subscription.* events

A cancelling member said why they are leaving.

When this fires

A member reached the cancellation screen, on the portal or in a connector chat, and answered the question the project asks on the way out: a reason from the fixed list and, if they wrote one, a sentence of their own. It fires the moment the reason is recorded, before the member sees the offer or confirms, so a member who then takes the offer and stays still appears here. The creator is alerted at the same time. A project that switched the question off asks nothing and fires nothing; its offers are still counted, through subscription.offer_taken and the cancellation records.

Related events

  • subscription.offer_taken: the member took the offer instead of cancelling.
  • subscription.cancelled: the member went on and cancelled.
postWebhooksubscription.cancellation_feedback

Headers

SB-Signaturestring required

t=<unix seconds>,v1=<hex>: the HMAC-SHA256 of "<t>.<raw body>" under the endpoint's secret. Verify it before acting, and refuse a t more than 300 seconds from now. During a secret rotation a v0= signature under the previous secret may precede v1=.

SB-Event-Idstring required

The event's ULID, bare. The envelope's id is the same ULID prefixed evt_, so strip the prefix before comparing. Deduplicate on it: a retry carries the same id.

SB-Event-Namestring required

The event name, the same as the envelope's type.

Content-Typestring required

Always application/json.

User-Agentstring required

Always Subscriby-Webhooks/1.0.

Payload

idstring required

A ULID unique to the event, prefixed evt_. Every retry carries the same id, so it is the key to deduplicate on.

type'subscription.cancellation_feedback' required

The event name, always subscription.cancellation_feedback here.

created_atstring date-time required

When the event was emitted, server time, ISO 8601.

api_versionstring required

The contract version of the payload shape, 2026-05-01 today. A breaking change to a shape ships under a new version.

project_idstring uuid nullable required

The project the event belongs to; null for team-scoped and billing events.

Response

Your endpoint acknowledged the delivery. Any 2xx status within 30 seconds marks it delivered; the response body is ignored.

Changes

Webhooks have no change history: a webhook is keyed by its event name rather than a path and method, so no recorded change can name it.