Update localized content
Partially updates localized broadcast message content. Optional content must be exactly
one of mjml, html, text, or payload as the UI infers the editor type from that key.
Content can only be updated while the broadcast is a draft.
You cannot add a locale value on the default message content and you cannot clear the locale
field on a localized content record. Duplicate locale values are rejected with
409 Conflict.
Authorizations
Accepts either a raw API key or Bearer <key>.
Headers
Optional dated API revision for the request. Must use YYYY-MM-DD format.
^\d{4}-\d{2}-\d{2}$"2026-03-01"
Path Parameters
Broadcast ID.
Message ID.
Content ID.
Body
Partially update broadcast message content. The default content cannot gain
a locale and localized content cannot clear it; duplicate locales return
409.
Response
Broadcast content updated.
Content metadata for a broadcast message (one per locale / default). The
list response omits content; fetch a single record for the body.
BCP-47-style locale tag, or null for the default content variant.
Full body: exactly one of mjml, html, text, or payload is set.

