Access is restricted to shared mailboxes belonging to the authenticated customer.
Personal mailboxes and merged tickets are excluded; archived tickets remain accessible.
Reading does not change the ticket status, mark it as read, send mail or create a draft.
An inaccessible ticket and a missing ticket both return 404, including on sub-resources.

List responses contain data and pagination; detail responses return the ticket directly.
Without q, tickets are ordered by creation ID. With q, they are ordered by relevance,
then last message date and public ID. Emails are ordered oldest first, with ID as a tie-breaker.
Participants include archived participants so previous exchanges remain understandable.

Emails contain public, non-draft message text, quoted text, author, To/Cc recipients, direction,
sending status and date. Internal notes and drafts are excluded. HTML, attachments, inline images,
Bcc and generated download URLs are not exposed. Message text comes from the current record;
an email delivered without a text alternative exposes text derived from its HTML.
Ticket details contain active business references in context (type, public ID and role).
There is no separate description field: the conversation is available through /messages.