pass_series.* events

A capped season ticket sold its last seat.

When this fires

A purchase took the last seat on a series with a Seat Limit. The season is now sold out: its portal card reads Sold out, but a checkout already in flight is not blocked; the seat cap is only claimed once the payment lands, so a late buyer can pay, be given nothing, and be told to ask the organiser for a refund. Treat this event as the cue to stop promoting the season yourself.

Fires at the transition, once. An endpoint told this on every subsequent read would be told a fact rather than an event.

Caveats

  • Sold out is not permanent. A seat is released when a holder cancels or is refunded, and the series goes back on sale, at which point a later purchase can exhaust it again and emit this a second time. Treat it as a state change, not a terminal state.
  • Only holders who actually hold the series consume a seat. A checkout that was started and abandoned, or a payment that never cleared, does not.
  • A series with no Seat Limit never emits this at all.
  • Raising the cap does not emit anything. If you are tracking availability, read seats_remaining on the plan rather than inferring it from this event alone.

Related events

  • pass_series.purchased: every purchase, each carrying seats_remaining.
  • plan.deactivated: the series coming off sale for good once its dates have run.
postWebhookpass_series.seats_exhausted

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'pass_series.seats_exhausted' required

The event name, always pass_series.seats_exhausted 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.