A hook is your function that WBAMS calls when something happens. Hooks are the kind of customization an update never overwrites.
- Service lifecycle
- Created, activated, suspended, terminated, canceled, renewed, upgraded; for services and add-ons.
- Billing
- Invoice created, paid, refunded; late fees; transactions.
- Orders
- Placed, accepted, fraud outcome, canceled, deleted.
- Clients
- Registration, edits, sign-in and sign-out, closure.
- Support
- Ticket opened, replied, status changed, closed.
- Output
- Inject markup into the head, header or footer of either area.
- Automation
- Before and after the daily run and its tasks.
- Put hooks in your add-on's hooks file, not in a product file.
- Give functions distinct names; two of the same name is a fatal error.
- Queue slow work: a hook runs inside the request that triggered it.
- Catch your own errors; an exception escaping a hook stops what called it.
Full guide
The complete reference is Hooks in the WBAMS documentation.