Code Extension
Sometimes the conversational flow steps behavior needs to align to more complex business rules that cannot be implemented at design time using the graphical Flow Designer. For example, a hero step should present different buttons with options for each specific user role and conditions. It is very difficult to address dozens of combinations by using the Flow Designer.
Code Extension is a powerful feature that enables you to make hard-coded adjustments to flow steps definition.
To hard-code a flow step, on the desired flow step, click the Code Extension section header, then click the Edit icon displayed next to the desired language (if there are AI Agent additional languages set on the AI Agent). The Code Extension editor appears.
The Code Extension provides you with a set of predefined code templates to help you define your JavaScript code.
To add a template, click the Add default template button (
) and select the template that best suits your needs.
thisStepValidator.Validate(thisStep); at the end of your code. This ensures that the flow step code is validated before execution, helping to prevent errors and ensure smooth functionality.Use cases for Flow step code extensions
Conditional menus
Example: Show a different menu for Authenticated users
(
function ()
{
thisStep.Message = 'This message replaces this: ' + thisStep.Message;
//Clear all cards and build new ones.
//It is a good practice to author with the designer all the options, and customize with code specific rules.
thisStep.Metadata.PostActions?.Clear();
//use create* methods to create various objects.
if ([[ChatUser]].IsAuthenticated)
{
//create first card with two buttons
thisStep.Metadata.Hero.Cards.Add (thisStep.CreateHeroCard());
thisStep.Metadata.Hero.Cards[0].Title = "Title 1";
thisStep.Metadata.Hero.Cards[0].Subtitle = "Sub title 1";
thisStep.Metadata.Hero.Cards[0].Text = "Decsription 1";
//need to create the collection first
thisStep.Metadata.Hero.Cards[0].Buttons = thisStep.CreateCardActionList();
thisStep.Metadata.Hero.Cards[0].Buttons.Add(thisStep.CreateCardAction());
thisStep.Metadata.Hero.Cards[0].Buttons[0].Title = "Option 1";
thisStep.Metadata.Hero.Cards[0].Buttons[0].Value = "Value 1";
thisStep.Metadata.Hero.Cards[0].Buttons.Add(thisStep.CreateCardAction());
thisStep.Metadata.Hero.Cards[0].Buttons[1].Title = "Option 2";
thisStep.Metadata.Hero.Cards[0].Buttons[1].Value = "Value 2";
}
// this is mandatory at the end
thisStepValidator.Validate(thisStep);
}
)();
The figure below shows a hero step definition in Flow Designer using the code extension above.
Conditional messages
(
function ()
{
if ([[Account]].CasesCount >0)
{
thisStep.Message = 'Alert! :('/*sad emoticon*/+ thisStep.Message;
}
else
{
thisStep.Message = 'Info :)'/*smile emoticon*/+ thisStep.Message;
};
thisStepValidator.Validate(thisStep);
}
)();
The figure below shows a message step definition in Flow Designer using the code extension above.
Data Manipulation
The Set object allows you to store unique values of any type. You can use it to deduplicate data retrieved during a flow or to quickly check if a specific value exists within a large list. This ensures that the data being passed back to the AI Agent is clean and free of redundant entries.
Syntax
new Set([iterable]);
Example
This example demonstrates using a Set object to filter out duplicate product IDs collected during a conversation before saving them to a Flow Variable.
Example
(function main() {
// Simulated list of IDs collected from user input or an API
const rawProductIds = ["P100", "P200", "P100", "P300", "P200"];
// Create a Set object to automatically remove duplicates
const uniqueIdsSet = new Set(rawProductIds);
// Convert back to an array for compatibility with Flow Variables
const finalProductList = Array.from(uniqueIdsSet);
// Save the cleaned list to the <span class="mc-variable General.AI_Agent variable">AI Agent</span> flow context
Context.SetFlowVariable("UniqueProductList", finalProductList.join(", "));
// Log the result for debugging in the Audit Log
Context.LogRequestTask("Deduplicated product list created:" + uniqueIdsSet.size + " items.");
})();
Code Extension – Error Handling
You can configure the behavior of the conversational engine when encountering an error during code extension execution. This setting controls whether the conversation continues or stops when an error is detected while executing the code provided in Code Extension on a flow step.
When an error occurs, Druid can either skip it silently or raise an exception in the Conversation History, similar to how connector errors are handled.
To configure error handling for Code Extension:
- Go to the AI Agent details > Dialogue management.
- From the Set variable error severity drop-down, select one of the following options:
- Silent – Skips the error and continues the conversation. This was the default behavior in previous releases.
- Raise exception – Triggers an exception and records the error in the Conversation History. Use the Raise exception option to detect configuration issues early and prevent code execution errors during conversations.
- Save the configuration.
For steps that have the Error Handler set, you can author how the error is handled in the conversation. Additionally, you can create a flow dedicated to error handling and select it from AI agent details > Dialogue management section, Exception flow drop-down.


