Create custom events for webhooks in Label Studio - Label Studio

If you want to trigger custom events for webhooks in Label Studio, you can extend the webhook event model.

Create a custom webhook event

To create a custom webhook event, add your own action to the WebhookActions model.

For example:

python

class WebhookAction(models.Model):
    ...
    SOMETHING_HAPPENED = 'SOMETHING_HAPPENED'
    ...
    ACTIONS = {
        SOMETHING_HAPPENED: {
            'name': _('Something happened'),
            'description': _("A thing happened. We wanted to let you know."),
            'key': 'something',
        },
        ...
    ...

After declaring the action and the associated properties and payload details in the WebhookAction class, call the event action in the code where it occurs. For example:

...python
result = do_something()
emit_webhooks(organization, WebhookAction.SOMETHING_HAPPENED, {'something': [result]})
...

You can retrieve the organization details using Organization.objects.first().

Call event actions with Python functions

There are several functions you can use to call event actions. Refer to the following table:

Python function	When to use	Additional details
`get_active_webhooks()`	Get all active webhooks.
`run_webhook()`	Run one webhook and pass some payload.
`emit_webhooks()`	Send requests for all webhooks for an action.
`emit_webhooks_for_instances()`	Send serialized instances with webhook requests.	You must declare a `serializer` in the `WebhookAction.ACTIONS` model.

Call event actions with decorators in API source code

You can use decorators with the CRUD REST methods to send event actions to webhooks. You can use the following:

Decorator syntax	When to use	Details
`@api_webhook()`	`POST`/`PUT`/`PATCH` requests	Expects a response with an `id` and uses the `.get_object()` function after the request to send that information.
`@api_webhook_for_delete()`	`DELETE`	Sends only the `id` field after a successfully delete operation.