Checks whether a UPI ID (Virtual Payment Address, e.g. 9999999999@ybl) exists and returns the name registered against it, as canonical fields (vpa_holder_name, vpa, is_valid, name_match, name_match_score, extras).

Response contract: A successful verification returns HTTP 200 with status: "success", error_code: null, and a populated data object. A definitive no-record / invalid result (the UPI ID does not exist) ALSO returns HTTP 200 with status: "success", but carries a non-null error_code and data: null — every 2xx response is status: "success", so do NOT distinguish a full-success verdict from a no-record one by status; branch on error_code (null = found, a non-null IDTO_2xx = not found). Only a raised error returns status: "error". Every response carries billed (whether the call was charged). All codes, messages and HTTP statuses are identical regardless of the underlying vendor. Authenticate with your X-Client-ID and X-API-KEY headers.

Codes: IDTO_202 (2xx, UPI ID invalid or does not exist — a definitive, chargeable verdict; the SAME universal no-record code used by every v2 product), IDTO_001 (missing or malformed UPI ID, 400), IDTO_009 (insufficient credits, 402), IDTO_006 (rate limited, 429), IDTO_007 (config error, 500), IDTO_008 (service busy, 503).