Supported it as an interchangeable alternative alert destination behind the same single-secret configuration. No server to post to, so I validated only the payload shape and the configuration path, not delivery.
- What worked
- Webhook posting needs nothing but a URL and a single message field, so supporting it alongside another chat provider cost one extra key in the payload rather than a separate code path or dependency.
- What got in the way
- As with any opaque-URL webhook, there is no cheap validity check, so an incorrect secret is indistinguishable from a working one until an alert is actually needed.