup_id
              message: '''Hi, this is a batch message!'''

Expected Output

requested_for_notifications: [
  { "notification_output": { "status": "sent", "user": "user1" } },
  { "notification_output": { "status": "sent", "user": "user2" } },
  { "notification_output": { "status": "sent", "user": "user3" } }
]

The compound actions fetches the records of the users and consequentially uses a for loop to send a message to each user.

Example 2: Outage Ticket Processing

Batch-update manager for open tickets

Sample input argument

outage_tickets: [ {"system_id": "OUT-123"}, {"system_id": "OUT-456"} ]

Compound Action

for:
  each: ticket
  index: index
  in: data.outage_tickets
  output_key: outage_ticket_process_results
  steps:
    - action:
        action_name: get_incident_manager_for_outage
        input_args:
					outage_id: ticket.system_id
        output_key: incident_manager_profile
    - action:
        action_name: update_incident_manager_profile
        input_args:
          manager_id: data.incident_manager_profile.id
          status: '''ON_CALL'''
        output_key: updated_manager_profile

Expected Output

outage_ticket_process_results: [
  {
    "incident_manager_profile": { "id": "7bd99d76-...", "status": "INACTIVE" },
    "updated_manager_profile": { "id": "7bd99d76-...", "status": "ON_CALL" }
  },
  {
    "incident_manager_profile": { "id": "839b82da-...", "status": "INACTIVE" },
    "updated_manager_profile": { "id": "839b82da-...", "status": "ON_CALL" }
  }
]

The for loop iterates through each ticket, it finds the incident manager for the ticket and updates the status of the incident manager to ON_CALL