The chat widget — What a visitor is allowed to read

Every message carries an explicit visible to the visitor flag, set when it is written and never inferred from who wrote it. The distinction is the whole point: an agent emailing a supplier about the same ticket produces a message from your side, and filtering on who wrote it would hand that supplier correspondence to the anonymous stranger who opened the chat. Internal notes are excluded for the same reason — nobody set the flag on them. The visitor sees you and them and never a staff name. They came to talk to a business rather than to Sarah in support, and the widget renders your side as your brand.