> ## Documentation Index
> Fetch the complete documentation index at: https://docs.spark360.io/llms.txt
> Use this file to discover all available pages before exploring further.

# HTTPS Enforcement

> Endpoint URL requirements for Spark360 webhook subscriptions.

Spark360 requires HTTPS webhook endpoints and rejects insecure URLs at create and edit time.

<Warning>
  Any `endpoint_url` that does not begin with `https://` is rejected.
</Warning>

## Secret handling notes

* Signing secrets are generated at subscription creation
* Secrets are stored in Supabase Vault
* Subscription rows store only the Vault UUID reference
* Secret regeneration immediately invalidates the previous secret