What Is a Webhook?

The Short Version

A webhook is an automatic notification between two systems. When something happens in System A, it immediately tells System B: “Hey, this just happened.”

No human involved. No copying and pasting. No waiting for a scheduled sync.

How It Works

Think of it like a doorbell. You don’t stand at the door checking every five seconds whether someone’s there. The doorbell rings when someone arrives, and you respond.

Webhooks work the same way:

You tell System A: “Whenever a new form submission comes in, send the details to this address”
System A watches for that event
When it happens, System A sends a message (a small package of data) to System B instantly
System B receives the data and does something with it — creates a record, sends an email, updates a deal

The whole thing takes less than a second.

Real Examples

Here are webhooks doing real work in businesses we’ve built integrations for:

Form submitted, CRM updated. Someone fills out a contact form on your website. A webhook fires and creates a new contact in HubSpot with their name, email, and what they asked about. No one had to re-type anything.
Call missed, SMS sent. Your phone system detects a missed call. A webhook triggers an automated text message: “Sorry we missed your call. We’ll get back to you shortly.” The missed call is also logged in your CRM.
Deal closed, invoice created. A salesperson marks a deal as won in Pipedrive. A webhook tells Xero to create a draft invoice with the client’s details and the deal amount pre-filled.
Appointment booked, calendar synced. A client books a meeting through your scheduling tool. A webhook pushes the appointment into your project management system and assigns a team member.

Why It Matters for Integration

Without webhooks, the only way to keep two systems in sync is polling — checking every few minutes: “Anything new? Anything new? Anything new?” That’s slow, wasteful, and can miss things between checks.

Webhooks make integrations:

Instant — data moves in real time, not on a 5-minute delay
Efficient — systems only talk when something actually happens
Reliable — when built properly, webhooks confirm delivery and retry on failure

What You Need to Know as a Business Owner

You don’t need to set up webhooks yourself. That’s our job. But understanding the concept helps when we explain how your integration works:

If we say “the webhook fires when a deal moves to Closed Won,” you’ll know that means the system reacts instantly to that specific event
If something seems delayed, “Is the webhook working?” is a useful question to ask
If you change a process in one system (rename a field, add a stage), it may affect the webhook — let us know so we can adjust

Next Steps

Now that you know what a webhook is, read What Is an API? to understand the other half of how integrations work. Or visit API Integration Services to see how we put these pieces together for clients.