Why not call Calendly's API directly from your own endpoint? You can — but then you own Calendly's signature verification, retry handling, and payload quirks yourself. ZestyGlue verifies the signature, normalizes the event into a clean JSON body, and POSTs it to your URL — you only write the part that's actually yours.
What it looks like
ZestyGlue
Calendly — Invitee · Created
A real Calendly event, shown as ZestyGlue formats it for Custom Webhook.
Setup — about two minutes
- Create the connector. In ZestyGlue, start a new Calendly → Custom Webhook connector. You'll get a unique webhook URL right away.
- Point Calendly at it. Calendly's webhook subscriptions are created via their API (or the Integrations panel on Enterprise plans) — create one pointed at your ZestyGlue webhook URL.
- (Optional) copy the signing key. Calendly returns a signing key when you create the subscription — paste it into ZestyGlue for extra verification, though it isn't required to get started.
- Point it at your endpoint. Paste the URL of your own server, script, or automation tool's webhook receiver — no signup, no app to install.
Under the hood: Calendly's webhook signing key is only returned once, at the moment you create the webhook subscription via their API — copy it into ZestyGlue immediately, since Calendly won't show it again.
Events you can forward
invitee.created
invitee.canceled
Questions
Is my Calendly Webhook Signing Key safe with ZestyGlue?
It's encrypted at rest with Fernet symmetric encryption before it ever touches disk, it's never logged, and it's never displayed again in the dashboard after you enter it — only a masked placeholder is shown.
Does this notify on cancellations as well as new bookings?
Yes — subscribe to both invitee.created and invitee.canceled if you want to see cancellations alongside new bookings.
Do I need a paid Calendly plan to use webhooks?
Calendly requires at least a paid plan to create webhook subscriptions via their API — the free plan doesn't expose this feature.
Do I need to write my own server to receive this?
Yes — this destination expects your own endpoint (or a tool like a serverless function, a script, or another automation platform's webhook trigger) to receive the POST. If you don't have one yet, pick one of ZestyGlue's built-in destinations instead.
What happens if my ZestyGlue subscription lapses?
Events are silently dropped rather than causing errors on Calendly's side — Calendly never sees a failure response, so it won't retry aggressively or flag your webhook as broken. Your dashboard will simply stop showing new events until you resubscribe.