A webhook works like a notification between software applications. Instead of constantly asking an application whether anything is new, you give it an address: when an event occurs, it sends a message there describing what happened. The term was proposed in 2007 by developer Jeff Lindsay (his original post), from the “hook”, an attachment point built into a program.
A concrete example
A visitor leaves their contact details with an estate agency’s assistant. A message immediately goes to the agency’s CRM (customer relationship management system) with their name, phone number, the property they are interested in and a link to the conversation. The CRM creates the record and assigns it to the relevant agent, without anyone copying anything manually.
Useful events around an AI assistant
- A new contact: it goes to the CRM or prospecting tool
- A request for human handover: a notification arrives in Slack or Teams
- A closed conversation: its summary goes to the ticketing tool
- Completed lead qualification: the full request enters the sales follow-up process
What makes a webhook reliable
A well-designed webhook is signed with a shared secret so the receiving tool knows it comes from the expected sender. A failed delivery (the tool is under maintenance, the network drops) is retried later at increasing intervals, then marked as failed for review. Every attempt is logged: it is clear what was delivered, when and what failed. In KernChat, every message carries an HMAC-SHA256 signature, and a failed delivery is retried after 1, 5, 30, 120 and then 720 minutes, making six attempts in total.
Webhook or API: what is the difference?
An API (application programming interface) responds when queried; a webhook sends a notification on its own when something happens. The two complement each other: the webhook announces the event, and the receiving tool can then query the API for more details.
KernChat sends these events to the organization’s tools (CRM, ticketing tool, Slack or Teams), within the limits it sets (see the features).