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

# Webhooks

> Send HTTP notifications to an external system when Gapstack resources change.

Use a webhook to notify an external system when something changes in Gapstack. You choose the events and an HTTPS endpoint. Gapstack sends a **POST** request to that URL when one of those events occurs.

You can use the payload to start a pipeline, update another system, or trigger any automation that should run after a change in Gapstack.

You can set up webhooks at the **project** level or the **environment** level. Open **Webhooks** on the project or on the environment, depending on where you want the subscription.

<Frame caption="Choose events and an endpoint, then click Activate Webhook.">
  <img src="https://mintcdn.com/gapstack/L3fhphtn-SKTlfU9/images/webhooks.png?fit=max&auto=format&n=L3fhphtn-SKTlfU9&q=85&s=c0e88845304d18dd151fb25c30ae0a54" alt="Environment Webhooks tab with project, environment, and AWS account events, plus an endpoint URL field and Activate Webhook." width={3269} height={2219} style={{ width: "720px", maxWidth: "100%", height: "auto" }} data-path="images/webhooks.png" />
</Frame>

## Events

Select at least one event.

| Event                          | Key                          | When it fires              |
| ------------------------------ | ---------------------------- | -------------------------- |
| **Project Updated**            | `project.updated`            | A project is updated       |
| **Project Deleted**            | `project.deleted`            | A project is deleted       |
| **Environment Created**        | `environment.created`        | An environment is created  |
| **Stack AWS Account Linked**   | `stack.aws.account.linked`   | An AWS account is linked   |
| **Stack AWS Account Unlinked** | `stack.aws.account.unlinked` | An AWS account is unlinked |

## Add a webhook

<Steps>
  <Step title="Open Webhooks">
    Open a **project** or an **environment**, then click **Webhooks**.
  </Step>

  <Step title="Choose events">
    Select the events that should notify your system.
  </Step>

  <Step title="Enter the endpoint">
    Enter the HTTPS URL that should receive the POST request, such as `https://example.com/webhook`.
  </Step>

  <Step title="Activate">
    Click **Activate Webhook**. Gapstack starts sending POST requests to the endpoint for the events you selected.
  </Step>
</Steps>

<Note>
  Your endpoint must accept POST requests and return a success status. If the endpoint is down, Gapstack cannot deliver the event.
</Note>