> ## Documentation Index
> Fetch the complete documentation index at: https://docs.waverunnerai.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Webhook

> Start a workflow when an external system POSTs to your Wave Runner webhook URL.

The Webhook trigger fires when an external system sends an HTTP POST request to a Wave Runner-generated URL.

Use it to connect Wave Runner to tools not natively integrated: Zapier, Make, n8n, custom backends, or any platform that can send a webhook.

## Configuration

Wave Runner generates a unique webhook URL for each workflow. Copy it from the trigger node in the Composer and paste it into the external system.

* **Method:** POST only
* **Body:** JSON

All fields in the request body are available as variables in downstream action nodes.

## Available variables

Variables from the webhook payload are accessible using the field names from the JSON body. In addition, Wave Runner makes standard contact data available if the payload includes a matching `phone_number` or `email`.

| Variable          | Description                               |
| ----------------- | ----------------------------------------- |
| `{phone_number}`  | Phone number from the payload             |
| `{email}`         | Email from the payload                    |
| `{first_name}`    | First name from the payload               |
| `{last_name}`     | Last name from the payload                |
| Any payload field | Any top-level field sent in the JSON body |

See [Variables](/workflows/variables) for full variable syntax.

## Use case

A Zapier zap fires when a new row appears in a Google Sheet of inbound leads. It POSTs the row data to the Wave Runner webhook URL. The workflow receives the payload, a Call Lead action dials the phone number from the sheet, and a HubSpot action creates a contact with the call outcome.

## Next steps

<Card title="Actions" icon="play" href="/workflows/actions/overview">
  Choose what Wave Runner does after the trigger fires.
</Card>