book
Hey Vapi team – looking for guidance on a tool + identity issue.
Context
We use Vapi for an AI Voice SDR that calls users after they request a demo.
Calls are triggered via n8n and include prospect identity in metadata:
metadata.email
metadata.firstName
metadata.lastName
If the user chooses a time, the assistant calls a custom bookMeeting tool, which POSTs to an n8n webhook that books a HubSpot meeting.
What works
Posting directly to the /book-meeting webhook via Postman with:
email
firstName / lastName
etc
works perfectly and sends the calendar invite to the prospect.
The problem
When bookMeeting is triggered from Vapi during a real call, the payload sometimes contains internal Workleap SDR details (eg. Natalia or Marissa) instead of the prospect.
This often happens after the user answers the “how many employees” question (eg. “50 employees”), which we only intend to use for routing logic.
Example call log where this happened: 019b2470-6e5a-7dd2-b448-7e836ced2a9a
Response we received (actual payload):
{
"email": "marissa.likoudis@workleap.com
",
"firstName": "Marissa",
"lastName": "Likoudis",
"timezone": "America/Los_Angeles",
"startMillisUtc": 1765895400000,
"durationMillis": 900000
}
Response we expected (prospect identity from metadata):
{
"email": "ewan.stott@workleap.com
",
"firstName": "Ewan",
"lastName": "Stott",
"timezone": "America/Los_Angeles",
"startMillisUtc": 1765895400000,
"durationMillis": 900000
}
What we suspect
bookMeeting requires email / name, and if the model is uncertain it may fall back to defaults or inferred identities.
We’ve removed default values but still see this intermittently.
Questions
Is there a recommended way to force tool args to come only from call metadata?
What happens in Vapi if a required tool arg is missing or unclear?
Is there a best practice for passing a stable call or session identifier into tools so downstream systems can safely rehydrate identity?
Any guidance would be really appreciated – thanks!
Context
We use Vapi for an AI Voice SDR that calls users after they request a demo.
Calls are triggered via n8n and include prospect identity in metadata:
metadata.email
metadata.firstName
metadata.lastName
If the user chooses a time, the assistant calls a custom bookMeeting tool, which POSTs to an n8n webhook that books a HubSpot meeting.
What works
Posting directly to the /book-meeting webhook via Postman with:
firstName / lastName
etc
works perfectly and sends the calendar invite to the prospect.
The problem
When bookMeeting is triggered from Vapi during a real call, the payload sometimes contains internal Workleap SDR details (eg. Natalia or Marissa) instead of the prospect.
This often happens after the user answers the “how many employees” question (eg. “50 employees”), which we only intend to use for routing logic.
Example call log where this happened: 019b2470-6e5a-7dd2-b448-7e836ced2a9a
Response we received (actual payload):
{
"email": "marissa.likoudis@workleap.com
",
"firstName": "Marissa",
"lastName": "Likoudis",
"timezone": "America/Los_Angeles",
"startMillisUtc": 1765895400000,
"durationMillis": 900000
}
Response we expected (prospect identity from metadata):
{
"email": "ewan.stott@workleap.com
",
"firstName": "Ewan",
"lastName": "Stott",
"timezone": "America/Los_Angeles",
"startMillisUtc": 1765895400000,
"durationMillis": 900000
}
What we suspect
bookMeeting requires email / name, and if the model is uncertain it may fall back to defaults or inferred identities.
We’ve removed default values but still see this intermittently.
Questions
Is there a recommended way to force tool args to come only from call metadata?
What happens in Vapi if a required tool arg is missing or unclear?
Is there a best practice for passing a stable call or session identifier into tools so downstream systems can safely rehydrate identity?
Any guidance would be really appreciated – thanks!
