The name arrives in all caps
/caller returns the CNAM record verbatim. FEDEX, not FedEx. Recasing a telco artifact means guessing, so we do not.
The phone network stores names in shouting.
GET /caller/+18004633339
{
"phone": "+18004633339",
"valid": true,
"country": "US",
"caller": "FEDEX"
}
caller is the CNAM record, the name that shows on a caller ID screen, exactly as the network stores it. That means all caps, fifteen characters, sometimes truncated mid-word. We ship it verbatim. Recasing FEDEX to Fedex is easy. Recasing MCDONALD to McDonald, MACDONALD, or Mcdonald is a guess, and a name cased wrong is worse than a name cased loud.
No record is an answer
CNAM is NANP only, so a valid GB number comes back caller null, free, no lookup spent. A US number with no record also comes back null, and that one is billed, because the network answered: nobody registered a name. 100 free a month, then a cent a name.
Try it
Call /caller with a 1-800 number you know. The name will be there, and it will be loud.