# Webhook
URL: /reference/blocks/trigger-webhook
Type: reference
Description: Trigger workflow via HTTP webhook
Keywords: webhook, trigger/webhook, triggers, trigger, block, workflow builder
`trigger/webhook` — Trigger workflow via HTTP webhook.

Where it appears [#where-it-appears]

The **Webhook** block is a trigger — it starts a workflow. Add it from the **Triggers** group in the Workflow Builder.

Fields [#fields]

| Field           | Type        | Required | Default | Description                                                                                                                                          |
| --------------- | ----------- | -------- | ------- | ---------------------------------------------------------------------------------------------------------------------------------------------------- |
| `webhookUrl`    | text        | No       | —       | The unique URL that triggers this workflow when called with an HTTP POST. Copy and paste it into the external service that should fire the workflow. |
| `webhookSchema` | JSON schema | No       | —       | Declare the expected shape of the incoming request body. Defined fields become typed outputs available for downstream references.                    |
| `testInput`     | code        | No       | —       | Sample JSON payload to use when running this workflow in test mode instead of waiting for a real webhook call.                                       |

Inputs and outputs [#inputs-and-outputs]

Inputs are the configurable fields above. The block produces these outputs:

**Outputs**

Reference an output downstream with `<Webhook.field>`.

| Name        | Type    | Description           |
| ----------- | ------- | --------------------- |
| `triggered` | boolean | Whether trigger fired |
| `timestamp` | number  | Trigger timestamp     |

Related [#related]

* [All workflow blocks](/reference/blocks)
* [Workflow Builder overview](/workflow-builder-overview)