APIAPIPermanently deletes a newsletter. No soft-delete; the row is removed.
AuthorizationRequiredBearer <token>API key as Bearer token
In: header
idRequiredstringNewsletter id, discoverable via list_newsletters
Update Newsletter
Updates a newsletter's fields. Only provided fields change. Edit the email body via 'viewport_data' (structured site-builder content) — do NOT supply pre-rendered HTML; the send flow renders viewport_data on dispatch. If recipient_emails is supplied, typo-domain addresses are stripped.
Send Newsletter
Sends a newsletter through Sparkpost immediately. Stamps date_sent + sent=true on the persisted document. Seamless flow: call with just `id` once the draft has subject, recipients, viewport_data, and reply_to_email set. The server pulls those fields from the persisted doc and renders viewport_data → HTML server-side if no body is already rendered. Only pass subject/senderName/replyToEmail/recipients/html/attachments when you explicitly need to override the persisted values for this one send. The Sparkpost API must be configured server-side; calls return 503 when SPARKPOST_API_KEY is unset.