Retrieves a single newsletter by id, including its full recipient list and attachments.
AuthorizationRequiredBearer <token>API key as Bearer token
In: header
idRequiredstringNewsletter id, discoverable via list_newsletters
fieldsstringComma-separated list of fields to return. Valid: id, hostId, subject, body, sent, recipient_emails, recipient_phonenumbers, event_refs, timeslot_refs, date_sent, footer_image, reply_to_email, automatic, display_name, content_blocks, viewport_data, data_version, sync_event_recipients, recipient_count, attachments, sparkpost_metrics, createdAt, updatedAt. Omit for all fields.
Create Newsletter
Creates a new newsletter (draft by default). Compose the email body through 'viewport_data' (structured site-builder content) — do NOT supply pre-rendered HTML; the send flow renders viewport_data into HTML for you. Recipient emails with typo-looking domains (e.g. gmial.com) are stripped before persistence.
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.