Library / AI & automation / Webhook
No. 066·noun·also called callback URL, event notification, HTTP callback

Webhook

A way for another service to notify your app the moment something happens, instead of your app checking repeatedly.

SPECIMEN · DIAGRAM · FLOW
ServiceStripepayment succeeded
AppYour webhookverify + handle
DataInvoices
ServiceReceipt email
eventmark paidsend
Definition

What it is

A webhook is an address your app gives to another service so it can send a message when an event happens: Stripe tells you a payment succeeded, a form tool tells you a submission arrived, GitHub tells you code was pushed.

It's the reverse of calling an API. With an API, your app asks "anything new?"; with a webhook, the other service rings your doorbell.

When you ask for one, name the service, the event, and what your app should do when it arrives.

Say it like a builder

How to ask for it

Vague

“When someone pays, update their account.”

Precise

“Add a Stripe webhook for the "payment succeeded" event: when it arrives, verify its signature, mark the matching invoice Paid, and email the customer a receipt.”

Why it works

"When someone pays" doesn't say how the app finds out; naming the webhook and the event pins down the trigger.

In the wild

You've seen this in

  • SStripe notifying a store that a payment cleared
  • TTypeform sending new responses to a CRM
  • SShopify telling a warehouse app about a new order
Usage note

Often confused with

APIWith an API your app asks; with a webhook the other service tells you.Cron jobA cron job runs on a schedule; a webhook runs when an outside event happens.