mail.google.com
Get Gmail thread
Input
threadId requiredHex legacy thread id, e.g. "19f2817451c27480". Must belong to the account being read — an id from another mailbox, or a deleted thread, is refused rather than waited out.
account optionalGoogle account email to act as (authuser=). Without it Gmail picks u/0, which is NOT deterministic when several accounts share the browser's cookie jar.
Output
n requiredsubject requiredmessages requiredthreadId required