> For the complete documentation index, see [llms.txt](https://docs.clockworkhq.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.clockworkhq.com/outgoing-webhooks.md).

# Outgoing Webhooks

## Introduction

Outgoing webhooks enable an external application (controlled by you) to be notified when an event happens within the Clockwork ecosystem. Examples include when an invitation email is sent to a customer, or when a new study is launched.

Once you have subscribed to an event, we will send an HTTP `post` request to a URL that you supply, with an attached payload of metadata about the event

## List of Webhooks supported

Currently, the only events we support for outgoing webhooks are:

`invitation_sent`- Triggered when an appointment invitation email is created and sent

The payload for `invitation_sent`:

```
event_name - The name of the webhook
uuid - The unique identifier for this webhook in Clockwork
sub_uuid - The unique identifier for your instance of this webhook in Clockwork
customer_uuid - The unique identifier for this customer in Clockwork
customer_email - The email of the customer
customer_first_name - The customer's first name
customer_last_name - The customer's last name
customer_attributes - The current list of all attributes of the customer
customer_last_contacted_at - A timestamp of when the customer was last contacted
```

## Example

Let's say you want to use the `invitation_sent` webhook. First, you would contact us and let us know the name of the event (`invitation_sent`), and the URL where we should send the event, e.g. `https://youdomain.com/webhooks/webhook_name`. Once set up, you'll start receiving `POST` requests to the url you specified, with the payload that was detailed above.