Session variables

Gatekeeper sends the current event in the form of session variables. Session variables are saved independently for each call session, and every variable is identified uniquely by a key. The variables include:

• Current event type
• Values attached to the current event
• Previously collected biometric results and telephony information
• Flow configuration
• Additional variables that reflect the current state of the flow

When a session variable is added or changed, the flow generates a SESSION_VARIABLE_UPDATE event, giving the webhook the opportunity to change the flow’s behavior as the flow updates its internal state.

Because every webhook execution comes with the full copy of the call’s session variables, the webhook does not need to maintain its state in its own session storage.

Still, there are some limitations about what a webhook can store in the session variables, for security and performance reasons:

• The webhook cannot store more than a few kilobytes of its own session variables
• Some session variables’ values cannot be modified by the webhook.