member.* events

A subscriber joins on a trial via cardless trial or access-code redemption.

When this fires

Two paths emit this event:

  • Cardless trial start: a subscriber begins a trial that took no payment method.
  • Access-code redemption on a trial plan: the redeemed plan sets trial_ends_at, so this fires in place of member.joined.

A Stripe checkout that begins with a trial window emits subscription.activated and subscription.trial_started, but no member.* join event. Like member.joined, this event covers zero-payment acquisition only.

The data keys differ by path. Absent keys are omitted entirely, not sent as null.

Caveats

  • A trial-joined member emits member.converted if the trial converts to paid, or rolls into member.churned once the trial expires without converting.
  • member.converted is currently emitted for Stripe only. Trials taken through other providers will not produce a conversion event.
  • subscription.created and subscription.trial_started fire alongside this event on both paths.

Related events

  • subscription.trial_started: fires alongside.
  • member.converted: fires on successful trial conversion (Stripe only).
  • member.joined: non-trial counterpart.
postWebhookmember.trial_joined

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'member.trial_joined' required

The event name, always member.trial_joined 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.