NewCaseMessageInput

input type

STAFF append-input for addCaseMessage: visibility is the staff author's CHOICE; the author stamps server-side.

Fields

Field	Type	Required	Notes
`caseId`	ID `ID!`	yes	The case appended to (tenant-scoped; a terminal case refuses CONFLICT/IMMUTABLE).
`body`	String `String!`	yes	The message body (1..4096).
`visibility`	String `String!`	yes	customer_visible \| internal_note (ruling — an internal note never crosses the consumer face).