Webhooks

Signed event deliveries — sync your app in real time instead of polling. Buffer's biggest gap, closed.

Events

Parameter	Type	Description
update.sent	event	A scheduled or instant update was accepted by the network (this is the billable moment)
update.failed	event	The network rejected the update — payload includes the reason
update.created	event	An update was queued (create call succeeded)
update.approved	event	A pending update passed the approvals workflow
channel.connected	event	A network was connected to the workspace
channel.schedule_updated	event	Time slots changed
quota.exceeded	event	Successful-post quota hit on a hard-capped plan

Payload & signature

X-BufferSass-Event: update.sent
X-BufferSass-Signature: sha256=1f3a…

{
  "event": "update.sent",
  "data": {
    "id": "upd_7c2…", "channel_id": "cha_9a1…",
    "service": "x", "text": "Ship day! v2.4 is live 🚀",
    "sent_at": "2026-11-10T14:30:02Z"
  }
}

POST to your endpoint

import crypto from "crypto";

export function verify(req) {
  const raw = req.rawBody; // exact bytes
  const expected =
    "sha256=" + crypto.createHmac("sha256", process.env.WH_SECRET).update(raw).digest("hex");
  return crypto.timingSafeEqual(
    Buffer.from(expected), Buffer.from(req.headers["x-buffersass-signature"]));
}

verify the signature (Node)

Reliability

Deliveries are real outbound POSTs with signed headers (X-BufferSass-Event, X-BufferSass-Delivery, X-BufferSass-Signature) and log to the dashboard (Webhooks → deliveries) with the response status code (0 = endpoint unreachable).
Non-2xx responses retry with backoff (up to 3 attempts) on Starter plans and above.
Replay any delivery from the dashboard while debugging.
Buffer reports live delivery failures. Sync from Buffer to see the failure message and retry the post in Buffer.