New "quote_unavailable" locate error for unavailable prices

Trading API

Adds the quote_unavailable value to the LocateError and LocateQuoteError enums, returned when a closing price is unavailable for a locate quote or locate creation. Includes an HTTP 422 response example on POST /v1/locates.

Affected Endpoints

• POST /v1/locates
• GET /v1/locates/{locate_id}
• GET /v1/locates/quotes
• GET /v1/locates