Webhook Connect ships in the Pro Pack and is the connection to reach for when the app you need has no native connector.
As a source:
WP Sync gives you a unique inbound endpoint URL. Paste that URL into the other system's webhook or notification settings, and every POST that arrives becomes a contact fed into the bridges you attached to it. This makes almost any modern SaaS product a source, because virtually all of them can send a webhook.
As a destination:
Each contact is fired out as an outbound POST to a URL you choose. That covers Zapier, Make, n8n, a custom endpoint on another server, or an internal API of your own. It is push, so it fires as part of the bridge run.
What WP Sync does with an unfamiliar payload:
The engine reads the email and name fields it can recognise, and remembers the other field keys the payload contained. Once a payload has arrived, those keys become available to you as filter fields and as tokens in custom field values and tag names, including keys written with dots for nested structures.
Why the inbound endpoint is safe to publish:
The URL contains a per app secret token. A request without the right token is rejected, and a request for a connection that has been disconnected is acknowledged quietly rather than erroring.
Behaviour that stops broken integrations:
A GET request answers with a success, because many platforms verify a URL before they will save it. Test pings and event types the connector ignores also answer with a success, so the other platform never disables the webhook for what it thinks is a failure.
Related built in behaviour:
The thirteen push capable built in autoresponders use the same inbound mechanism on their own private endpoints, which is why they can be sources without any polling.