FAST Action Attributes

Actions can be configured with custom attributes that are included in the FAST message.

Attributes may be:

• Static Attributes – fixed values configured on the action. These can be unique identifiers and flags that are relevant to the consumer of FAST.
• Dynamic Attributes – values populated at runtime, such as the Tree ID or Rule ID responsible for triggering the action.

These attributes allow additional context to be provided to downstream systems where required.

Rule-level traceability using dynamic attributes

Where clients require visibility into exactly which rule triggered an action, dynamic attributes can be assigned to the action.

Common examples include:

• Tree ID
• Rule ID

When these attributes are included, the FAST message can provide direct traceability between the action and the rule evaluation that triggered it.

For example, a decline action may be linked to multiple rules. Under normal circumstances, the action would appear only once in the FAST message. However, if Tree ID or Rule ID dynamic attributes have been assigned to the action, separate action entries may be included, allowing downstream systems to identify the specific rule evaluation responsible for each action.

Example FAST excerpt

In this example the same decline action with a dynamic ruleID attribute was assigned to 2 separate rules which both triggered the action.

"DECISION_ENGINE": {
    "Actions": [
      {
        "id": "5",
        "typeName": "DECLINE",
        "details": {
          "attributes": [
            "ruleID": "123"
          ]
        }
      },
      {
        "id": "5",
        "typeName": "DECLINE",
        "details": {
          "attributes": [
            "ruleID": "567"
          ]
        }
      },
    ],
    "DryRunActions": []
  }