[🐛 Bug]: Webhook provider uses dummy payload for validation

[yosizelensky]

Describe the bug
Using a dummy test payload is bound to fail on a lot of webhooks, since it'll be a non 200 response. We should just validate the url.

To Reproduce
Steps to reproduce the behavior:

1. Have a webhook that expects a specific payload schema.
2. Fail to install the webhook.

Expected behavior
The webhook installation should not fail.

[dosubot]

Hi @yosizelensky! I'm Dosu and I’m helping the keep team.

You're right—Keep's webhook provider currently validates webhook URLs by sending a dummy payload ({"test": "payload"}) and expects a successful (typically 200) response. If the webhook requires a specific payload schema, this test will fail and prevent installation, even if the URL is otherwise valid. There isn't a configuration option or alternative flow for URL-only validation; the code always sends a test payload as part of validation, and only checks that the URL isn't blacklisted—not that it's reachable without a payload. This means webhooks with strict schema requirements can't be installed unless they accept the dummy payload during validation. See implementation.

To reply, just mention @dosu.

---

^{How did I do? Good | Irrelevant | Incorrect | Verbose | Hallucination | Report 🐛 | Other}