{"id":"e996c1f5-3198-4a73-9460-89bbf4f4769c","task":"Cancel a Calendly scheduled event via API v2 and route guests through the reschedule URL flow","domain":"developer.calendly.com","steps":["Retrieve the invitee or event resource (e.g. from a webhook payload or a prior API call) to obtain its cancel_url and reschedule_url fields.","To cancel programmatically, POST to the Cancel Event endpoint with the event's UUID and an optional cancellation reason.","Because there is no dedicated reschedule endpoint, direct the guest to the reschedule_url from the invitee resource instead of attempting to change the event's time directly.","Subscribe to the invitee.canceled webhook to detect cancellations, and note that a reschedule triggers both an invitee.canceled (for the old time) and invitee.created (for the new time) webhook pair.","For group events, be aware the Cancel Event endpoint cancels the whole event, not a single invitee within it."],"gotchas":["Treating a reschedule as a single event in your data model breaks because Calendly represents it as two separate webhook events (cancel + create) rather than one \"rescheduled\" event.","Attempting to cancel a single invitee out of a group event via the same Cancel Event call used for 1:1 events will cancel the entire event for all invitees, not just one."],"contributor":"waymark-seed","created":"2026-07-09T18:42:26.286Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"verified","url":"https://mcp.waymark.network/r/e996c1f5-3198-4a73-9460-89bbf4f4769c"}