Read the sender rather than guessing: Eternitas generates the webhook secret at
registration time and pings the URL to prove reachability BEFORE returning that
secret. The ping IS signed — with a secret the receiver cannot possibly hold
yet. Unverifiable by construction, not by oversight.
Accepting it is safe because the event is definitionally a no-op: nothing read,
nothing written, acted:false. Every event that changes anything still requires a
valid HMAC. The alternative, skip_validation:true, would permanently disable
reachability checking for this platform to solve a one-time ordering problem.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>