Newsletter and notifications

Newsletter contract#

The newsletter module exposes three operations:

• subscribe;
• status;
• unsubscribe.

The same page and API work with Resend Contacts or Beehiiv. Waitlist and signup flows call the stable operations rather than a vendor SDK.

Select a newsletter provider#

VITE_NEWSLETTER_PROVIDER=resend

Use beehiiv for the alternate adapter.

Preview mode#

NEWSLETTER_PREVIEW=true

The preview adapter stores deterministic subscription state so end-to-end tests can join, query, and unsubscribe without a vendor account.

Waitlist integration#

A first waitlist join can subscribe the selected newsletter provider and send a welcome email. The waitlist remains the durable source of queue position and referral state in D1.

Notification contract#

Discord and Feishu adapters receive bounded text through one sendNotification operation. Admin can choose a provider and exercise the integration from the product UI.

NOTIFICATION_PREVIEW=true

Preview mode confirms the request locally. Production requires the selected webhook URL.

Operational guidance#

• Keep audience status cache in KV and queue state in D1.
• Provide a working unsubscribe path.
• Never send administrator-only data through a public notification endpoint.
• Rate-limit automated notification sources when you add them.