Webhook Triggers

Webhook triggers give you a unique URL that external services can call to start a Nebula automation. Any service that can send an HTTP POST request can trigger a workflow — no OAuth required.

What webhook triggers are good for

Here are a few examples:

• Your CI/CD pipeline posts to a Nebula webhook when a deployment completes, and Nebula posts a summary to Slack.
• Your website form submissions are sent to a Nebula webhook, and Nebula creates a CRM record and sends a welcome email.
• A monitoring service calls a Nebula webhook on an alert, and Nebula notifies your on-call team.

Creating a webhook trigger

https://nebula.gg/webhooks/your-unique-token

You can also create a webhook trigger through chat:

You

Create a webhook trigger that posts a deployment summary to #engineering whenever it receives a payload.

Create Trigger

Creating webhook trigger for deployment notifications.

Nebula

Done! Here's your webhook URL. Configure your CI/CD pipeline to POST to this URL when a deployment completes, and I'll summarize the payload and post it to #engineering.

Security

Webhook triggers support two authentication methods:

• HMAC signature — the external service signs its request with a shared secret, and Nebula verifies the signature using the X-Webhook-Signature header.
• Shared secret — a simpler approach where the external service includes a secret token in the X-Webhook-Secret header.

Nebula validates incoming requests and rejects any that don't match the expected signature or secret.

Using the webhook payload

The data sent in the webhook POST body is available to your task as context. For example, if a webhook carries a payment event with an amount and customer_email, your task steps can reference those values.

You can also add a filter to the webhook trigger so it only runs the task when the payload meets certain conditions — for example, only process webhook events where status equals completed.