You can have multiple Webhook Nodes for a single Voice Agent, if you want to sync the result of the call at multiple places.
A Webhook Node fires when it is reached inside a workflow and sends a payload you template here. If instead you want signed, agent-level notifications when a call starts, ends, and is analyzed, configure event webhooks in Webhook Settings тАФ that is a separate mechanism.

Creating the Webhook Payload

The payload can contain a valid JSON, and you can reference variables while constructing that payload. You can reference below variables while constructing the payload.
  • {{workflow_run_id}} Unique ID of the Agent run
  • {{workflow_id}} ID of the Agent
  • {{workflow_name}} Name of the workflow
  • {{campaign_id}} ID of the campaign this run belongs to (empty for ad-hoc runs)
  • {{call_time}} ISO-8601 UTC timestamp of when the call was initiated
  • {{initial_context.*}} Initial context variables
  • {{gathered_context.*}} Extracted variables
  • {{cost_info.call_duration_seconds}} Call duration
  • {{recording_url}} Call recording URL
  • {{transcript_url}} Transcript URL
For the full list of available variables, authentication options, and receiver examples, see the Webhook Payloads developer reference. An example of the payload is given below