Delivery signals your billing and CRM can actually rely on.
A single, versioned event contract for every delivery signal that matters. Signed and verifiable on receipt, retried on a schedule you can predict, and replayable from Activity when a downstream system was down.
The retries pulled the whole table out of sync.
You wired Stripe events to your billing table with confidence. Then you tried to wire your ESP’s delivery events to your CRM, and every retry pulled the whole delivery-status table out of sync. Signed webhooks — the kind you know work — turned out to be a Business-tier feature. So you built a dedupe layer, a signature shim, and a replay tool from scratch, and every one of them is a page in the on-call runbook now.
One event contract. One signature. One replay button.
Every workspace gets the same event stream, versioned so a schema change never lands without warning, signed with a per-endpoint secret so your receiver can verify the payload without an SDK, and de-duplicated by event id so the retry contract cannot corrupt your database. When a downstream system was down, you replay the missing window from Activity — a checkbox and a button, not a script.
The delivery events you get — every plan.
No feature-gated events. No add-on SKU. If a message moves, an event fires.
How the retry contract actually behaves.
Signature verification without an SDK.
Every event is signed with a secret unique to the receiving endpoint, and the signature travels alongside the payload with a timestamp. A compromised secret on one endpoint never compromises the others, and a rotated secret takes effect on the next event with no downtime. The verification recipe is a few lines in any language — hash the payload with your secret, compare in constant time, reject anything older than your accepted window. No client library required.